Ci a ion: Pham, N.N.; Bloudicek, R.;
Leuch e , J.; Rydlo, S.; Dong, Q.H.
Compa a i e Analysis o Ene gy
S o age and Bu e Uni s o Elec ic
Mili a y Vehicle: Su ey o
Expe imen al Resul s. Ba e ies 2024,
10, 43. h ps://doi.o g/10.3390/
ba e ies10020043
Academic Edi o : Hao Liu
Recei ed: 12 Decembe 2023
Re ised: 9 Janua y 2024
Accep ed: 17 Janua y 2024
Published: 23 Janua y 2024
Copy igh : © 2024 by he au ho s.
Licensee MDPI, Basel, Swi ze land.
This a icle is an open access a icle
dis ibu ed unde he e ms and
condi ions o he C ea i e Commons
A ibu ion (CC BY) license (h ps://
c ea i ecommons.o g/licenses/by/
4.0/).
ba e ies
A icle
Compa a i e Analysis o Ene gy S o age and Bu e Uni s o
Elec ic Mili a y Vehicle: Su ey o Expe imen al Resul s
Ngoc Nam Pham 1,2 , Radim Bloudicek 3,*, Jan Leuch e 1,4 , S anisla Rydlo 3and Quang Huy Dong 5
1Depa men o Mic oelec onics, Facul y o Elec ical Enginee ing and Communica ion, B no Uni e si y o
Technology, Technicka 3058/10, 616 00 B no, Czech Republic; [email p o ec ed] (N.N.P.);
[email p o ec ed] (J.L.)
2Ins i u e o Sys em In eg a ion, Le Quy Don Technical Uni e si y, Hoang Quoc Vie 236,
Hanoi 100000, Vie nam
3Depa men o Ai c a Technology, Facul y o Mili a y Technology, Uni e si y o De ence,
662 10 B no, Czech Republic; s anisla [email p o ec ed]
4Depa men o Elec ical Enginee ing in T anspo , Uni e si y o Pa dubice, S uden ska 95,
532 10 Pa dubice, Czech Republic
5Vie el A my Telecommunica ion Indus y Co po a ion, Hanoi 100000, Vie nam; [email p o ec ed]
*Co espondence: [email p o ec ed]
Abs ac : This pape deals wi h he analyses o ba e ies used in cu en mili a y sys ems o powe he
elec ic d i es o mili a y ehicles. The a icle ocuses on ba e y analyses based on ope a ional da a
ob ained om measu emen s a he han analyses o he chemical composi ion o he es ed ba e ies.
The au ho s o he a icle used hei expe ience om he de elopmen es -labo a o y o mili a y
echnology. This a icle p esen s a compa a i e analysis o exis ing and p omising echnologies in he
ield o ene gy s o age and bu e ing o mili a y elec ic ehicles. The o e iew o hese echnologies,
including he design, ope a ing p inciples, ad an ages, and disad an ages, a e b ie ly p esen ed o
p oduce heo e ical compa a i e analyses. Howe e , his a icle mainly ocuses on he expe imen al
e i ica ion o ope a ional abili y in a ied condi ions, as well as he compa ison and analysis o
hese esul s. The main pa o he a icle p o ides mo e expe imen al s udies on echnologies o
ene gy s o age and bu e ing using he esul s o se e al expe imen s conduc ed o demons a e
he beha io o each echnology in di e en wo king condi ions. The ou pu pa ame e s, as well
as he s a e o cha ge o each echnology’s samples, we e su eyed in a ious empe a u es and
loading cha ac e is ics. The esul s p esen ed in his pape a e expec ed o be use ul o op imizing
he selec ion o ene gy s o age and bu e ing solu ions o mili a y elec ic ehicles in di e en
applica ions and unc ional en i onmen s.
Keywo ds: ene gy s o age and bu e ; Lead-acid ba e ies; Nickel ba e ies; li hium-ion ba e ies;
Fuel Cell; supe capaci o ; mili a y elec ic ehicles
1. In oduc ion—Use o Ba e ies in Mili a y En i onmen
The ba le ield’s o m is changing day by day. The de elopmen o di e en scien i ic
and echnical disciplines opens up bo h oppo uni ies and challenges in educing human
casual ies in comba . In consequence, one o he mili a y ends ha is cons an ly e ol ing
is he digi iza ion o he ba le ield. To gi e an example, nowadays, all elemen s o he U.S.
A my comba eam a e in e connec ed wi hin he digi al ba le ield o imp o e comba
abili y and powe , as well as dec ease he casual ies [
1
]. The main esea ch, de elopmen ,
and expe imen a ion di ec ions in ba le ield digi iza ion can be lis ed as he ollowing [
2
]:
•A i icial In elligence (AI) and Machine Lea ning (ML);
•Robo ics and Au onomous Sys ems (RAS);
•Ne wo ked senso s and e ec o s;
•Ba le ield elec i ica ion;
Ba e ies 2024,10, 43. h ps://doi.o g/10.3390/ba e ies10020043 h ps://www.mdpi.com/jou nal/ba e ies
Ba e ies 2024,10, 43 2 o 29
•No el weapons.
As can be seen om he li e a u e [
2
], all componen s o he mili a y a e in e connec ed
and linked o he headqua e s. This s uc u e allows headqua e s o g asp si ua ions and
gi e app op ia e commands mo e easily. Comba elemen s a e also acili a ed o be e
coope a ion. Ba le ield digi iza ion is ob iously closely ela ed o he elec i ica ion o he
ba le ield; in o he wo ds, he use o elec ic ehicles and equipmen ins ead o ossil uel
ones in he mili a y. All he de elopmen ields men ioned abo e equi e elec ical and
elec onic sys ems o compu ing, communica ion, display, and so on. In addi ion, com-
pa ed wi h adi ional ossil uels, elec ic powe p o ides huge ad an ages in pe o mance,
simpli ica ion, and sus ainabili y. The elec i ica ion o he ba le ield leads o he issue o
ene gy s o age, which accumula es he elec ical ene gy o elec ical and elec onic sys ems
in mili a y equipmen , de ices, and ehicles. Figu e 1illus a es he need o ene gy s o age
in he mode n ba le ield. Almos all soldie equipmen and mili a y ehicles in e e y size
and e e y en i onmen equi e sui able ene gy s o age o hei unc ion [2–7]. As shown
in he ci ed li e a u e o his a icle, he au ho s mainly add essed he use o supe capaci o s
in elec ic d i es and he sizing o ene gy bu e s [2].
Ba e ies 2024, 10, x FOR PEER REVIEW 2 o 30
• Ba le ield elec i ica ion;
• No el weapons.
As can be seen om he li e a u e [2], all componen s o he mili a y a e in e con-
nec ed and linked o he headqua e s. This s uc u e allows headqua e s o g asp si ua-
ions and gi e app op ia e commands mo e easily. Comba elemen s a e also acili a ed
o be e coope a ion. Ba le ield digi iza ion is ob iously closely ela ed o he elec i i-
ca ion o he ba le ield; in o he wo ds, he use o elec ic ehicles and equipmen ins ead
o ossil uel ones in he mili a y. All he de elopmen ields men ioned abo e equi e elec-
ical and elec onic sys ems o compu ing, communica ion, display, and so on. In addi-
ion, compa ed wi h adi ional ossil uels, elec ic powe p o ides huge ad an ages in
pe o mance, simpli ica ion, and sus ainabili y. The elec i ica ion o he ba le ield leads
o he issue o ene gy s o age, which accumula es he elec ical ene gy o elec ical and
elec onic sys ems in mili a y equipmen , de ices, and ehicles. Figu e 1 illus a es he
need o ene gy s o age in he mode n ba le ield. Almos all soldie equipmen and mili-
a y ehicles in e e y size and e e y en i onmen equi e sui able ene gy s o age o hei
unc ion [2–7]. As shown in he ci ed li e a u e o his a icle, he au ho s mainly add essed
he use o supe capaci o s in elec ic d i es and he sizing o ene gy buffe s [2].
Figu e 1. Mode n ba le ield s uc u e [8].
Rela ed o he esea ch, de elopmen , and expe imen a ion in he RAS ield, in he
mode n ba le ield, all he componen s o he mili a y (ai o ce, g ound o ce, and sea/na-
al o ce) combine adi ional manned ehicles and eme ging unmanned ehicles (UVs)—
see Figu e 1. The use o mili a y UVs is no only limi ed o he mili a ies o la ge coun ies
bu also o small coun ies. Fo example, he A my o he Czech Republic o he People’s
A my o Vie nam ha e been, in ecen yea s, in eg a ed in o hei own adi ional s uc-
u e mili a y UVs o special missions such as econnaissance, demining, a ack, and es-
cues. Fo hese coun ies, he ecen ly sui able selec ion is he use o UVs wi h small sizes
and weigh s o sa e he de eloping cos s and de eloping ime, and mainly o sa e he
main enance equi emen s. As he solu ion o hese issues, he cu en end is o apply
hese ad an ages o elec ical d i es and powe s o mili a y UVs o elimina e he disad-
an ages o adi ional in e nal combus ion engines, such as noise, ca bon emissions,
lowe pe o mance, and highe equi emen s o engine main enance. Mili a y UVs a e
classi ied in o ou main g oups acco ding o hei unc ioning en i onmen : UAVs (Un-
manned Ae ial Vehicles) mo ing in he ai ; UGVs (Unmanned G ound Vehicles) mo ing
on he g ound; USVs (Unmanned Su ace Vehicles) mo ing on he sea su ace; and UUVs
(Unmanned Unde wa e Vehicles) mo ing in he wa e column.
In each ca ego y, UVs a e ca ego ized based on hei weigh . Fo example, he ca e-
go iza ion o UGVs is p esen ed in Table 1. The ca ego iza ion o UAVs can be ound in
[4]. As men ioned abo e, he use o elec ical d i es ins ead o in e nal combus ion engines
Figu e 1. Mode n ba le ield s uc u e [8].
Rela ed o he esea ch, de elopmen , and expe imen a ion in he RAS ield, in he
mode n ba le ield, all he componen s o he mili a y (ai o ce, g ound o ce, and sea/na al
o ce) combine adi ional manned ehicles and eme ging unmanned ehicles (UVs)—see
Figu e 1. The use o mili a y UVs is no only limi ed o he mili a ies o la ge coun ies
bu also o small coun ies. Fo example, he A my o he Czech Republic o he People’s
A my o Vie nam ha e been, in ecen yea s, in eg a ed in o hei own adi ional s uc u e
mili a y UVs o special missions such as econnaissance, demining, a ack, and escues.
Fo hese coun ies, he ecen ly sui able selec ion is he use o UVs wi h small sizes and
weigh s o sa e he de eloping cos s and de eloping ime, and mainly o sa e he main-
enance equi emen s. As he solu ion o hese issues, he cu en end is o apply hese
ad an ages o elec ical d i es and powe s o mili a y UVs o elimina e he disad an ages
o adi ional in e nal combus ion engines, such as noise, ca bon emissions, lowe pe o -
mance, and highe equi emen s o engine main enance. Mili a y UVs a e classi ied in o
ou main g oups acco ding o hei unc ioning en i onmen : UAVs (Unmanned Ae ial
Vehicles) mo ing in he ai ; UGVs (Unmanned G ound Vehicles) mo ing on he g ound;
USVs (Unmanned Su ace Vehicles) mo ing on he sea su ace; and UUVs (Unmanned
Unde wa e Vehicles) mo ing in he wa e column.
In each ca ego y, UVs a e ca ego ized based on hei weigh . Fo example, he ca ego-
iza ion o UGVs is p esen ed in Table 1. The ca ego iza ion o UAVs can be ound in [
4
].
As men ioned abo e, he use o elec ical d i es ins ead o in e nal combus ion engines
can help o educe noise, ca bon emissions, and main enance equi emen s. Ne e heless,
Ba e ies 2024,10, 43 3 o 29
cu en echnologies in he ield o elec ical powe sou ces ha e a numbe o ba ie s
ela ed o powe densi y and ene gy densi y. The e o e, his a icle ocuses mainly on he
small and po able UVs wi h powe in he ange o some kW, which is ad an ageous o use
hyb id o ull elec ic d i es wi h elec ical powe sou ces. La ge UVs wi h powe up o
100 kW a e s ill able o use elec ic d i es, bu equi e powe sou ces wi h highe ene gy, so
he use o powe sou ces cu en ly is disad an ageous and expensi e.
Table 1. Ca ego iza ion o AGVs [9].
Classes Weigh Ca y/T anspo Payload
Th owable UGVs Up o 2 kg Ve y limi ed payload
Backpackable UGVs Up o 25 kg Can be ca ied by 1 man Up o 5–10 kg
Po able UGVs Up o 75 kg Can be anspo ed by any ehicle, and Can be
loaded/ eloaded by 2 men Up o 30 kg
Ligh UGVs Up o 300 kg Can be anspo ed in adap ed ehicles Up o 150–200 kg
Medium UGVs Up o 1000 kg Can be anspo ed by aile /adap ed ehicles Up o 300–500 kg
Hea y UGVs Up o 5000 kg Can be anspo ed on he aile / owed Up o 2000 kg
Ve y hea y UGVs Abo e 5000 kg Can be anspo ed on he aile / owed
This a icle p esen s he expe imen al esul s o compa e cu en ene gy s o age ech-
nologies. F om he compa ison, he abili y o use each echnology and combine hese
echnologies o elimina e hei own weakness is discussed. Fo example, supe capaci o s
a e a o ably used as ene gy bu e s o ba e ies o p o ide he abili y o cha ge/discha ge
wi h high cu en le els, which small ba e ies a e no capable o doing. Such a solu ion
is e y ad an ageous o bo h sa ing he o al weigh o he ehicle (huge ba e y packs
a e no sui able) and sa ing ene gy ( he e iciency o supe capaci o s is much la ge han
cu en ba e ies) [
5
,
10
]. In pa icula , he li e a u e [
2
] p esen s he p oposal o a hyb id
powe supply concep o use by UAV applica ions.
Fu he mo e, i should be men ioned he e ha he s udies lis ed below, which o m a
easu e o e o ou expe imen ally based analyses, use he indings lis ed in he e e ences.
To summa ize he men ioned li e a u e used o he bene i o he a icle, we can di ide
i in o se e al ocuses. The li e a u e [
3
–
22
] is de o ed o indings in he ield o ene gy
s o age, ba e y cons uc ion, ba e y classi ica ion, e c. The li e a u e [
16
,
23
,
24
] deals wi h
he analyzes o he in luence o empe a u e and desc ibes he e ec s o empe a u e loading
o ba e ies. Analyses in he ield o ene gy s o age, he e ec s o empe a u e and de ailed
desc ip ion o ba e y echnologies [
16
–
18
,
22
,
25
–
27
], he use o ba e ies in elec ic d i e
applica ions [
4
–
9
,
14
,
19
–
21
,
28
–
31
], in he ield o expe imen al measu emen [
7
,
28
,
29
] and
in he ield o ene gy bu e s [
3
,
10
,
28
,
30
,
32
,
33
] should be men ioned he e. In his a icle, we
mainly ocus on he echnologies used in a mili a y en i onmen , whe e he main aim o he
a icle is no o p esen indi idual echnological solu ions. Ne e heless, he emphasis is
placed on he expe imen al e i ica ion o selec ed ba e ies wi h e e ence o he li e a u e
ha deals in de ail wi h measu ed ba e ies. De ailed in o ma ion abou he measu ed
ba e ies and possible echnologies is gi en in he ollowing sec ion.
2. In oduc ion—Ene gy S o age Technologies
2.1. Classi ica ion o Ene gy S o age Technologies
Ene gy s o age echnologies play an impo an ole in he ield o elec ical ene gy.
Fi s ly, hey help o cap u e gene a ed ene gy and dis ibu e i e ec i ely o la e use.
Secondly, hey can b idge he gap be ween he powe demand and he quali y as well
as he eliabili y o supplied powe [
11
–
13
]. The li e a u e [
2
] p o ides an o e iew o
he possibili ies o ene gy s o age echnologies. Acco ding o he o m o s o age, ene gy
s o age echnologies can be classi ied in o i e main g oups, which a e basically mechanical,
he mal, elec ochemical, elec ical, and hyd ogen-based s o age [13–15].
Ene gy s o age echnologies a e e y a ied and he e ogeneous. Thei a ie y depends
on applica ions and wo king condi ions. P ac ically, wo king condi ions, o example,
Ba e ies 2024,10, 43 4 o 29
empe a u e, mus be conside ed. These echnologies a e b ie ly p esen ed and compa ed
o selec he mos sui able echnologies o use in mili a y elec ic ehicles (EVs).
Mechanical s o age echnologies s o e ene gy in he o m o g a i a ional po en ial
ene gy (g a i y s o age echnologies), kine ic ene gy ( lywheels), and po en ial ene gy o
comp ession (comp essed ai ene gy s o age o pumped hyd o s o age).
The p inciple o he mal s o age echnologies is ha excess elec ical ene gy is used o
hea o cool down app op ia e special ma e ials. When elec ical ene gy is equi ed, he
e e se p ocess is called o eco e he ene gy. The e a e wo o ms o he mal s o age—
sensible he mal s o age and la en hea s o age [
15
]. The li e a u e [
2
] p o ides a clea
classi ica ion o ene gy s o age echnologies. Elec ochemical s o age echnologies a e
basically ba e y echnologies ha use a ious elec ochemical eac ions o con e ene gy
be ween chemical o m and elec ical o m [
4
,
16
]. The ba e y echnologies can be classi ied
acco ding o he ma e ials used o elec ochemical eac ions. The mos used ba e y ypes
a e Lead-acid ba e ies, Nickel ba e ies, and li hium ba e ies.
Elec ical s o age echnologies use supe capaci o s and supe conduc ing magne ic
sys ems o s o e ene gy in he o m o elec ic and elec omagne ic ields. Thanks o he
almos -ideal p ope ies o hese sys ems, ene gy can be s o ed wi h minimal loss. Howe e ,
he p ice o hese “supe -sys ems” is an essen ial p oblem. In hyd ogen-based sys ems,
elec ici y is used o elec olyze wa e in o oxygen and hyd ogen, which is s o ed in high-
p essu e con aine s o di ec combus ion o gene a ion o elec ici y ia Fuel Cells.
This pape mainly ocuses on elec ochemical s o age (ba e y echnologies). In com-
pa ison o mechanical s o age and he mal s o age, ba e y echnology is con enien o
mili a y use on he ba le ield due o i s small size, mechanical and he mal s abiliza ion,
and easy main enance (no special ma e ials a e equi ed). In addi ion, his a icle also
shows some achie ed esul s in s udies abou elec ical s o age using supe capaci o s, and
hyd ogen-based s o age wi h Fuel Cells. Nume ous s udies compa e he ad an ages and
disad an ages o di e en ene gy s o age echnologies. This a icle compa es and analyses
hem; howe e , i mainly ocuses on he iewpoin o uses in mili a y elec ic ehicles.
2.2. Cons uc ion o Selec ed Ba e y Technologies
The ba e y is de ined as a de ice ha con ains ene gy (in he o m o chemical ene gy)
in i s ac i e ma e ials. I equi ed, con ained chemical ene gy is con e ed di ec ly in o
elec ical ene gy by he elec ochemical oxida ion- educ ion eac ion. Each ba e y con ains
h ee main pa s [16]:
1.
The anode (nega i e elec ode) is oxidized du ing he elec ochemical eac ion and
gi es up he elec ons o he ex e nal ci cui (ex e nal load).
2.
The ca hode (posi i e elec ode) is educed du ing he elec ochemical eac ion and
accep s elec ons om he ex e nal ci cui (ex e nal load).
3.
The elec oly e (ionic conduc o ) p o ides he medium o ans e ing elec ic cha ge/
ions inside he ba e y be ween he anode and ca hode.
Ba e ies a e classi ied in o p ima y ba e ies, which canno be echa ged elec ically
in an e ec i e way, and seconda y o echa geable ba e ies, which a e capable o being
echa ged elec ically. Each ype o ba e y has bo h ad an ages and disad an ages and
can be used in di e en applica ions. P ima y ba e ies a e inexpensi e, ligh weigh , high-
ene gy-dense, and easy o use. Hence, hei common applica ions a e ligh weigh powe
sou ces o po able elec ical and elec onic de ices. In addi ion, he bigges ad an age o
seconda y ba e ies is he abili y o elec ically echa ge, which p ima y ba e ies canno
ha e. As a esul , echa geable ba e ies a e sui able o use in ene gy s o age sys ems.
The main cha ac e is ics o a ba e y depend on i s anode and ca hode ma e ials. The
ma e ial used in he ba e y undamen ally in luences he esul ing pa ame e s o he
ba e y. Fo example, using li hium me al oxide o li hium me al phospha e as ca hode
ma e ial can inc ease he a e capabili y and cyclabili y. In addi ion, hey can imp o e he
ollowing pa ame e s: he s abili y, s o age capaci ies, and a e pe o mance o li hium-ion
ba e ies. Howe e , his a icle does no aim o ocus on he analysis o possible ma e ials
Ba e ies 2024,10, 43 5 o 29
o achie e be e ba e y beha io in a mili a y en i onmen bu is based on he conclusions
o scien i ic a icles ocused on imp o ing he s abili y and a e pe o mance o li hium-ion
ba e ies [
17
] and ecen ad ances on ma e ials o li hium-ion ba e ies [
18
] In addi ion, we
can men ion he impo ance o using ma e ial li hia ed g aphi e wi h ega d o achie ing
lowe weigh and abili y in ex eme condi ions.
The main ba e y ypes in mili a y applica ions, acco ding o anode and ca hode
ma e ials, a e Lead-Acid, Ni-Cd, Ni-MH, and li hium-ion ba e ies [
4
,
16
]. The li e a u e [
16
]
con ains e y de ailed in o ma ion on ba e y echnology and also deals wi h he ba e y
heo y, and desc ibes indi idual echnological solu ions.
2.2.1. Lead-Acid Ba e ies
Lead-acid ba e ies ha e been he mos widely used ba e y ype h oughou he
his o y o anspo a ion. Almos all ci il and mili a y ehicles adi ionally use Lead-acid
ba e ies as he powe pa o he SLI (s a ing, ligh ing, and igni ion) sys em. Ano he
common applica ion o his ba e y is a powe bu e , e.g., in a UPS (Unin e up ible powe
supply) sys em. As he ca hode ma e ial, Lead-acid ba e ies use lead dioxide (PbO
2
), while
pu e me allic lead (Pb) is used as he anode ma e ial. The elec oly e o a Lead-acid ba e y
is a sul u ic acid solu ion. The elec ochemical eac ions o he discha ging p ocess a e he
ollowing [13–16,19,20]:
Anode eac ions : Pb →Pb2++2e−, (1)
Pb2++SO2−
4→PbSO4(2)
Ca hode eac ions : PbO2+4H++2e−→Pb2++2H2O, (3)
Pb2++SO2−
4→PbSO4(4)
O e all eac ion : Pb +PbO2+2H2SO4→2PbSO4+2H2O (5)
2.2.2. Nickel Ba e ies
Nickel ba e ies we e one o he mos used ba e y ypes in he 20 h cen u y. Cu en ly,
hey a e s ill impo an ba e y echnology in special applica ions, no only in he mili a y
bu also in he ae ospace ield. Figu e 2shows he example o 24 V/22 A Nickel Cadmium
ba e y used in mili a y ai c a , which consis s o 20 cells in se ies.
Ba e ies 2024, 10, x FOR PEER REVIEW 6 o 30
Anode eac ions: Cd + 2 OH → Cd󰇛OH󰇜+2 e
 (6)
Ca hode eac ions: 2 NiO󰇛OH󰇜+2 H
O+2 e
 → 2 Ni󰇛OH󰇜+2 OH
 (7)
O e all eac ion: 2 NiO󰇛OH󰇜+Cd+2 H
O → 2 Ni󰇛OH󰇜+Cd
󰇛OH󰇜 (8)
(a) (b)
Figu e 2. The Ni-Cd ba e y in ai c a echnology: (a) a ia ion ba e y package; (b) in e nal iew
o ba e y cell a angemen .
Ni-MH ba e ies use Me al Hyd ide as anode ma e ial ins ead o he oxic ma e ial
Cadmium (Cd), while he ca hode is s ill om Nickel(III) oxide hyd oxide (NiOOH).
The e o e, he elec ochemical eac ions du ing discha ging a e he ollowing:
Anode eac ions: MH + OH → M+HO+e
, (9)
Ca hode eac ions: NiO󰇛OH󰇜+H
O+e
 → Ni
󰇛OH󰇜+OH
, (10)
O e all eac ion: NiO󰇛OH󰇜+MH→ Ni
󰇛OH󰇜+M (11)
whe e MH s ands o Me al Hyd ide, and M s ands o me al [16,19,21].
2.2.3. Li hium-Ion Ba e ies
Nowadays, he mos used ba e y echnology is a li hium-ion (Li-ion) ba e y. Li-ion
ba e ies exis in almos e e y elec ical and elec onic de ice in he 21s cen u y. Thei
ad an ages o small size, ligh weigh , and high capaci y make hem e y sui able o e e y
applica ion. Thei popula i y is e lec ed in a ie ies o shapes, om small single calluses
on po able elec onic de ices o huge ba e y packs o demanding use, e.g., in ai c a .
Figu e 3 shows some diffe en shapes o Li-ion ba e ies, which a e used in lap ops, po -
able elec onic de ices, d ones, and small UVs in ou o he wo ks [4–42]. The cons uc ion
o wo ypical Li-ion ba e y cells—a wound cylind ical cell and a polyme cell is also il-
lus a ed in Figu e 3. These ba e y cells can be connec ed in o la ge ba e y packs wi h
highe ou pu ol age (ba e y cells a e connec ed in se ies) o highe capaci y (ba e y
cells a e connec ed in pa allel) o combine hese opologies o achie e bo h highe ou pu
ol age and highe capaci y. 1 I is necessa y o s a e he e ha conduc i i y o elec odes is
one o he mos impo an ac o s affec ing he in e nal esis ance o ba e y in gene al and
Li-ion ba e y in pa icula . As shown below, he pe o mance o he ba e y is signi ican ly
affec ed by i s in e nal esis ance. Fo example, he in e nal esis ance causes in e nal Joule
Figu e 2. The Ni-Cd ba e y in ai c a echnology: (a) a ia ion ba e y package; (b) in e nal iew o
ba e y cell a angemen .
Unlike Lead-acid ba e ies, which use dilu e sul u ic acid as an elec oly e, Nickel
ba e ies use an aqueous solu ion o alkali me al hyd oxide (KOH o NaOH) as an elec-
oly e, which b ings nume ous bene i s. Fi s ly, he elec ode ma e ials a e less eac i e

Ba e ies 2024,10, 43 6 o 29
wi h alkaline han wi h acidic elec oly es. Secondly, he alkaline elec oly e only anspo s
O
2−
o OH
−
ions, and he elec oly e does no change i s composi ion o concen a ion
(compa ed wi h he case o Lead-acid ba e ies). The wo mos common ypes o Nickel
ba e ies a e Ni-Cd (Nickel-Cadmium) and Ni-MH (Nickel Me al Hyd ide) ba e ies.
Ni-Cd ba e ies use Cadmium (Cd) as anode ma e ial, while he ca hode is om
Nickel(III) oxide hyd oxide (NiOOH). The elec ochemical eac ions du ing discha ging a e
p esen ed below, which is clea ha he alkali me al hyd oxide elec oly e is no consumed
in hese eac ions [16,19,21]:
Anode eac ions : Cd +2OH−→Cd(OH)2+2e−(6)
Ca hode eac ions : 2NiO(OH)+2H2O+2e−→2Ni(OH)2+2OH−(7)
O e all eac ion : 2NiO(OH)+Cd +2H2O→2Ni(OH)2+Cd(OH)2(8)
Ni-MH ba e ies use Me al Hyd ide as anode ma e ial ins ead o he oxic ma e ial
Cadmium (Cd), while he ca hode is s ill om Nickel(III) oxide hyd oxide (NiOOH).
The e o e, he elec ochemical eac ions du ing discha ging a e he ollowing:
Anode eac ions : MH +OH−→M+H2O+e−, (9)
Ca hode eac ions : NiO(OH)+H2O+e−→Ni(OH)2+OH−, (10)
O e all eac ion : NiO(OH)+MH →Ni(OH)2+M (11)
whe e MH s ands o Me al Hyd ide, and M s ands o me al [16,19,21].
2.2.3. Li hium-Ion Ba e ies
Nowadays, he mos used ba e y echnology is a li hium-ion (Li-ion) ba e y. Li-ion
ba e ies exis in almos e e y elec ical and elec onic de ice in he 21s cen u y. Thei
ad an ages o small size, ligh weigh , and high capaci y make hem e y sui able o e e y
applica ion. Thei popula i y is e lec ed in a ie ies o shapes, om small single calluses
on po able elec onic de ices o huge ba e y packs o demanding use, e.g., in ai c a .
Figu e 3shows some di e en shapes o Li-ion ba e ies, which a e used in lap ops, po able
elec onic de ices, d ones, and small UVs in ou o he wo ks [
4
–
42
]. The cons uc ion
o wo ypical Li-ion ba e y cells—a wound cylind ical cell and a polyme cell is also
illus a ed in Figu e 3. These ba e y cells can be connec ed in o la ge ba e y packs wi h
highe ou pu ol age (ba e y cells a e connec ed in se ies) o highe capaci y (ba e y
cells a e connec ed in pa allel) o combine hese opologies o achie e bo h highe ou pu
ol age and highe capaci y. I is necessa y o s a e he e ha conduc i i y o elec odes is
one o he mos impo an ac o s a ec ing he in e nal esis ance o ba e y in gene al and
Li-ion ba e y in pa icula . As shown below, he pe o mance o he ba e y is signi ican ly
a ec ed by i s in e nal esis ance. Fo example, he in e nal esis ance causes in e nal Joule
hea ing and ou pu ol age d op. The e o e, he conduc i i y o elec odes is impo an o
he ab ica ion o Li-ion ba e ies.
Li hium-ion ypes o ba e ies a e desc ibed in de ail in he li e a u e [16]. Rega ding
he echnologies used, we can men ion he Li hium-Ti anium-Oxide (LTO) echnology,
which is cha ac e ized by a lowe nominal ol age. Thei ad an age is he abili y o ope a e
a low- empe a u e le els. The disad an age is he low speci ic ene gy densi y ( ypically
50–80 Wh/kg). Ano he a ian is Li hium-Cobal (LCO) echnology, which achie es
good speci ic capaci ies. The nominal ol age o he cells is 3.6 V, bu he cells ha e a
sho e se ice li e and a low speci ic powe . This echnology is cu en ly being eplaced
wi h a ocus on inc easing li espan and using en i onmen ally iendly ma e ials. Li hium-
Manganese (LMO) echnology p o ides highe speci ic ba e y capaci ies and sligh ly lowe
speci ic ene gy densi y. The se ice li e is also a he low, bu ega ding he empe a u e
load, his echnology is in e es ing, as he mal decomposi ion occu s a empe a u es o up
o 250 ◦C [16].
Ba e ies 2024,10, 43 7 o 29
Ba e ies 2024, 10, x FOR PEER REVIEW 8 o 30
Fo simpli ica ion, he elec ochemical eac ions o discha ging a e w i en o he li hium
me al oxide ca hode [16]:
Anode eac ions: LiC → C + x Li+x e
 (12)
Ca hode eac ions: LiMO+
y
Li+
y
e→LiMO
 (13)
O e all eac ion:
y
LiC+x Li
MO→x LiMO
+
y
C (14)
Figu e 3. Typical Li-ion ba e y cells and hei cons uc ion [16].
As men ioned, one op ion is o use li hia ed g aphi e. Ano he possible combina ion
as an anode ma e ial is aluminum oil in he ab ica ion o li hium-ion ba e ies. Ma e ials
ha appea sui able o u he ba e y de elopmen a e aluminum, indium, in, and lead
o di ec use as ac i e ma e ials, which can imp o e he ene gy densi y a leas 40%. These
solu ions a e be e han solu ions based on g aphi e-based echniques. In addi ion, hese
ma e ials will allow high capaci ies and o ma ion efficiencies [22].
The in luence o used ma e ials also has an in luence on he ene gy densi y alue.
Cu en ly, Li-ion ba e ies each he highes ene gy densi y alues. The ene gy densi y o
Li-ion cells can each he alue up o 265 Wh/kg. In addi ion, he densi y o Ni-Cd ba e -
ies, which a e cu en ly used in he d i es o s ill-used mili a y sys ems, can be men ioned.
The ene gy densi ies o he Ni-Cd ba e ies a e abou 75 Wh/kg. This a icle also add esses
he issues o using supe capaci o echnology. Supe capaci o s each e y low ene gy den-
si y alues (abou 25 Wh/kg). On he o he hand, hey excel in pa ame e s o powe den-
si y and cha ge/discha ge efficiency. The Fuel Cell echnology ha is also compa ed in his
a icle wi h Li-ion ba e ies eaches alues o ene gy densi y o abou 40 kWh/kg. I is
ob ious ha each echnology has i s ad an ages; he e o e, o example, some disad-
an ages o he echnology can be compensa ed by expensi e echnology (in e ms o p ice
and ma e ial), o i is possible o use wo diffe en echnologies (in e ms o p ice and
ma e ial) in combina ion so ha he esul ing p ope ies a e be e .
In conclusion o his sec ion, we p esen he chosen main pa ame e s o ba e ies used
o compa e Ea h-sensi i e echnologies. One o he pa ame e s is he nominal ol age and
nominal capaci y o he ba e y. Lead-acid ba e y eaches a ol age pe cell o 2 V, Ni-Cd
1.2 V, unlike Li-ion echnology, which is cha ac e ized by 3.6 V pe cell. A highe ol age
on he cell enables highe powe and ene gy densi y alues, as well as be e load ol age
limi s. Rega ding ene gy densi y, Li-ion echnology achie es he highes alues o 200–300
Wh/kg among moni o ed elec ochemical ba e ies. Fuel Cell echnology achie es highe
alues o ene gy densi y. F om he poin o iew o he powe densi y pa ame e , i ap-
pea s o be he bes echnology based on supe capaci o s. Ve y good esul s we e achie ed
Figu e 3. Typical Li-ion ba e y cells and hei cons uc ion [16].
The mos success ul echnology is he Li hium-Nickel-Manganese-Cobal (NMC)
a ian , which o e s good speci ic powe and ene gy densi y, as well as a ela i ely long
se ice li e, which is up o 7–9 imes be e han he LCO and LMO a ian s. Howe e ,
conside ing he use o cobal , his op ion is no p omising. Tha is why Li hium-I on-
Phospha e (LFP) echnology is used oday and is ypically used in ac ion elec ic d i es.
The s abili y o LFP is be e compa ed o he abo e-men ioned echnologies, and i is
highe han 250
◦
C wi h espec o he mal decay. The ad an age is also he lack o
use o cobal and a e me als in he cons uc ion, hen he ba e y can be economically
ad an ageous and also ecological. Li e ime is 2–5
×
longe compa ed wi h NMC. Li hium-
Nickel-Cobal -Aluminum (NCA) echnology wi h a highe speci ic ene gy densi y han
NMC is also known [
16
]. Howe e , he mal decomposi ion is a 150 deg ees. Howe e , he
use in he u u e canno be assumed wi h ega d o he use o cobal , bu also o he mal
decomposi ion. I is no possible o lis all possible a ian s, bu we ha e only lis ed
he possible ypes o Li-ion ba e ies o he needs o elec ic ac ion o summa ize. To
be expec ed, li hium ba e ies a e based on li hium-sul u o li hium-ai wi h he aim o
achie ing highe speci ic capaci ies. Fo he sake o comple eness, he e we also men ion
he Sodium-Ion (Na-Ion) a ian , which eplaces li hium wi h sodium. So, ins ead o
he li hium ca hode, sodium is used. The main ad an age o his solu ion is he na u al
occu ence o sodium and he ecological aspec s. Howe e , in applica ions o use in elec ic
ac ion, he Sodium-Ion a ian achie es lowe ene gy densi y and also exhibi s lowe
cycle li e. In ou a icle, we do no deal wi h his echnology because hey a e no used
in mili a y echnologies and a e complica edly a ailable. Howe e , hei de elopmen
and esea ch can be expec ed because hey each 3
×
highe capaci y han LTO, simila
o LFP echnology, bu 2
×
lowe han NCA [
16
]. We can also men ion he echnological
a ian Zinc-Ion (Zn-ion), which is a possible al e na i e o li hium-ion ba e ies because
Zinc-Ion, like Na-Ion, is sa e o he need o elec ic ac ion. I can be expec ed ha non-
li hium ba e ies will be used in he u u e wi h sa e y and en i onmen al conside a ions in
mind [
16
]. Howe e , simila o he abo e conclusion, we do no ocus on his echnology o
non-li hium ba e ies wi h ega d o hei limi ed use in mili a y echnology, bu i can be
expec ed p ecisely o secu i y and sa e y easons ha hey will be deployed in he u u e.
Howe e , as s a ed in he in oduc ion, in his a icle, we y o p esen he echnologies
ha a e cu en ly used on mili a y icycles, whe e li hium-based echnology has o e aken
hese days. The e o e, wi h ega d o mili a y needs, echnological a ian s o Li-ion
echnology p e ail. Cu en ly, Li-ion ba e y echnologies based on li hium me al oxide
o li hium me al phospha e as ca hode ma e ial and li hia ed g aphi e as anode ma e ial;
Lead-acid ba e ies use lead dioxide (PbO
2
) as ca hode ma e ial and pu e me allic lead
as anode ma e ial [
16
]. The esul s o measu emen s conduc ed on hese ba e ies a e
p esen ed and discussed in he nex chap e s.
Ba e ies 2024,10, 43 8 o 29
The ca hode ma e ial o Li-ion ba e ies is li hium me al oxide (LiMO
2
) o li hium
me al phospha e (LiMPO
4
), while he anode ma e ial is ypically li hia ed g aphi e (Li
x
C).
Fo simpli ica ion, he elec ochemical eac ions o discha ging a e w i en o he li hium
me al oxide ca hode [16]:
Anode eac ions : LixC→C+xLi++xe−(12)
Ca hode eac ions : Li1−yMO2+yLi++ye−→LiMO2(13)
O e all eac ion : yLixC+xLi1−yMO2→xLiMO2+yC (14)
As men ioned, one op ion is o use li hia ed g aphi e. Ano he possible combina ion
as an anode ma e ial is aluminum oil in he ab ica ion o li hium-ion ba e ies. Ma e ials
ha appea sui able o u he ba e y de elopmen a e aluminum, indium, in, and lead
o di ec use as ac i e ma e ials, which can imp o e he ene gy densi y a leas 40%. These
solu ions a e be e han solu ions based on g aphi e-based echniques. In addi ion, hese
ma e ials will allow high capaci ies and o ma ion e iciencies [22].
The in luence o used ma e ials also has an in luence on he ene gy densi y alue.
Cu en ly, Li-ion ba e ies each he highes ene gy densi y alues. The ene gy densi y
o Li-ion cells can each he alue up o 265 Wh/kg. In addi ion, he densi y o Ni-Cd
ba e ies, which a e cu en ly used in he d i es o s ill-used mili a y sys ems, can be
men ioned. The ene gy densi ies o he Ni-Cd ba e ies a e abou 75 Wh/kg. This a icle
also add esses he issues o using supe capaci o echnology. Supe capaci o s each e y
low ene gy densi y alues (abou 25 Wh/kg). On he o he hand, hey excel in pa ame e s
o powe densi y and cha ge/discha ge e iciency. The Fuel Cell echnology ha is also
compa ed in his a icle wi h Li-ion ba e ies eaches alues o ene gy densi y o abou
40 kWh/kg. I is ob ious ha each echnology has i s ad an ages; he e o e, o example,
some disad an ages o he echnology can be compensa ed by expensi e echnology (in
e ms o p ice and ma e ial), o i is possible o use wo di e en echnologies (in e ms o
p ice and ma e ial) in combina ion so ha he esul ing p ope ies a e be e .
In conclusion o his sec ion, we p esen he chosen main pa ame e s o ba e ies used
o compa e Ea h-sensi i e echnologies. One o he pa ame e s is he nominal ol age
and nominal capaci y o he ba e y. Lead-acid ba e y eaches a ol age pe cell o 2 V,
Ni-Cd 1.2 V, unlike Li-ion echnology, which is cha ac e ized by 3.6 V pe cell. A highe
ol age on he cell enables highe powe and ene gy densi y alues, as well as be e
load ol age limi s. Rega ding ene gy densi y, Li-ion echnology achie es he highes
alues o 200–300 Wh/kg among moni o ed elec ochemical ba e ies. Fuel Cell echnology
achie es highe alues o ene gy densi y. F om he poin o iew o he powe densi y
pa ame e , i appea s o be he bes echnology based on supe capaci o s. Ve y good
esul s we e achie ed wi h Li-ion-based echnology. The weakes powe densi y alues o
50–75 Wh/kg a e achie ed wi h Fuel Cells and Ni-Cd and simila ba e y echnologies. As
was men ioned abo e, o e alua e no only he e ec i eness o he ba e y bu also om he
poin o iew o he possibili y o speed cha ging, i is necessa y o ocus on he pa ame e
o he in e nal esis ance o he ba e y. In his ega d, Li-ion, supe capaci o s and Lead-acid
ba e ies achie e be e alues compa ed wi h o he echnologies. The in e nal esis ance
pa ame e is also closely ela ed o he wo king cycles o he ba e y oge he wi h he
ma e ial used. Li-ion ba e ies ha e a lowe numbe o cycles, bu he pa ame e s o he
size o he discha ge p ods and he empe a u e ange can be op imized. Simila o he
combina ion o powe and ene gy densi y pa ame e s, i can be modi ied ei he by using
expensi e echnology o by combining di e en ypes o echnologies ha would help each
o he o imp o e he pa ame e s. Fo example, in combina ion wi h supe capaci o s, i is
possible o imp o e he pa ame e s o powe densi y and li e cycle li e o Li-ion ba e ies.
De ailed analyses o di e en ba e y pa ame e s a e p esen ed below, whe e we assess
indi idual echnologies based on expe imen al analyses and compa e hem o heo e ical
(expec ed) pa ame e s.
Ba e ies 2024,10, 43 9 o 29
We also ocused on elec ical pa ame e s o he needs o elec ic d i es. I is also
necessa y o men ion he e a pa ame e ela ed o he logis ical use o accumula o s in
p ac ice, i.e., sel -discha ge o ba e ies, which is ela ed o ba e y s o age. The sel -
discha ge e ec causes he loss o ba e y capaci y. The sel -discha ge alue o Lead-acid
echnology eaches up o 4–8% capaci y loss pe mon h. Ni-Cd and Ni-Mh echnology
ypically each alues o up o 20–30% o he nominal capaci y pe mon h. Wi h Li-ion
echnology, up o 2–3% pe mon h is achie ed. F om he poin o iew o sel -discha ge,
Li-ion echnology is he mos ad an ageous. One o he easons why Li-ion echnology
is used in he ba e y ma ke is p ecisely he ac ha i achie es he lowes deg ee o
sel -discha ge, and his is e y impo an o he needs o logis ics in he mili a y.
2.3. Fuel Cell and Supe capaci o Cons uc ion
In ecen yea s, he in e es in Fuel Cell echnology in he au omo i e indus y has
been apidly inc easing. Cu en de elopmen in his ield opens a huge change o he use
o his echnology in UVs. The Fuel Cell (FC) is a gal anic de ice ha con e s he chemical
ene gy o a uel and oxidan o elec ical ene gy. The con e sion is con inuous as long as
he uel and oxidan a e ed o he elec odes ( om an ex e nal sou ce). The di e ence
be ween FCs compa ed wi h ba e ies is ha ene gy is s o ed ex e nally, which heo e ically
allows FC sys ems o gene a e elec ici y con inuously. Table 2p esen s he main ypes o
FC sys ems based on he elec oly e ma e ials and ope a ing empe a u e [4,5,16].
Table 2. Ca ego iza ion o FC sys ems [16].
FC Types Sho Name Elec oly e Ope a ing
Tempe a u e Main Fea u es
Solid Oxide SOFC
Solid
oxygen-ion-conduc ing
me al oxide
1000 ◦CE iciency up o 60%, high-g ade
hea gene a ion
Mol en Ca bona e MCFC Mixed alkali-ca bona e,
mol en sal 650 ◦C
has been de eloped o con inuously
ope a ing acili ies and can use
coal-based/ma ine diesel uels
Phospho ic Acid PAFC Concen a ed
phospho ic acid 230 ◦CE iciency up o 85% (40% elec ici y,
45% hea )
Alkaline AFC Alkaline po assium
hyd oxide 70 ◦CE iciency up o 60%, used by NASA on he
manned space missions
P o on exchange
memb ane PEM
Pe luo ina ed ionome
polyme memb ane 70–85 ◦CRapid s a up ime has been designed o
anspo able and low-kW sys em
Di ec me hanol DMFC
Pe luo ina ed ionome
polyme memb ane 70–85 ◦CRapid s a up ime has been designed o
anspo able and sub-kW sys em
Regene a i e RFC
Closed-loop gene a o —an elec olyze
sepa a es wa e in o hyd ogen and oxygen,
which a e hen used o p oduce elec ici y
and wa e by FC
This a icle ocuses on low-kW UVs; he e o e, he mos sui able FC ype is PEM,
which has been designed o low-kW sys ems. The cons uc ion o a small PEM FC is
shown in Figu e 4, whe e inpu hyd ogen is s o ed in hyd ogen anks. Oxygen equi ed
by FCs can be supplied om a simila ank o di ec ly om he ai . The second solu ion
can cause a lack o oxygen and dec ease he e iciency o FCs when EVs ope a e in an
en i onmen wi h low oxygen concen a ion, o example, in he case o UAVs and UUVs.
Ba e ies 2024,10, 43 16 o 29
Ba e ies 2024, 10, x FOR PEER REVIEW 18 o 30
ound a he end o he discha ge p ocess, which can be a use ul e ec o es ima ing he
SoC (s a e o cha ge) o DoD (Dep h o Discha ge) o ba e ies in ope a ion.
(a)
(b)
Figu e 14. Discha ge cha ac e is ic a 25 °C: (a) Ni-Cd ba e y; (b) Ni-MH ba e y.
Figu e 15 shows he esul s o ano he expe imen , whe e he cha ge and discha ge
cha ac e is ics o Ni-MH we e moni o ed a di e en empe a u es while he cha ge and
discha ge cu en we e kep cons an a 1 A. Expe imen s we e conduc ed a 25 °C, 10 °C,
and −10 °C. The d ama ic decline o capaci y a nega i e empe a u e is clea ly p esen ed.
In discha ging du a ion, he es ed Ni-MH ba e y was able o discha ge only abou 20%
s o ed ene gy, in compa ison o discha ged ene gy a 10 °C and 25 °C. In cha ging du a-
ion, his decline is e en mo e signi ican . E en hough he ba e y ol age eaches he
highe alue a −10 °C, only o e 10% capaci y o he ba e y was cha ged, in compa ison
o he cha ged capaci y a 10 °C and 25 °C.
Figu e 15a also p esen s he dependence o Ni-MH ba e ies’ in e nal esis ance on
empe a u e. In he case o cons an discha ge ol age, he in e nal esis ance gene ally
inc eases wi h he dec ease in ope a ing empe a u e.
Figu e 15. Cha ac e is ics and capaci y o Nickel ba e ies a 25 °C, 10 °C, and −10 °C: (a) Ni-MH
ba e y discha ging a 1 A; (b) Ni-MH ba e y cha ging a 1 A.
3.5. Li hium-Ion Ba e ies
Li hium is he ba e y echnology nowadays, appea ing in a huge amoun o applica-
ions. Li hium is he ligh es me al and he leas dense solid elemen , making li hium ba -
e ies ake ad an age o ligh weigh , high ene gy, and powe densi y. The ene gy and
powe densi y o li hium ba e ies can be i e imes g ea e han Lead-acid o Ni-Cd
e ec o
in e nal
esis ance
e ec o
in e nal
esis ance
Quick ol age d op
Quick ol age d op
e ec o
discha ge cu en
e ec o
discha ge cu en
Figu e 12. Discha ge cha ac e is ic o a Lead-acid ba e y: (a) a 25 ◦C; (b) a 10 ◦C.
Figu e 12b does no show ano he case o cha ging he ba e y wi h a cu en o 10 A
because he in e nal esis ance o he ba e y has inc eased, so he ba e y shows signs o
o e load. The esul s o measu emen s a ound 10 A a e un epea able and depend on he
cu en s a e o he ba e y.
Figu e 13 shows he discha ge capaci y o he es ed Lead-acid ba e y a 10
◦
C and
25
◦
C wi h he discha ging cu en s 1 A and 2 A. The e ec o empe a u e is clea ly ealized.
In he case o 1 A discha ging cu en , he ba e y’s capaci y a 10
◦
C is only hal o he
capaci y a 25
◦
C. The low empe a u e signi ican ly dec eases he e iciency o in e nal
elec ochemical eac ions, which dec eases he capaci y o ba e ies. On he con a y, in
he case o 2 A discha ging cu en , he ba e y’s capaci y a 10
◦
C is highe (120%) han a
25
◦
C. The eason is ha he high discha ging cu en h ough he in e nal esis ance o he
ba e y causes high Joule hea ing. While he empe a u e is lowe (10
◦
C), he Joule hea ing
inc eases he in e nal empe a u e and hen also inc eases he e iciency o eac ions. In he
case o 25
◦
C, he in e nal empe a u e was also inc eased by Joule hea ing bu exceeded
he ideal ope a ing empe a u e, and hen caused he decline o capaci y.
Ba e ies 2024, 10, x FOR PEER REVIEW 17 o 30
he ba e y causes high Joule hea ing. While he empe a u e is lowe (10 °C), he Joule
hea ing inc eases he in e nal empe a u e and hen also inc eases he e iciency o eac-
ions. In he case o 25 °C, he in e nal empe a u e was also inc eased by Joule hea ing
bu exceeded he ideal ope a ing empe a u e, and hen caused he decline o capaci y.
(a)
(b)
Figu e 13. Discha ging capaci y o a Lead-acid ba e y a 25 °C and 10 °C: (a) 1 A discha ging cu -
en ; (b) 2 A discha ging cu en .
3.4. Nickel Ba e ies
Ni-Cd ba e ies we e in en ed in he ea ly 20 h cen u y, o elimina e he disad-
an ages o Lead-acid ba e ies, such as deep-discha ging and s o ing in uncha ged s a e
p oblems. Mo eo e , long li e cycles and a wide ange o ope a ing empe a u es a e o he
s ong poin s o Ni-Cd ba e ies. Howe e , hey ha e se e al disad an ages, like highe
cos , lowe powe densi y, and lowe ol age pe cell. The mos c i ical disad an age is
called he “memo y e ec ”, which causes he g adual loss o he ba e y’s maximum en-
e gy capaci y. In ac , Ni-Cd ba e ies ound hei place in a la ge numbe o applica ions,
om powe sou ces o po able elec ical and elec onic de ices o applica ions in ans-
po a ion, a ia ion and e en ae ospace [5,23,26,30,31].
Since he ea ly 21s cen u y, he Ni-Cd ba e ies ha e been g adually phased ou om
applica ion due o he oxici y o Cadmium. The al e na i e selec ion was Ni-MH ba e -
ies, which do no con ain oxic ma e ials. In addi ion, he “memo y e ec ” has al eady
been emo ed in Ni-MH ba e ies, and he powe ene gy densi y o Ni-MH ba e ies is
almos double Ni-Cd ba e ies. The disad an ages, compa ed wi h Ni-Cd ba e ies, a e
highe in e nal esis ance and a signi ican decline in capaci y a low- empe a u e le els
(below 0 °C). The mos c i ical p oblem is he high sel -discha ged cu en , whe e he
s o ed ene gy in a Ni-MH ba e y can be educed o 5–20% on he i s day and a e ha ,
up o 30% pe mon h. In addi ion, he sel -discha ge a e also depends on he capaci y and
empe a u e. In gene al, he la ge he capaci y o he ba e y is, he la ge he sel -dis-
cha ge a e becomes. Ne e heless, he Ni-MH ba e y has been one o he mos used ba -
e y ypes, especially in he EV (elec ic ehicle) and HEV (hyb id elec ic ehicle) indus-
ies. Because o using non- oxic ma e ials, Ni-MH ba e ies ha e also been he mos com-
mon echa geable cylind ical ba e y (AA o AAA ba e ies) o daily and e en eme gency
use in mili a y elec ical and elec onic po able de ices [4,16,19,23,32,33,36–38].
Figu e 14 p esen s he expe imen esul s o measu ing Nickel ba e ies’ discha ge
cha ac e is ics. Measu emen s we e conduc ed a 25 °C on bo h Ni-Cd and Ni-MH ba e -
ies. The cha ac e is ics show highe in e nal esis ance o Ni-MH ba e y in compa ison
wi h Ni-Cd. This cha ac e is ic is one o he c i ical disad an ages o Ni-MH ba e ies
while i hinde s hem om applica ions equi ing high discha ge cu en .
I can also be seen ha he e minal ol age o he Ni-Cd ba e y changed less du ing
he discha ge du a ion. In all he measu emen cases, he quick ol age d op is easily
e ec o
in e nal
esis ance
declining o capaci y
(e ec o empe a u e)
declining o capaci y
(e ec o empe a u e)
Figu e 13. Discha ging capaci y o a Lead-acid ba e y a 25
◦
C and 10
◦
C: (a) 1 A discha ging cu en ;
(b) 2 A discha ging cu en .
3.4. Nickel Ba e ies
Ni-Cd ba e ies we e in en ed in he ea ly 20 h cen u y, o elimina e he disad an ages
o Lead-acid ba e ies, such as deep-discha ging and s o ing in uncha ged s a e p oblems.
Mo eo e , long li e cycles and a wide ange o ope a ing empe a u es a e o he s ong
poin s o Ni-Cd ba e ies. Howe e , hey ha e se e al disad an ages, like highe cos ,
lowe powe densi y, and lowe ol age pe cell. The mos c i ical disad an age is called

Ba e ies 2024,10, 43 17 o 29
he “memo y e ec ”, which causes he g adual loss o he ba e y’s maximum ene gy
capaci y. In ac , Ni-Cd ba e ies ound hei place in a la ge numbe o applica ions, om
powe sou ces o po able elec ical and elec onic de ices o applica ions in anspo a ion,
a ia ion and e en ae ospace [5,23,26,30,31].
Since he ea ly 21s cen u y, he Ni-Cd ba e ies ha e been g adually phased ou om
applica ion due o he oxici y o Cadmium. The al e na i e selec ion was Ni-MH ba e ies,
which do no con ain oxic ma e ials. In addi ion, he “memo y e ec ” has al eady been
emo ed in Ni-MH ba e ies, and he powe ene gy densi y o Ni-MH ba e ies is almos
double Ni-Cd ba e ies. The disad an ages, compa ed wi h Ni-Cd ba e ies, a e highe
in e nal esis ance and a signi ican decline in capaci y a low- empe a u e le els (below
0
◦
C). The mos c i ical p oblem is he high sel -discha ged cu en , whe e he s o ed ene gy
in a Ni-MH ba e y can be educed o 5–20% on he i s day and a e ha , up o 30% pe
mon h. In addi ion, he sel -discha ge a e also depends on he capaci y and empe a u e.
In gene al, he la ge he capaci y o he ba e y is, he la ge he sel -discha ge a e becomes.
Ne e heless, he Ni-MH ba e y has been one o he mos used ba e y ypes, especially in
he EV (elec ic ehicle) and HEV (hyb id elec ic ehicle) indus ies. Because o using non-
oxic ma e ials, Ni-MH ba e ies ha e also been he mos common echa geable cylind ical
ba e y (AA o AAA ba e ies) o daily and e en eme gency use in mili a y elec ical and
elec onic po able de ices [4,16,19,23,32,33,36–38].
Figu e 14 p esen s he expe imen esul s o measu ing Nickel ba e ies’ discha ge
cha ac e is ics. Measu emen s we e conduc ed a 25
◦
C on bo h Ni-Cd and Ni-MH ba e ies.
The cha ac e is ics show highe in e nal esis ance o Ni-MH ba e y in compa ison wi h
Ni-Cd. This cha ac e is ic is one o he c i ical disad an ages o Ni-MH ba e ies while i
hinde s hem om applica ions equi ing high discha ge cu en .
Ba e ies 2024, 10, x FOR PEER REVIEW 18 o 30
ound a he end o he discha ge p ocess, which can be a use ul e ec o es ima ing he
SoC (s a e o cha ge) o DoD (Dep h o Discha ge) o ba e ies in ope a ion.
(a)
(b)
Figu e 14. Discha ge cha ac e is ic a 25 °C: (a) Ni-Cd ba e y; (b) Ni-MH ba e y.
Figu e 15 shows he esul s o ano he expe imen , whe e he cha ge and discha ge
cha ac e is ics o Ni-MH we e moni o ed a di e en empe a u es while he cha ge and
discha ge cu en we e kep cons an a 1 A. Expe imen s we e conduc ed a 25 °C, 10 °C,
and −10 °C. The d ama ic decline o capaci y a nega i e empe a u e is clea ly p esen ed.
In discha ging du a ion, he es ed Ni-MH ba e y was able o discha ge only abou 20%
s o ed ene gy, in compa ison o discha ged ene gy a 10 °C and 25 °C. In cha ging du a-
ion, his decline is e en mo e signi ican . E en hough he ba e y ol age eaches he
highe alue a −10 °C, only o e 10% capaci y o he ba e y was cha ged, in compa ison
o he cha ged capaci y a 10 °C and 25 °C.
Figu e 15a also p esen s he dependence o Ni-MH ba e ies’ in e nal esis ance on
empe a u e. In he case o cons an discha ge ol age, he in e nal esis ance gene ally
inc eases wi h he dec ease in ope a ing empe a u e.
Figu e 15. Cha ac e is ics and capaci y o Nickel ba e ies a 25 °C, 10 °C, and −10 °C: (a) Ni-MH
ba e y discha ging a 1 A; (b) Ni-MH ba e y cha ging a 1 A.
3.5. Li hium-Ion Ba e ies
Li hium is he ba e y echnology nowadays, appea ing in a huge amoun o applica-
ions. Li hium is he ligh es me al and he leas dense solid elemen , making li hium ba -
e ies ake ad an age o ligh weigh , high ene gy, and powe densi y. The ene gy and
powe densi y o li hium ba e ies can be i e imes g ea e han Lead-acid o Ni-Cd
e ec o
in e nal
esis ance
e ec o
in e nal
esis ance
Quick ol age d op
Quick ol age d op
e ec o
discha ge cu en
e ec o
discha ge cu en
Figu e 14. Discha ge cha ac e is ic a 25 ◦C: (a) Ni-Cd ba e y; (b) Ni-MH ba e y.
I can also be seen ha he e minal ol age o he Ni-Cd ba e y changed less du ing
he discha ge du a ion. In all he measu emen cases, he quick ol age d op is easily ound
a he end o he discha ge p ocess, which can be a use ul e ec o es ima ing he SoC
(s a e o cha ge) o DoD (Dep h o Discha ge) o ba e ies in ope a ion.
Figu e 15 shows he esul s o ano he expe imen , whe e he cha ge and discha ge
cha ac e is ics o Ni-MH we e moni o ed a di e en empe a u es while he cha ge and
discha ge cu en we e kep cons an a 1 A. Expe imen s we e conduc ed a 25
◦
C, 10
◦
C,
and
−
10
◦
C. The d ama ic decline o capaci y a nega i e empe a u e is clea ly p esen ed.
In discha ging du a ion, he es ed Ni-MH ba e y was able o discha ge only abou 20%
s o ed ene gy, in compa ison o discha ged ene gy a 10
◦
C and 25
◦
C. In cha ging du a ion,
his decline is e en mo e signi ican . E en hough he ba e y ol age eaches he highe
alue a
−
10
◦
C, only o e 10% capaci y o he ba e y was cha ged, in compa ison o he
cha ged capaci y a 10 ◦C and 25 ◦C.
Ba e ies 2024,10, 43 18 o 29
Ba e ies 2024, 10, x FOR PEER REVIEW 18 o 30
ound a he end o he discha ge p ocess, which can be a use ul effec o es ima ing he
SoC (s a e o cha ge) o DoD (Dep h o Discha ge) o ba e ies in ope a ion.
(a) (b)
Figu e 14. Discha ge cha ac e is ic a 25 °C: (a) Ni-Cd ba e y; (b) Ni-MH ba e y.
Figu e 15 shows he esul s o ano he expe imen , whe e he cha ge and discha ge
cha ac e is ics o Ni-MH we e moni o ed a diffe en empe a u es while he cha ge and
discha ge cu en we e kep cons an a 1 A. Expe imen s we e conduc ed a 25 °C, 10 °C,
and −10 °C. The d ama ic decline o capaci y a nega i e empe a u e is clea ly p esen ed.
In discha ging du a ion, he es ed Ni-MH ba e y was able o discha ge only abou 20%
s o ed ene gy, in compa ison o discha ged ene gy a 10 °C and 25 °C. In cha ging du a-
ion, his decline is e en mo e signi ican . E en hough he ba e y ol age eaches he
highe alue a −10 °C, only o e 10% capaci y o he ba e y was cha ged, in compa ison
o he cha ged capaci y a 10 °C and 25 °C.
Figu e 15a also p esen s he dependence o Ni-MH ba e ies’ in e nal esis ance on
empe a u e. In he case o cons an discha ge ol age, he in e nal esis ance gene ally
inc eases wi h he dec ease in ope a ing empe a u e.
Figu e 15. Cha ac e is ics and capaci y o Nickel ba e ies a 25 °C, 10 °C, and −10 °C: (a) Ni-MH
ba e y discha ging a 1 A; (b) Ni-MH ba e y cha ging a 1 A.
3.5. Li hium-Ion Ba e ies
Li hium is he ba e y echnology nowadays, appea ing in a huge amoun o applica-
ions. Li hium is he ligh es me al and he leas dense solid elemen , making li hium ba -
e ies ake ad an age o ligh weigh , high ene gy, and powe densi y. The ene gy and
powe densi y o li hium ba e ies can be i e imes g ea e han Lead-acid o Ni-Cd
100101102103104105
Discha ge du a ion [s]
9
9.5
10
10.5
11
11.5
12
12.5
13
Disch age cha ac e is ic a 25°C - Ni-Cd ba e y
1A-25°C
5A-25°C
10A-25°C
100101102103104105106107
Discha ge du a ion [s]
5
6
7
8
9
10
11
12
Disch age cha ac e is ic a 25°C - Ni-MH ba e y
1A-25°C
5A-25°C
10A-25°C
e ec o
in e nal
esis ance
e ec o
in e nal
esis ance
Quick ol age d op Quick ol age d op
e ec o
discha ge cu en
e ec o
discha ge cu en
Figu e 15. Cha ac e is ics and capaci y o Nickel ba e ies a 25
◦
C, 10
◦
C, and
−
10
◦
C: (a) Ni-MH
ba e y discha ging a 1 A; (b) Ni-MH ba e y cha ging a 1 A.
Figu e 15a also p esen s he dependence o Ni-MH ba e ies’ in e nal esis ance on
empe a u e. In he case o cons an discha ge ol age, he in e nal esis ance gene ally
inc eases wi h he dec ease in ope a ing empe a u e.
3.5. Li hium-Ion Ba e ies
Li hium is he ba e y echnology nowadays, appea ing in a huge amoun o applica ions.
Li hium is he ligh es me al and he leas dense solid elemen , making li hium ba e ies ake
ad an age o ligh weigh , high ene gy, and powe densi y. The ene gy and powe densi y o
li hium ba e ies can be i e imes g ea e han Lead-acid o Ni-Cd ba e ies. Li hium ba e ies’
ol age pe cell is also highe (3.0 V–4.2 V) in compa ison wi h o he ypes, e.g., Lead-acid
ba e ies (1.8 V–2.1 V) and Nickel ba e ies (0.85 V–1.35 V) [3–7,16,20,21,27,29,39,40].
The mos common li hium ba e y ype is he Li-ion (li hium-ion) ba e y. In his ype,
li hium is used in compound o ms, which dec eases he haza d o li hium disposi ion.
O he ad an ages o Li-ion a e hei smalle sel -discha ging a e and much longe li e
cycle han o he ypes o echa geable ba e ies. On he o he hand, Li-ion is a qui e
dange ous ba e y ype. The abili y o discha ge a a high a e makes i a high isk o
combus ion and explosion. O he p oblems, o e -cha ging, o e -discha ging, o e cu en ,
and he mal issues, signi ican ly a ec he li e cycle and sa e y o Li-ion ba e ies. To esol e
hese issues, a BMS (Ba e y Managemen Sys em) is usually equi ed by sys ems using
Li-ion ba e ies [
3
–
7
,
16
,
20
,
21
,
27
,
29
,
39
–
48
]. I ollows om he abo e, BMS manages he
echa geable ba e y (cell o ba e y pack), p o ec s he ba e y om ope a ing ou side i s
pa ame e s, manages sa e ope a ing, moni o s ba e y s a e, compu es seconda y da a like
he minimum and maximum ol age, s a e o cha ge, s a e o heal h, con olling ba e y
en i onmen , au hen ica ing i and balancing cells in a ba e y pack, e c. BMS also epo s
da a ia he a ailable communica ion po s o he HMI in e ace in an app op ia e way.
The BMS is an in eg al pa o he Li-ion ba e y (applica ion) and mus be add essed.
Thanks o he abo e-men ioned bene i s, li hium ba e ies ha e become he winne
in almos all applica ions. I is easy o name a la ge numbe o ou daily de ices using
li hium ba e ies, e.g., mobile phones, able s, lap ops, and many o he po able elec ical
and elec onic de ices. Likewise, in anspo a ion, li hium ba e ies a e also common in
he HEV and EV indus y, in buses, locomo i es, and a ia ion. In ecen yea s, li hium
ba e ies ha e also been used as ene gy s o age solu ions o HRES (Hyb id Renewable
Ene gy Sys ems) due o inc easing conce ns abou hese sys ems.
In mili a y applica ions, li hium ba e ies ha e been he bes solu ion o dismoun ed
soldie sys ems because o hei ligh weigh , small size, and high capaci y. The apid
inc eases in using small UVs (unmanned ehicles) in he mili a y also make li hium ba e ies
mo e impo an . The small UVs powe supply is sol ed using li hium ba e ies o sa e
he o al weigh and gua an ee a good powe supply. Li hium ba e ies ha e also been
Ba e ies 2024,10, 43 19 o 29
used as he powe sou ce and UPS o ada sys ems o elec onic wa a e equipmen .
In many coun ies, he e is also a end o eplacing Lead-acid and Nickel ba e ies used
in mili a y anspo a ion and comba ehicles wi h li hium ba e ies. In he nea u u e,
hyb id elec ic ehicles, o e en ully elec ic ehicles using li hium ba e ies, ha e a big
po en ial o become he s anda d anspo a ion and comba ehicles in many mili a ies.
To expe imen ally analyze he p ope ies o li hium ba e ies, se e al measu emen s
we e conduc ed. The es ed Li-ion ba e y was discha ged a di e en empe a u es
wi h di e en discha ging cu en s. The selec ed expe imen al empe a u es we e 25
◦
C,
10
◦
C, and
−
10
◦
C; he selec ed es ed discha ging cu en s we e 1 A and 2 A. Expe imen al
esul s a e g aphically p esen ed in Figu es 16 and 17 wi h a b ie analysis.
Ba e ies 2024, 10, x FOR PEER REVIEW 20 o 30
(a)
(b)
Figu e 16. Discha ge cha ac e is ics and capaci y o Li-ion ba e y discha ging a 1 A, 2 A, and 4 A:
(a) a empe a u e 25 °C; (b) a empe a u e 10 °C.
Figu e 17 p esen s he dependence o in e nal esis ance on empe a u e. A he con-
s an discha ge cu en , he in e nal esis ance gene ally inc eases wi h he dec ease in
empe a u e. In low empe a u es and high discha ge cu en , i can be seen he apid
ol age d op—see Figu e 17b. This cha ac e is ic can be c i ical o such applica ions e-
qui ing smoo h supply ol age. I is also clea ha empe a u e has a huge e ec on he
ba e y’s capaci y. The capaci y can be educed o hal when he empe a u e d ops, espe-
cially a minus empe a u es—see Figu e 17a. The eason is ha he e ec i i y o in e nal
elec ochemical eac ions is lowe a lowe empe a u es.
Figu e 17b con ains an in e es ing phenomenon, ha capaci y a −10 °C is nea ly he
capaci y a 25 °C much be e han a 10 °C. The eason is ha in e nal esis ance inc eases
a minus empe a u es, causing he inc ease o Joule hea ing, which inc eases he in e nal
empe a u e o he ba e y and imp o es he e ec i i y o in e nal elec ochemical eac-
ions.
(a)
(b)
Figu e 17. Discha ge cha ac e is ics and capaci y o Li-ion ba e y a empe a u es 25 °C, 10 °C, and
−10 °C: (a) wi h discha ging cu en 1 A; (b) wi h discha ging cu en 2 A.
The e o e, i can be seen om he s a ed esul s, and when compa ing cha ac e is ics
in Figu es 13, 15 and 17, ha he mos s iking e ec is o he echnology wi h Ni-Cd. Fo
he sake o in e es , compa e he esul s o he beha io o supe capaci o s. Supe capaci o
beha io as shown below, whe e he e ec o empe a u e is almos in isible (see he e-
sul s in Sec ion 3.6).
in e nal esis ance
depends on
empe a u e
Rapid ol age d op
e ec o
in e nal
esis ance
e ec o
in e nal
esis ance
Capaci y less depends
on discha ge cu en
Capaci y less depends
on discha ge cu en
declining o capaci y
(e ec o empe a u e)
declining o capaci y
(e ec o empe a u e)
Figu e 16. Discha ge cha ac e is ics and capaci y o Li-ion ba e y discha ging a 1 A, 2 A, and 4 A:
(a) a empe a u e 25 ◦C; (b) a empe a u e 10 ◦C.
Ba e ies 2024, 10, x FOR PEER REVIEW 20 o 30
(a)
(b)
Figu e 16. Discha ge cha ac e is ics and capaci y o Li-ion ba e y discha ging a 1 A, 2 A, and 4 A:
(a) a empe a u e 25 °C; (b) a empe a u e 10 °C.
Figu e 17 p esen s he dependence o in e nal esis ance on empe a u e. A he con-
s an discha ge cu en , he in e nal esis ance gene ally inc eases wi h he dec ease in
empe a u e. In low empe a u es and high discha ge cu en , i can be seen he apid
ol age d op—see Figu e 17b. This cha ac e is ic can be c i ical o such applica ions e-
qui ing smoo h supply ol age. I is also clea ha empe a u e has a huge e ec on he
ba e y’s capaci y. The capaci y can be educed o hal when he empe a u e d ops, espe-
cially a minus empe a u es—see Figu e 17a. The eason is ha he e ec i i y o in e nal
elec ochemical eac ions is lowe a lowe empe a u es.
Figu e 17b con ains an in e es ing phenomenon, ha capaci y a −10 °C is nea ly he
capaci y a 25 °C much be e han a 10 °C. The eason is ha in e nal esis ance inc eases
a minus empe a u es, causing he inc ease o Joule hea ing, which inc eases he in e nal
empe a u e o he ba e y and imp o es he e ec i i y o in e nal elec ochemical eac-
ions.
(a)
(b)
Figu e 17. Discha ge cha ac e is ics and capaci y o Li-ion ba e y a empe a u es 25 °C, 10 °C, and
−10 °C: (a) wi h discha ging cu en 1 A; (b) wi h discha ging cu en 2 A.
The e o e, i can be seen om he s a ed esul s, and when compa ing cha ac e is ics
in Figu es 13, 15 and 17, ha he mos s iking e ec is o he echnology wi h Ni-Cd. Fo
he sake o in e es , compa e he esul s o he beha io o supe capaci o s. Supe capaci o
beha io as shown below, whe e he e ec o empe a u e is almos in isible (see he e-
sul s in Sec ion 3.6).
in e nal esis ance
depends on
empe a u e
Rapid ol age d op
e ec o
in e nal
esis ance
e ec o
in e nal
esis ance
Capaci y less depends
on discha ge cu en
Capaci y less depends
on discha ge cu en
declining o capaci y
(e ec o empe a u e)
declining o capaci y
(e ec o empe a u e)
Figu e 17. Discha ge cha ac e is ics and capaci y o Li-ion ba e y a empe a u es 25
◦
C, 10
◦
C, and
−10 ◦C: (a) wi h discha ging cu en 1 A; (b) wi h discha ging cu en 2 A.
Figu e 16 shows he e ec o in e nal esis ance on discha ge cha ac e is ics, which
causes a dec ease in e minal ol age while he discha ge cu en inc eases. The measu e-
men esul s also show ha he capaci y o Li-ion depends less on he discha ge cu en . A
he cons an empe a u e le el, he discha ged capaci ies a di e en discha ging cu en s
a e di e en , only less han 10%.
Figu e 17 p esen s he dependence o in e nal esis ance on empe a u e. A he
cons an discha ge cu en , he in e nal esis ance gene ally inc eases wi h he dec ease
in empe a u e. In low empe a u es and high discha ge cu en , i can be seen he apid
ol age d op—see Figu e 17b. This cha ac e is ic can be c i ical o such applica ions
equi ing smoo h supply ol age. I is also clea ha empe a u e has a huge e ec on
Ba e ies 2024,10, 43 20 o 29
he ba e y’s capaci y. The capaci y can be educed o hal when he empe a u e d ops,
especially a minus empe a u es—see Figu e 17a. The eason is ha he e ec i i y o
in e nal elec ochemical eac ions is lowe a lowe empe a u es.
Figu e 17b con ains an in e es ing phenomenon, ha capaci y a
−
10
◦
C is nea ly he
capaci y a 25
◦
C much be e han a 10
◦
C. The eason is ha in e nal esis ance inc eases
a minus empe a u es, causing he inc ease o Joule hea ing, which inc eases he in e nal
empe a u e o he ba e y and imp o es he e ec i i y o in e nal elec ochemical eac ions.
The e o e, i can be seen om he s a ed esul s, and when compa ing cha ac e is ics
in Figu es 13,15 and 17, ha he mos s iking e ec is o he echnology wi h Ni-Cd. Fo
he sake o in e es , compa e he esul s o he beha io o supe capaci o s. Supe capaci o
beha io as shown below, whe e he e ec o empe a u e is almos in isible (see he esul s
in Sec ion 3.6).
3.6. Pa ial Conclusion
Figu e 18a p esen s he compa ison o selec ed ba e y echnologies based on he
main cha ac e s—se ice li e, cha ging e iciency, powe densi y, and ene gy densi y. The
compa ison shows he ou s anding ad an ages o Li-ion echnology, which is he mos
ad an ageous echnology in almos all c i e ia. Ni-Cd has a sligh ly be e se ice li e, bu
i s oxici y and he equi emen s o s ic ly sui able use o a oid he memo y e ec dec ease
he Ni-Cd ba e y’s se ice li e.
Ba e ies 2024, 10, x FOR PEER REVIEW 21 o 30
3.6. Pa ial Conclusion
Figu e 18a p esen s he compa ison o selec ed ba e y echnologies based on he
main cha ac e s—se ice li e, cha ging e iciency, powe densi y, and ene gy densi y. The
compa ison shows he ou s anding ad an ages o Li-ion echnology, which is he mos
ad an ageous echnology in almos all c i e ia. Ni-Cd has a sligh ly be e se ice li e, bu
i s oxici y and he equi emen s o s ic ly sui able use o a oid he memo y e ec de-
c ease he Ni-Cd ba e y’s se ice li e.
Figu e 18b shows he compa ison be ween he cu en comme cially a ailable Li-ion
polyme ba e y pack and Lead-acid ba e y pack. I is ob ious ha he pa ame e s o he
Li-ion ba e y pack a e much be e han he Lead-acid ba e y. Al hough he dimensions
and he weigh o he Lead-acid ba e y a e one and a hal imes bigge han he Li-ion
polyme ba e y pack, he powe s o ed in he Lead-acid ba e y is only hal o Li-ion. The
ou pu ol age o he Li-ion ba e y pack is also h ee imes highe han Lead-acid, making
i sui able o applica ions equi ing an elec ical sou ce wi h highe ol age.
Ne e heless, his compa ison lacks a p ice c i e ion, in which he Lead-acid ba e y
is he winne . Fo his eason, Lead-acid, he oldes ype o ba e y, s ill has i s own im-
po an ole in se e al applica ions, o example, SLI sys ems in au omo i e o UPS sys-
ems o mili a y ada s a ions. The Ni-MH ba e y is also a good selec ion o applica-
ions ha do no equi e high powe densi y and ene gy densi y, o example, ixed UPS
s a ions o HRES sys ems.
Figu e 18. Ba e y compa ison: (a) based on heo e ical main cha ac e is ics [3–5,16,21]; (b) be ween
cu en ly comme cially a ailable Li-ion polyme ba e y and Lead-acid ba e y.
The compa ison be ween Li-ion ba e ies and supe capaci o s is shown in Figu e 19.
The powe densi y o he supe capaci o is much highe han he Li-ion ba e y. The se -
ice li e o supe capaci o s is also an ou s anding ad an age because supe capaci o s op-
e a e wi hou any elec ochemical eac ion o changes in ma e ials. The cha ging e icien-
cies o Li-ion ba e ies and supe capaci o s a e simila and highe han o he ba e y ypes,
making hem he mos common solu ion o ene gy s o age. The mos signi ican weak-
ness o supe capaci o s is hei ene gy densi y, which is limi ed by hei capaci ance and
maximum ol age. In con as , ba e ies ha e be e ene gy densi y.
(b)
(a)
Figu e 18. Ba e y compa ison: (a) based on heo e ical main cha ac e is ics [
3
–
5
,
16
,
21
]; (b) be ween
cu en ly comme cially a ailable Li-ion polyme ba e y and Lead-acid ba e y.
Figu e 18b shows he compa ison be ween he cu en comme cially a ailable Li-ion
polyme ba e y pack and Lead-acid ba e y pack. I is ob ious ha he pa ame e s o he
Li-ion ba e y pack a e much be e han he Lead-acid ba e y. Al hough he dimensions
and he weigh o he Lead-acid ba e y a e one and a hal imes bigge han he Li-ion
polyme ba e y pack, he powe s o ed in he Lead-acid ba e y is only hal o Li-ion. The
ou pu ol age o he Li-ion ba e y pack is also h ee imes highe han Lead-acid, making
i sui able o applica ions equi ing an elec ical sou ce wi h highe ol age.
Ne e heless, his compa ison lacks a p ice c i e ion, in which he Lead-acid ba e y is
he winne . Fo his eason, Lead-acid, he oldes ype o ba e y, s ill has i s own impo an
Ba e ies 2024,10, 43 21 o 29
ole in se e al applica ions, o example, SLI sys ems in au omo i e o UPS sys ems o
mili a y ada s a ions. The Ni-MH ba e y is also a good selec ion o applica ions ha
do no equi e high powe densi y and ene gy densi y, o example, ixed UPS s a ions o
HRES sys ems.
The compa ison be ween Li-ion ba e ies and supe capaci o s is shown in Figu e 19.
The powe densi y o he supe capaci o is much highe han he Li-ion ba e y. The se ice
li e o supe capaci o s is also an ou s anding ad an age because supe capaci o s ope a e
wi hou any elec ochemical eac ion o changes in ma e ials. The cha ging e iciencies o
Li-ion ba e ies and supe capaci o s a e simila and highe han o he ba e y ypes, making
hem he mos common solu ion o ene gy s o age. The mos signi ican weakness o
supe capaci o s is hei ene gy densi y, which is limi ed by hei capaci ance and maximum
ol age. In con as , ba e ies ha e be e ene gy densi y.
Ba e ies 2024, 10, x FOR PEER REVIEW 22 o 30
Figu e 19. Compa ison be ween Li-ion ba e y and supe capaci o .
The compa ison be ween Li-ion ba e ies and PEM Fuel Cells is shown in Figu e 20.
Because Li-ion ba e ies can p o ide a highe cu en and a highe ou pu ol age, he
powe densi y o Li-ion ba e ies is highe han PEM FCs. The cha ging e iciencies o Li-
ion ba e ies and PEM FCs a e simila and also simila o supe capaci o s’ cha ging e i-
ciency. As men ioned abo e, he mos signi ican weakness o supe capaci o s is hei en-
e gy densi y, which is, in con as , he mos impo an ad an age o PEM FCs, while he
ene gy is s o ed in he o m o hyd ogen and oxygen.
Figu e 20. Compa ison be ween Li-ion ba e y and PEM Fuel Cell.
Fo mili a y applica ions, i is impo an o s udy he ope a ing empe a u e ange o
each echnology. The compa ison is shown in Figu e 21. In common, compa ed wi h o he
ba e y ypes, he Ni-Cd ba e y and Li-ion ba e y a e he bes ba e y echnology in he
c i e ia o ope a ing empe a u e ange, as hey can ope a e in bo h deepe nega i e em-
pe a u es and highe posi i e empe a u es. The e o e, Ni-Cd has s ill been he solu ion
o a numbe o applica ions wi h c i ical ope a ing empe a u es, o example, in ae o-
space and a ia ion applica ions. In hese applica ions, he o he Nickel ba e y ype—
NiMH ba e y, canno be used because i is no able o ope a e in nega i e empe a u es
(as men ioned abo e, i s capaci y meaning ully dec eases in nega i e empe a u es).
Figu e 19. Compa ison be ween Li-ion ba e y and supe capaci o .
The compa ison be ween Li-ion ba e ies and PEM Fuel Cells is shown in Figu e 20.
Because Li-ion ba e ies can p o ide a highe cu en and a highe ou pu ol age, he
powe densi y o Li-ion ba e ies is highe han PEM FCs. The cha ging e iciencies o
Li-ion ba e ies and PEM FCs a e simila and also simila o supe capaci o s’ cha ging
e iciency. As men ioned abo e, he mos signi ican weakness o supe capaci o s is hei
ene gy densi y, which is, in con as , he mos impo an ad an age o PEM FCs, while he
ene gy is s o ed in he o m o hyd ogen and oxygen.
Fo mili a y applica ions, i is impo an o s udy he ope a ing empe a u e ange
o each echnology. The compa ison is shown in Figu e 21. In common, compa ed wi h
o he ba e y ypes, he Ni-Cd ba e y and Li-ion ba e y a e he bes ba e y echnology in
he c i e ia o ope a ing empe a u e ange, as hey can ope a e in bo h deepe nega i e
empe a u es and highe posi i e empe a u es. The e o e, Ni-Cd has s ill been he solu ion
o a numbe o applica ions wi h c i ical ope a ing empe a u es, o example, in ae ospace
and a ia ion applica ions. In hese applica ions, he o he Nickel ba e y ype—NiMH
ba e y, canno be used because i is no able o ope a e in nega i e empe a u es (as
men ioned abo e, i s capaci y meaning ully dec eases in nega i e empe a u es).

Ba e ies 2024,10, 43 22 o 29
Ba e ies 2024, 10, x FOR PEER REVIEW 22 o 30
Figu e 19. Compa ison be ween Li-ion ba e y and supe capaci o .
The compa ison be ween Li-ion ba e ies and PEM Fuel Cells is shown in Figu e 20.
Because Li-ion ba e ies can p o ide a highe cu en and a highe ou pu ol age, he
powe densi y o Li-ion ba e ies is highe han PEM FCs. The cha ging e iciencies o Li-
ion ba e ies and PEM FCs a e simila and also simila o supe capaci o s’ cha ging e i-
ciency. As men ioned abo e, he mos signi ican weakness o supe capaci o s is hei en-
e gy densi y, which is, in con as , he mos impo an ad an age o PEM FCs, while he
ene gy is s o ed in he o m o hyd ogen and oxygen.
Figu e 20. Compa ison be ween Li-ion ba e y and PEM Fuel Cell.
Fo mili a y applica ions, i is impo an o s udy he ope a ing empe a u e ange o
each echnology. The compa ison is shown in Figu e 21. In common, compa ed wi h o he
ba e y ypes, he Ni-Cd ba e y and Li-ion ba e y a e he bes ba e y echnology in he
c i e ia o ope a ing empe a u e ange, as hey can ope a e in bo h deepe nega i e em-
pe a u es and highe posi i e empe a u es. The e o e, Ni-Cd has s ill been he solu ion
o a numbe o applica ions wi h c i ical ope a ing empe a u es, o example, in ae o-
space and a ia ion applica ions. In hese applica ions, he o he Nickel ba e y ype—
NiMH ba e y, canno be used because i is no able o ope a e in nega i e empe a u es
(as men ioned abo e, i s capaci y meaning ully dec eases in nega i e empe a u es).
Figu e 20. Compa ison be ween Li-ion ba e y and PEM Fuel Cell.
Ba e ies 2024, 10, x FOR PEER REVIEW 23 o 30
Figu e 21. Ope a ing empe a u e ange o each echnology.
The PEM FCs ha e he simila ba ie o NiMH ba e ies, ha hey ha e no abili y o
ope a e in nega i e empe a u es. In addi ion, cha ac e is ics o PEM FCs a low-posi i e
empe a u es a e also e y poo —see Figu e 21. The winne in his c i e ion is supe ca-
paci o s. Thei ope a ing p inciple is elec ically-based so ha hey can ope a e om e y
deep nega i e empe a u es o e y high posi i e empe a u es.
Ou side o hese compa isons, he cu en bigges ba ie o ba e y echnologies is
he discha ging cu en limi . O e cha ging can cause se e al c i ical issues, such as o e -
hea ing ha nega i ely affec s he ba e y’s hea h o leads o combus ion and explosion in
he mos dange ous cases. In he case o FCs, hei slow dynamics a e hei own d awback.
Ba e ies ha e be e dynamics; howe e , he bes solu ion o applica ions equi ing dy-
namic beha io s is a supe capaci o . The e o e, i is bene icial o combine ba e ies wi h
Fuel Cells and supe capaci o s in he hyb id powe sou ce (HPS) sys em o elimina e he
disad an ages o each by using he ad an ages o o he s. Supe capaci o s a e capable o
discha ging e y high cu en s and p o ide e y as esponse bu ha e limi ed capaci y.
In con as , he ba e y and FCs ha e a highe capaci y, bu he maximum sa e discha ge
cu en and he a e o esponse is limi ed. The ypical p oposed HPS opology o elec i-
cal and hyb id de ices is shown in Figu e 22.
I can be seen ha Figu e 22 p esen s an HPS sys em wi h a h ee-phase in e e con-
e ing DC ol age om DC bus o AC ol age o h ee-phase sys ems. In common ap-
plica ions, he h ee-phase sys em is he mos ypical. Howe e , in special applica ions,
o example, in mili a y applica ions, as in ou case, he i e-phase sys em is also used. In
his case, he in e e opology can be modi ied by adding wo mo e b idges.
Figu e 21. Ope a ing empe a u e ange o each echnology.
The PEM FCs ha e he simila ba ie o NiMH ba e ies, ha hey ha e no abili y o
ope a e in nega i e empe a u es. In addi ion, cha ac e is ics o PEM FCs a low-posi i e
empe a u es a e also e y poo —see Figu e 21. The winne in his c i e ion is supe capaci-
o s. Thei ope a ing p inciple is elec ically-based so ha hey can ope a e om e y deep
nega i e empe a u es o e y high posi i e empe a u es.
Ou side o hese compa isons, he cu en bigges ba ie o ba e y echnologies
is he discha ging cu en limi . O e cha ging can cause se e al c i ical issues, such as
o e hea ing ha nega i ely a ec s he ba e y’s hea h o leads o combus ion and explosion
in he mos dange ous cases. In he case o FCs, hei slow dynamics a e hei own
d awback. Ba e ies ha e be e dynamics; howe e , he bes solu ion o applica ions
equi ing dynamic beha io s is a supe capaci o . The e o e, i is bene icial o combine
ba e ies wi h Fuel Cells and supe capaci o s in he hyb id powe sou ce (HPS) sys em o
elimina e he disad an ages o each by using he ad an ages o o he s. Supe capaci o s a e
capable o discha ging e y high cu en s and p o ide e y as esponse bu ha e limi ed
capaci y. In con as , he ba e y and FCs ha e a highe capaci y, bu he maximum sa e
discha ge cu en and he a e o esponse is limi ed. The ypical p oposed HPS opology
o elec ical and hyb id de ices is shown in Figu e 22.
Ba e ies 2024,10, 43 23 o 29
Ba e ies 2024, 10, x FOR PEER REVIEW 24 o 30
Figu e 22. Typical p oposed HPS opology [49].
As men ioned in Sec ion 1, i is a o able o use he supe capaci o as an ene gy buffe
o a ba e ies-based powe sou ce—see Figu e 23. Supe capaci o s’ abili y o cha ge/dis-
cha ge high cu en s and hei high cha ge/discha ge efficiency help o sa e he cos and
he weigh o ehicles, as huge ba e y packs a e no equi ed o high cu en cha ge/dis-
cha ge, o example, when ehicles slow down o accele a e. In case o slowdown, he
egene a ed ene gies in he o m o high elec ical pulses can be s o ed in supe capaci o s
and hen can be used o cha ge he ba e ies wi h a sui able cu en .
Figu e 23. Supe capaci o as ene gy buffe [10].
Ano he ad an age o supe capaci o s is s o age efficiency o supe capaci o s de-
pends less on ope a ing empe a u e because i is elec ical s o age (ins ead o
Figu e 22. Typical p oposed HPS opology [49].
I can be seen ha Figu e 22 p esen s an HPS sys em wi h a h ee-phase in e e
con e ing DC ol age om DC bus o AC ol age o h ee-phase sys ems. In common
applica ions, he h ee-phase sys em is he mos ypical. Howe e , in special applica ions,
o example, in mili a y applica ions, as in ou case, he i e-phase sys em is also used. In
his case, he in e e opology can be modi ied by adding wo mo e b idges.
As men ioned in Sec ion 1, i is a o able o use he supe capaci o as an ene gy
bu e o a ba e ies-based powe sou ce—see Figu e 23. Supe capaci o s’ abili y o
cha ge/discha ge high cu en s and hei high cha ge/discha ge e iciency help o sa e
he cos and he weigh o ehicles, as huge ba e y packs a e no equi ed o high cu -
en cha ge/discha ge, o example, when ehicles slow down o accele a e. In case o
slowdown, he egene a ed ene gies in he o m o high elec ical pulses can be s o ed in
supe capaci o s and hen can be used o cha ge he ba e ies wi h a sui able cu en .
Ba e ies 2024, 10, x FOR PEER REVIEW 24 o 30
Figu e 22. Typical p oposed HPS opology [49].
As men ioned in Sec ion 1, i is a o able o use he supe capaci o as an ene gy buffe
o a ba e ies-based powe sou ce—see Figu e 23. Supe capaci o s’ abili y o cha ge/dis-
cha ge high cu en s and hei high cha ge/discha ge efficiency help o sa e he cos and
he weigh o ehicles, as huge ba e y packs a e no equi ed o high cu en cha ge/dis-
cha ge, o example, when ehicles slow down o accele a e. In case o slowdown, he
egene a ed ene gies in he o m o high elec ical pulses can be s o ed in supe capaci o s
and hen can be used o cha ge he ba e ies wi h a sui able cu en .
Figu e 23. Supe capaci o as ene gy buffe [10].
Ano he ad an age o supe capaci o s is s o age efficiency o supe capaci o s de-
pends less on ope a ing empe a u e because i is elec ical s o age (ins ead o
Figu e 23. Supe capaci o as ene gy bu e [10].
Ba e ies 2024,10, 43 24 o 29
Ano he ad an age o supe capaci o s is s o age e iciency o supe capaci o s depends
less on ope a ing empe a u e because i is elec ical s o age (ins ead o elec ochemical)—
see Figu e 24. The expe imen ally e i ied cha ac e is ics and capaci y o supe capaci o s
a 10
◦
C and
−
10
◦
C a e almos simila . The e ec o discha ging cu en is also small, ci ca
10%.
Ba e ies 2024, 10, x FOR PEER REVIEW 25 o 30
elec ochemical)—see Figu e 24. The expe imen ally e i ied cha ac e is ics and capaci y
o supe capaci o s a 10 °C and −10 °C a e almos simila . The e ec o discha ging cu en
is also small, ci ca 10%.
(a)
(b)
Figu e 24. Discha ge cha ac e is ics and capaci y o supe capaci o 10 °C and −10 °C: (a) discha ging
cu en 1 A; (b) discha ging cu en 2 A.
Figu e 24 shows he esul s o he beha io o he supe capaci o depending on he
empe a u e loading and he size o he load cu en . I is clea ha he empe a u e does
no ha e such an e ec on he beha io o supe capaci o s compa ed wi h elec ochemical
sou ces men ioned in he p e ious ex s a ing he esul s o he empe a u e analyses. An
example o he e ec o empe a u e in Li-ion is he measu emen esul s shown in Figu e
17. He e, he e ec o empe a u e change is no iceable, which is g ea e compa ed o su-
pe capaci o echnology. Ne e heless, acco ding o he esul , he empe a u e has e ec s
on he size o he in e nal esis ance o he supe capaci o , and his e ec inc eases wi h
he bias cu en , as is shown in Figu e 24. Figu e 24 shows he esul s only o +10 °C and
−10 °C because he esul s o +25 °C we e e y simila o hose o +10 °C. In conclusion,
i can be concluded ha supe capaci o s ha e a sligh in luence on empe a u e a nega i e
empe a u es. In addi ion, he li e a u e [50,51] conce ning he sel -discha ge, expe i-
men al, and compu a ional in es iga ion o supe capaci o s can be men ioned.
The e ec s o empe a u e on he beha io s o selec ed ene gy s o age echnologies
a e shown in Figu e 25. PEM Fuel Cells and supe capaci o s a e compa ed wi h he mos
used ba e y echnologies in he mili a y, which a e Ni-Cd ba e ies and Li-ion ba e ies.
Ob iously, he capaci y o supe capaci o s leas depends on empe a u e. Thei capaci o
in a wide empe a u e ange is almos cons an . On he con a y, he capaci y o ba e ies
signi ican ly dec eases when he empe a u e dec eases, especially when he empe a u e
d ops below 0 °C. In low-posi i e empe a u es, he capaci y o Ni-Cd ba e ies is also
e y poo , unde 50%, while Li-ion has a be e capaci y, abou 70%. PEM Fuel Cells ha e
inapplicable beha io s a nega i e empe a u es. The ou pu powe in hese empe a u es
is p ac ically ze o. Howe e , in posi i e empe a u es, he dependence o ou pu powe
on empe a u e is less conside able, only 10–20%.
Cha ac e is ics a
10°C and −10°C
a e e y simila
Capaci y a 2A
discha ing is
highe han 1A
Figu e 24. Discha ge cha ac e is ics and capaci y o supe capaci o 10
◦
C and
−
10
◦
C: (a) discha ging
cu en 1 A; (b) discha ging cu en 2 A.
Figu e 24 shows he esul s o he beha io o he supe capaci o depending on he
empe a u e loading and he size o he load cu en . I is clea ha he empe a u e does
no ha e such an e ec on he beha io o supe capaci o s compa ed wi h elec ochemical
sou ces men ioned in he p e ious ex s a ing he esul s o he empe a u e analyses.
An example o he e ec o empe a u e in Li-ion is he measu emen esul s shown in
Figu e 17. He e, he e ec o empe a u e change is no iceable, which is g ea e compa ed
o supe capaci o echnology. Ne e heless, acco ding o he esul , he empe a u e has
e ec s on he size o he in e nal esis ance o he supe capaci o , and his e ec inc eases
wi h he bias cu en , as is shown in Figu e 24. Figu e 24 shows he esul s only o
+10
◦
C and
−
10
◦
C because he esul s o +25
◦
C we e e y simila o hose o +10
◦
C. In
conclusion, i can be concluded ha supe capaci o s ha e a sligh in luence on empe a u e
a nega i e empe a u es. In addi ion, he li e a u e [
50
,
51
] conce ning he sel -discha ge,
expe imen al, and compu a ional in es iga ion o supe capaci o s can be men ioned.
The e ec s o empe a u e on he beha io s o selec ed ene gy s o age echnologies
a e shown in Figu e 25. PEM Fuel Cells and supe capaci o s a e compa ed wi h he mos
used ba e y echnologies in he mili a y, which a e Ni-Cd ba e ies and Li-ion ba e ies.
Ob iously, he capaci y o supe capaci o s leas depends on empe a u e. Thei capaci o
in a wide empe a u e ange is almos cons an . On he con a y, he capaci y o ba e ies
signi ican ly dec eases when he empe a u e dec eases, especially when he empe a u e
d ops below 0
◦
C. In low-posi i e empe a u es, he capaci y o Ni-Cd ba e ies is also
e y poo , unde 50%, while Li-ion has a be e capaci y, abou 70%. PEM Fuel Cells ha e
inapplicable beha io s a nega i e empe a u es. The ou pu powe in hese empe a u es
is p ac ically ze o. Howe e , in posi i e empe a u es, he dependence o ou pu powe on
empe a u e is less conside able, only 10–20%.
Ba e ies 2024,10, 43 25 o 29
Ba e ies 2024, 10, x FOR PEER REVIEW 26 o 30
Figu e 25. E ec o empe a u e on beha io o di e en echnologies.
4. Discussion, Conclusions, and Fu u e Wo k
4.1. Discussion
This a icle p esen s he s udy o ene gy s o age echnologies wi h a ocus on appli-
ca ion in mili a y EVs in mode n ba le ields. Wi h he inc easing in e es in using EVs in
many a mies, he main enance equi emen s need o be simpli ied and educed. One o
he mos p omising ways is o use elec ical d i es. These solu ions a e also in he same
di ec ion as he end o ba le ield elec i ica ion and digi aliza ion. All o hem equi e
sui able and ad an ageous solu ions o elec ical ene gy s o age. Among he exis ing en-
e gy s o age me hods, he choices a e ba e y echnologies, Fuel Cells, and supe capaci-
o s.
The cons uc ions o he mos common ba e y ypes and PEM FCs a e desc ibed in
his pape . The ma e ials and undamen al elec ochemical eac ions o each ba e y ype
a e also p esen ed. The cons uc ion o he PEM FC sys em is desc ibed wi h he disas-
sembly o he uni cell om he cu en PEM FC sys em, which p o ides a be e unde -
s anding o i s in e nal s uc u e. Ou pu cha ac e is ics o he PEM FC sys em a e expe -
imen ally e i ied. The esul s show ha a 0 °C (and minus empe a u es), PEM FC has
un a o able, inapplicable cha ac e is ics whe e he ou pu powe is ze o. This is an im-
po an ea u e ha equi es sui able design and cons uc ion o use FCs e icien ly in cold
en i onmen s. One p omising solu ion is o use a small seconda y hea sou ce o hea he
FC sys em on s a up. A e he FC sys em uns, he gene a ed hea can be used o sel -
wa m he en i e sys em, and a he same ime, he en ila o is eleased om he ope a ion,
so mo e ene gy is deli e ed o he ex e nal load. In addi ion, he managemen sys em,
simila o BMS, will be equi ed o manage he pa ame e s o he FC sys em and egula e
he seconda y hea sou ce, en ila o , and powe elec onic pa .
The popula and amilia cha ac e is ics o each ba e y ype we e expe imen ally
e i ied o p o ide be e knowledge abou hem. The au oma ic expe imen al wo kplace
was se up by using a DC load, mul ime e s, and he clima e chambe o e i y he beha -
io s o ba e ies in di e en ope a ing condi ions. The p og am unning in he VEEP o
en i onmen was used o con ol ins umen s and conduc da a acquisi ion. The expe i-
men al esul s a e hen g aphically p esen ed and b ie ly discussed.
No da a a 50°C
No da a a 50°C
Inapplicable powe a nega i e empe a u es
Signi ican capaci y dec ease
a nega i e empe a u es
Capaci y o
supe capaci y
less depends on
empe a u e
Figu e 25. E ec o empe a u e on beha io o di e en echnologies.
4. Discussion, Conclusions, and Fu u e Wo k
4.1. Discussion
This a icle p esen s he s udy o ene gy s o age echnologies wi h a ocus on appli-
ca ion in mili a y EVs in mode n ba le ields. Wi h he inc easing in e es in using EVs in
many a mies, he main enance equi emen s need o be simpli ied and educed. One o
he mos p omising ways is o use elec ical d i es. These solu ions a e also in he same
di ec ion as he end o ba le ield elec i ica ion and digi aliza ion. All o hem equi e sui -
able and ad an ageous solu ions o elec ical ene gy s o age. Among he exis ing ene gy
s o age me hods, he choices a e ba e y echnologies, Fuel Cells, and supe capaci o s.
The cons uc ions o he mos common ba e y ypes and PEM FCs a e desc ibed
in his pape . The ma e ials and undamen al elec ochemical eac ions o each ba e y
ype a e also p esen ed. The cons uc ion o he PEM FC sys em is desc ibed wi h he
disassembly o he uni cell om he cu en PEM FC sys em, which p o ides a be e
unde s anding o i s in e nal s uc u e. Ou pu cha ac e is ics o he PEM FC sys em a e
expe imen ally e i ied. The esul s show ha a 0
◦
C (and minus empe a u es), PEM
FC has un a o able, inapplicable cha ac e is ics whe e he ou pu powe is ze o. This is
an impo an ea u e ha equi es sui able design and cons uc ion o use FCs e icien ly
in cold en i onmen s. One p omising solu ion is o use a small seconda y hea sou ce o
hea he FC sys em on s a up. A e he FC sys em uns, he gene a ed hea can be used
o sel -wa m he en i e sys em, and a he same ime, he en ila o is eleased om he
ope a ion, so mo e ene gy is deli e ed o he ex e nal load. In addi ion, he managemen
sys em, simila o BMS, will be equi ed o manage he pa ame e s o he FC sys em and
egula e he seconda y hea sou ce, en ila o , and powe elec onic pa .
The popula and amilia cha ac e is ics o each ba e y ype we e expe imen ally e i-
ied o p o ide be e knowledge abou hem. The au oma ic expe imen al wo kplace was
se up by using a DC load, mul ime e s, and he clima e chambe o e i y he beha io s
o ba e ies in di e en ope a ing condi ions. The p og am unning in he VEEP o en i-
onmen was used o con ol ins umen s and conduc da a acquisi ion. The expe imen al
esul s a e hen g aphically p esen ed and b ie ly discussed.
In all measu emen s, he e ec o in e nal esis ance is clea ly shown. The in e nal
esis ance causes he dec ease o e minal ou pu ol age, as well as he Joule hea ing inside
he ba e y. Joule hea ing is some imes use ul, as i inc eases he in e nal empe a u e o he