Enhanced Elec ochemical Pe o mance o Binde -F ee
Fluo ine−Vanadium-Doped CoMoO4Nanoshee s ia In Si u MXene
In eg a ion o Ene gy S o age Applica ions
Monaam Benali,*Rasmi a Ba ik, Rui Gusmao, Jan Luxa, Pio W. Zabie owski, Amu ha Sub amani,
Bing Wu, and Zdenek So e *
Ci e This: ACS Appl. Ene gy Ma e . 2025, 8, 11513−11523
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sı Suppo ing In o ma ion
ABSTRACT: Designing an a o dable de ice ha seamlessly
combines e icien elec ochemical ene gy s o age wi h s aigh o -
wa d, obus p o ocols ep esen s a p omising pa hway o
ushe ing in he nex gene a ion o g een powe solu ions and
os e ing a sus ainable socie y. In his wo k, CoMoO4, anadium-
doped CoMoO4(V-CoMoO4), and luo ine− anadium-doped
CoMoO4(F-V-CoMoO4) we e syn hesized in si u on nickel oam
(NF) using a hyd o he mal me hod, ollowed by he mal
ea men , esul ing in a hie a chical s uc u e wi h in e connec ed
nanoshee s and open po ous channels. V2C MXene was used as
he anadium sou ce, which was ully oxidized du ing he syn hesis.
This unique a chi ec u e is pa icula ly ad an ageous o supe -
capaci o applica ions, as i acili a es e icien elec oly e low, p omo es he o ma ion o oxygen de ec s ha enhance ion anspo ,
and ul ima ely maximizes elec ochemical pe o mances. A a cu en densi y o 2.5 mA/cm2, he F-V-CoMoO4elec ode achie es
an a eal capaci ance o app oxima ely 2250 mF/cm2(900 F/g a 1 A/g), ou pe o ming p is ine CoMoO4(180 mF/cm2, 72 F/g)
and V-doped CoMoO4(810 mF/cm2, 324 F/g). An asymme ic supe capaci o is ab ica ed using an F-V-CoMoO4@NF//AC@NF
de ice and PVA/KOH gel elec oly e, showing excellen edox beha io and cycling s abili y, wi h 100% capaci y e en ion a e
2000 cycles a a cu en densi y o 1 Ag−1. Mo eo e , he de eloped de ice exhibi s a speci ic ene gy densi y o 11.5 Whkg−1and a
powe densi y o 225 Wkg−1a a cu en densi y o 0.3 A/g. These indings highligh he po en ial o F−V doping in enhancing he
elec ochemical p ope ies o CoMoO4-based elec odes.
KEYWORDS: ansi ion me al, doping, ene gy s o age, supe capaci o , hyd o he mal, MXene
1. INTRODUCTION
High ene gy densi y and long li espan supe capaci o s (SCs)
a e c ucial pe o mance me ics in mode n indus y, playing a
i al ole in ad ancing he g een economy,
1
pa icula ly in
esponse o he g owing demands o powe ing elec onics,
2
elec ic ehicles, and ene gy s o age solu ions.
3−5
Despi e
ad ances, cu en SC echnology, which elies on ca bon-based
ma e ials o conduc ing polyme s, is mainly limi ed by low
ene gy densi y, es ic ing hei widesp ead adop ion. Mo e-
o e , ecen ad ances in lase mic oannealing o Ni- ich
laye ed oxides on lexible polyme subs a es ha e opened
pa hways o in eg a ing high-pe o mance mic oca hodes in o
compac ene gy s o age sys ems and lexible elec onics.
6
In
his con ex , pseudocapaci i e ma e ials, such as hyb id o
modi ied ansi ion me al oxides, which exhibi apid and
highly e e sible oxida ion/ educ ion eac ion kine ics a o
nea he elec ode su ace, ha e he po en ial o simul aneously
achie e highe ene gy and powe densi ies.
6−8
Recen ly,
CoMoO4has d awn signi ican in e es as a SC elec ode
due o i s excep ional ca aly ic, elec ical, and s uc u al
p ope ies.
9−11
I s unique c ys alline s uc u e o e s ema k-
able hyb id capaci i e p ope ies, a ibu ed o i s high su ace
a ea, ich in e cala ion, and excellen ionic conduc i i y.
Howe e , CoMoO4’s inhe en ly low elec ical conduc i i y
and limi ed cycling s abili y may p esen challenges, making i
less sui able as a s andalone ma e ial o highly s able and long-
las ing elec odes.
12
A p omising s a egy o add ess he
a o emen ioned challenges in ol es doping CoMoO4o
ab ica ing CoMoO4-based composi es.
13
These app oaches
enable he exploi a ion o he in insic p ope ies o he hos
ma e ial and uning o bo h i s mo phology and s uc u e. Such
Recei ed: June 1, 2025
Re ised: July 6, 2025
Accep ed: July 7, 2025
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modi ica ions can in oduce addi ional elec ochemically ac i e
si es and enhance ion di usion kine ics by sho ening he ionic
anspo pa hway, ac o s ha a e bene icial o such an
elec ochemical ene gy s o age sys em. No ably, he Ni-doped
CoMoO4elec ode showed a highe speci ic capaci ance alue,
supe io a e capabili y, and lowe p is ine CoMoO4due o
syne gis ic mul ime al edox ansi ions and enhanced
conduc i i y. Simila ly, he inco po a ion o lan hanum (La)
elemen s in o he CoMoO4la ice wi h a nanocube s uc u e
demons a ed a syne gis ic e ec be ween he me al oxide and
La dopan , leading o imp o ed elec ochemical pe o mance.
I achie ed a speci ic capaci ance o 1552.7 F/g a a scan a e
o 5 mV/s, app oxima ely ou imes highe han he p is ine
elec ode, and main ained abou 98% e en ion wi h 99%
Coulombic e iciency.
14
Mo eo e , he e os uc u es, such as
CoMoO4@CoP g own in si u on bo on-doped g aphene
ae ogel,
15
CoMoO4@NiS2co e−shell,
16
NiCo@NiOOH@
CoMoO4co e−shell,
7
and so on, ha e demons a ed
signi ican enhancemen in elec ochemical ene gy s o age
pe o mance. These s udies emphasize he c ucial ole o he
enginee ed mo phology and s uc u e in op imizing he
elec ochemical cha ac e is ics o CoMoO4elec odes. Pa ic-
ula ly, ea u es including high disloca ion densi ies, la ice
dis o ion, abundan oxygen acancies, and a ich edox
beha io con ibu e o enhanced pe o mance.
14,15
In addi ion,
he educ ion in cha ge ans e esis ance (Rc ) leads o an
inc eased numbe o elec ochemically accessible ac i e si es
and a la ge su ace a ea,
17
he eby imp o ing ion anspo
and elec ical conduc i i y. These imp o emen s ul ima ely
esul in supe io capaci ance and high s abili y o he modi ied
CoMoO4elec ode.
18−20
In ecen s udies, MXene-CoMoO4composi es ha e
exhibi ed syne gis ic enhancemen s in cha ge s o age, sugges -
ing he bene i s o combining laye ed 2D ma e ials wi h
ansi ion me al oxides.
20
In his ega d, we conduc ed a comp ehensi e in es iga ion
o he p ope ies o F-V-CoMoO4composi es, which we e
g own in si u on Ni oam using a wo-s ep hyd o he mal
me hod, ollowed by an annealing p ocess. These composi es
a e subsequen ly employed as high-pe o mance supe capaci-
o elec odes. The F-doping and unique composi e a e
designed o enhance elec ochemical pe o mance, esul ing
in p omising p ope ies o ad anced ene gy s o age
applica ions. A no el syn hesis app oach was adop ed o
de elop high-pe o mance CoMoO4-based elec odes by
combining V2C MXene, cobal molybda e p ecu so s, and
NH4F. Rema kably, du ing syn hesis, he V2C MXene is
comple ely oxidized, wi hou aces o he o iginal MXene o
any VOxphase de ec ed. Ins ead, he p ocess induced he
o ma ion o unique F-V-CoMoO4nanoshee s, po en ially
ea u ing inely dispe sed VOxspecies and/o inco po a ed V
a oms, which signi ican ly enhanced he elec ochemical
p ope ies o CoMoO4. Vanadium(V) has a small ionic adius
and can adop mul iple oxida ion s a es, each associa ed wi h a
di e en ionic adius, which p omo es he elec onic
ansi ions ha a e c ucial o he elec ochemical cha ge
s o age eac ion. Mo eo e , i s syne gis ic in e ac ion wi h
o he ansi ion me als can une he o e all elec onic
s uc u e, a o ing elec on ans e and inducing abundan
elec oac i e si es.
21,22
Addi ionally, he aim o inco po a ing
luo ine (F) in o he CoMoO4ma ix is o ailo i s su ace
s uc u e and induce he o ma ion o oxygen de ec s, he
modi ica ion ha has been p o en e ec i e in enhancing
elec ochemical pe o mance.
23,24
Supe capaci o s equi e high-pe o mance elec ode ma e i-
als wi h excellen elec ical conduc i i y and ion anspo
p ope ies. In his wo k, we in es iga e he impac o
anadium(V) and luo ine (F) doping on he elec onic
s uc u e and ion anspo p ope ies o CoMoO4by using
DFT simula ions wi h Quan um ATK. Ou esul s indica e
ha doping wi h V and F signi ican ly enhances he densi y o
s a es (DOS) nea he Fe mi le el and lowe s he e ec i e
po en ial ba ie . The calcula ed wo k unc ion dec eases om
6.3 eV o p is ine CoMoO4 o 5.6 eV o doped CoMoO4,
indica ing imp o ed elec on emission p ope ies. These
imp o emen s make V- and F-doped CoMoO4a p omising
candida e o nex -gene a ion ene gy s o age de ices.
2. EXPERIMENTAL DETAILS
2.1. Ma e ials. All chemicals used in his wo k we e o analy ical
eagen g ade and we e used wi hou u he pu i ica ion. Cobal
chlo ide hexahyd a e (100%) and po assium hyd oxide (KOH) we e
p o ided by Lach-Ne , while sodium molybda e dihyd a e (99.5%)
and ammonium luo ide we e pu chased om Sigma-Ald ich. U ea
(99%) was ob ained om he PENTA Company. The nickel oam
subs a e (99.9%) had a hickness o 0.3 mm.
2.2. Syn hesis o P is ine CoMoO4, V-Doped CoMoO4, and
F-V-Doped CoMoO4.2.2.1. P is ine CoMoO4.1 g o cobal chlo ide
hexahyd a e (CoCl2·6H2O), 0.96 g o sodium molybda e dihyd a e
(Na2MoO4·2H2O), and 0.152 g o u ea we e each dissol ed sepa a ely
in 20 mL o deionized wa e . The solu ions we e hen combined and
magne ically s i ed o 30 min, o ming a uni o m pu ple solu ion.
The abo e solu ion was ans e ed in o a 120 mL Te lon-lined
s ainless-s eel au ocla e, wi h a slice o p e ea ed nickel oam (NF)
placed inside. The hyd o he mal ea men was ca ied ou a 180 °C
o 12 h. The p ecu so on NF was ho oughly insed wi h deionized
wa e and absolu e e hanol o supp ess weakly adhe ed CoMoO4and
o he impu i ies on he su ace, ollowed by d ying a 60 °C o e nigh .
Finally, he p ecu so was subjec ed o calcina ion in an ai
a mosphe e a 350 °C o 2 h o o m c ys allized CoMoO4.
2.2.2. V-CoMoO4.We adop ed a simila p o ocol o he
p epa a ion o he V-doped CoMoO4composi e. Fi s , 1 g o
CoCl2·6H2O, 0.152 g o u ea, and 0.96 g o Na2MoO4·2H2O we e
sepa a ely dissol ed in 20 mL o deionized wa e . Simul aneously, 100
mg o V2C MXene was sonica ed in 40 mL o deionized wa e o 30
min. V2C MXene was syn hesized, as epo ed in he p e ious wo k.
25
The solu ions we e hen combined and magne ically s i ed o 1 h.
The esul ing mix u e was ans e ed o a 120 mL au ocla e wi h a
slice o p e ea ed NF placed inside. The hyd o he mal ea men was
conduc ed a 180 °C o 12 h. The ea e , he NF subs a e was
ho oughly washed wi h deionized wa e and e hanol, d ied a 60 °C
o e nigh , and inally calcined in an ai a mosphe e a 350 °C o 2 h.
2.2.3. Fluo ine−Vanadium-Doped CoMoO4(F-V-CoMoO4). The
F-doped sample was p epa ed by ollowing he same p ocedu e as
desc ibed abo e. Speci ically, 1 g o NH4F was dissol ed sepa a ely in
20 mL o deionized wa e and hen mixed wi h he p e iously
p epa ed solu ions. The mix u e was subjec ed o he same
hyd o he mal ea men as ou lined in he abo e p o ocol.
2.3. Cha ac e iza ion. Powde X- ay di ac ion (XRD) pa e ns
o he syn hesized ma e ials we e collec ed by using a B uke D8
Ad ance di ac ome e equipped wi h a Cu Kα adia ion sou ce (λ=
1.5406 Å). The ins umen was ope a ed a 40 kV and 40 mA, wi h
measu emen s eco ded o e a 2θ ange o 4−90°and a scanning
speed o 2°pe minu e. The mo phology o he ma e ials was
examined by scanning elec on mic oscopy (SEM) wi h an FEG
elec on sou ce (Tescan Maia dual-beam mic oscope) a a 5 kV
accele a ion ol age. The elemen al composi ion o syn hesized
ma e ials was in es iga ed by ene gy-dispe si e X- ay spec oscopy
(EDX) using an X-MaxNde ec o om Ox o d Ins umen s, wi h a 20
kV accele a ion ol age. Samples we e di ec ly placed on a C o Cu
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ape. Raman spec oscopy was pe o med using a Renishaw InVia
spec ome e o iden i y he cha ac e is ic ib a ional modes o he
samples. Measu emen s we e ca ied ou a oom empe a u e o e a
spec al ange o 100−2000 cm−1, u ilizing a He−Cd lase wi h an
exci a ion wa eleng h o 532 nm. A 20×objec i e lens was employed
o ensu e p ecise ocus on he sample, wi h he lase powe se o 5
mW. The speci ic su ace a ea o he p oposed elec odes was
de e mined by using he B unaue −Emme −Telle (BET) me hod.
N2adso p ion−deso p ion measu emen s we e ca ied ou wi h a
Quan ach ome NOVA Touch 4LX ins umen . High- esolu ion X- ay
pho oelec on spec oscopy (XPS) was conduc ed by using a
monoch oma ic aluminum sou ce (1486.7 eV). Comp ehensi e
su ey scans we e i s pe o med o de ec all elemen s, ollowed
by de ailed high- esolu ion scans o he C 1s, Co 2p, Mo 3d, O 1s, V
3d, F 1s. The in si u g own samples on NF we e posi ioned on a
conduc i e subs a e o measu emen s.
2.4. Elec ochemical Measu emen s and Elec ode P epa a-
ion. An Au olab PGSTAT 204 (No a, U ech , The Ne he lands)
was used o all elec ochemical measu emen s, including cyclic
ol amme y (CV), gal anos a ic cha ge−discha ge (GCD), ch o-
noampe ome y, and elec ochemical impedance spec oscopy (EIS).
EIS analysis was pe o med in he equency ange o 10 mHz o 100
kHz a ze o ol age bias. In he h ee-elec ode sys em, he ins a e
cobal molybda e on NF was used as a ee binde wo king elec ode,
pla inum (P ) was used as he coun e elec ode, and Hg/HgO was
used as he e e ence elec ode. All o he elec ochemical cha ac e -
is ics we e ob ained in 6 M KOH aqueous solu ions.
A eal capaci ance (Ca eal), speci ic capaci ance, ene gy densi y, and
powe densi y a e de e mined om he gal anos a ic cha ge−
discha ge plo s using he ollowing equa ions:
Ci
A V
(F cm )
a eal
2=
×
×
(1)
Ci
m V
sp =
×
×
(2)
EC
Ene gy densi y (Whkg ), 1
2
V
3.6
12
=
×
(3)
PE
Powe densi y (Wkg ), 3600
1=
×
(4)
whe e ideno es he cu en , is he discha ge ime, Ais he a ea o
elec odes, and ΔVis he po en ial window.
2.5. Densi y Func ional Theo y Calcula ions. 2.5.1. Compu a-
ional Me hodology. Densi y unc ional heo y (DFT) calcula ions
we e pe o med using he Quan umATK so wa e package wi h he
gene alized g adien app oxima ion (GGA) and he Pe dew−Bu ke−
E nze ho (PBE) exchange-co ela ion unc ional.
26
To accoun o
long- ange an de Waals in e ac ions, G imme’s DFT-D3 dispe sion
co ec ions we e inco po a ed. A plane-wa e cu o ene gy o 500 eV
was used, ensu ing su icien accu acy and con e gence o he o al
ene gy. The B illouin zone was sampled using a 3 ×3×1 k-poin
mesh wi hin he Monkho s −Pack scheme. Con e gence es s we e
conduc ed o con i m he adequacy o hese compu a ional
pa ame e s. Doping was in oduced by subs i u ing selec Co and O
a oms wi h V and F a oms, espec i ely. S uc u al elaxa ion was
pe o med un il he o al ene gy con e ged wi hin 10−5eV. The
elec onic s uc u e, including he p ojec ed densi y o s a es, was
analyzed o assess he impac o doping on he ma e ial’s elec onic
p ope ies. Wo k unc ion calcula ions we e ca ied ou using slab
models o e alua e changes in su ace elec onic cha ac e is ics. These
compu a ional se ings and analysis me hods ensu e a eliable
in es iga ion o he doped sys em’s s uc u al and elec onic
p ope ies.
3. RESULTS AND DISCUSSION
3.1. Analysis and Elec ochemical Pe o mance o he
Posi i e Elec ode Ma e ials. Scheme 1 illus a es he
schema ic ep esen a ion o F-V-CoMoO4wi h dual de ec s
syn hesized on nickel oam. The doping elemen s and de ec
o ma ion we e achie ed h ough a hyd o he mal me hod.
Du ing he sequen ial nuclea ion and c ys al g ow h s ages,
ex olia ed V2C MXene shee s unde go hyd olysis, leading o
hei in si u deposi ion along wi h F-CoMoO4p ecu so s on
he g ow h subs a e. In his p ocess, oxygen a oms a e pa ially
eplaced by luo ine, gene a ing oxygen de ec s si es.
Subsequen ly, he calcined samples p omo e he c ys alliza ion
o he CoMoO4 backbone, inco po a ing MXene-de i ed
anadium a oms and luo ine modi ica ion, he eby enhancing
he s uc u al in eg i y and elec ochemical p ope ies o
CoMoO4. The mo phologies o he di e en syn hesized
composi e ma e ials a e cha ac e ized using scanning elec on
mic oscopy (SEM), as illus a ed in Figu e 1. Following he
hyd o he mal g ow h p ocess, he su ace o he Ni oam is
uni o mly coa ed wi h well-aligned CoMoO4nanoshee s, as
depic ed in Figu e 1a,b. This uni o m co e age indica es a
con olled and e ec i e deposi ion, esul ing in a cohe en
nanoshee ac oss he oam subs a e. In Figu e 1b, he
CoMoO4nanoshee s exhibi a highly in e connec ed a ange-
men , o ming a hie a chical s uc u e wi h open and po ous
spaces. This a chi ec u e is pa icula ly ad an ageous o
supe capaci o applica ions, as he open s uc u e acili a es
e icien elec oly e low up, while he la ge su ace a ea could
a o ion anspo and maximize elec ochemical ac i i y.
Simila ly, he V-CoMoO4sample showed an in e connec ed
shee s uc u e, making i di icul o dis inguish any
mo phological di e ences om he p is ine sample. Based on
Figu e 1e, , he nanoshee s exhibi in e connec i i y, o ming a
well-o ganized s uc u e wi h a po ous ex u e. This a ange-
men esul s in a highly o de ed a ay, con ibu ing o he F-V-
CoMoO4composi e s uc u al in eg i y.
The X- ay di ac ion (XRD) pa e ns p esen ed in Figu e 2a
indica e ha he cha ac e is ic peaks o p is ine CoMoO4
obse ed a 2θ alues o 28.1, 32.8, 33.6, 38.89, 43.12, and
58.8°can be assigned o he (−311), (−222), (400), (040),
(113), (−424), and (260) planes o monoclinic phase (JCPDS
No. 21-0868), espec i ely. The phase s a es o V-CoMoO4
and F−V-@CoMoO4samples a e also in es iga ed. Fo V-
Scheme 1. Schema ic Illus a ion o he Syn hesis P ocess o
F-V-CoMoO4on Nickel Foam
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CoMoO4, he majo di ac ion peaks co espond o CoMoO4,
wi h a b oad peak a ound a 2θ alue o 15°, which was
a ibu ed o he p esence o ca bon. No dis inc peaks a e
obse ed o con i m he phases o anadium oxide o V2C
MXene. This indica es ha he V2C MXene is comple ely
oxidized, wi h no emaining aces o he o iginal MXene
s uc u e o any in e media e VOxphase de ec ed. Addi ion-
ally, we no e ha he oxida ion o MXene can p oceed h ough
in e media e educed anadium species du ing he hyd o-
he mal s ep, which is subsequen ly oxidized du ing ai
calcina ion o o m VOx. Howe e , due o hei likely
amo phous o low-c ys allini y na u e, VOxphases may no
be clea ly de ec able by XRD. Simila ly, luo ine doping did
no in oduce any new phases o impu i ies ela ed o he
inco po a ion o F ions.
The Raman spec a o CoMoO4and F-V-CoMoO4samples
p esen ed in Figu e 2b exhibi he cha ac e is ic peaks a 934,
813, and 334 cm−1co esponding o he symme ic/
asymme ic s e ching mode o he MoO4 e ahed al, O−
Mo−O, and Mo−O−Co bonds, espec i ely.
9,27
The peak
obse ed a app oxima ely 1090 cm−1is likely a ibu able o
he cobal phase, a ib a ional mode ha has no been
p e iously epo ed in CoMoO4.
9
The absence o any Raman
peak shi o in ensi y inc ease upon doping wi h F and V
a oms sugges s ha he band s uc u e o CoMoO4 emains
unchanged. This indica es ha he MoO4 e ahed al uni s and
he Co−O−Mo amewo k a e no signi ican ly dis o ed a e
modi ica ion. Addi ionally, he lack o new peaks o b oadening
implies ha no seconda y phases ha e o med, sugges ing ha
he dopan s ei he weakly in e ac wi h he backbone s uc u e
o a e inco po a ed in a way ha does no al e he ib a ional
symme y. This is indica i e ha F and V a e subs i u ing in
la ice si es o occupying in e s i ial posi ions. Figu e S1a,b
depic he ene gy-dispe si e X- ay spec oscopy (EDX)
spec um and he EDX elemen al mapping, espec i ely, o
he CoMoO4shee s, con i ming he p esence o Co and Mo
Figu e 1. SEM images o (a,b) CoMoO4, (c,d) V-CoMoO4, and (e, ) F-V-CoMoO4.
Figu e 2. X- ay di ac og ams o (a) p is ine CoMoO4(black), V-CoMoO4(o ange), and F-V-CoMoO4(blue). (b) Raman spec a o CoMoO4,
F-V-CoMoO4, and (c,d) EDX spec um and elemen al mapping images o F -V-CoMoO4, espec i ely.
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me als along wi h O, consis en wi h he oxide composi ion.
The quan i iable a omic amoun s o Co and Mo a e nea ly
equal, u he alida ing he success ul o ma ion o he
CoMoO4phase. Simila ly, as illus a ed in Figu e 2c,d, he
EDX analysis o he F-V-CoMoO4sample e eals a uni o m
dis ibu ion o Co, Mo, V, and C elemen s. F a oms we e also
de ec ed in ce ain a eas, likely as a esul o localized doping
o su ace adso p ion.
XPS analysis was pe o med on he CoMoO4, V-CoMoO4,
and F-V-CoMoO4samples o iden i y hei elemen al
composi ions and he oxida ion s a es o each cons i uen
elemen . The su ey spec um, shown in Figu e 3a, e eals he
p ima y elemen s Co, Mo, and O, co esponding o he
CoMoO4phase. Addi ionally, he p esence o doping elemen s
V and F was also obse ed.
The high- esolu ion Co 2p spec um o p is ine CoMoO4
displays wo dis inc spin−o bi double peaks loca ed a 781.4
and 797.2 eV, along wi h wo sa elli e peaks a 786.9 and 803.4
eV (Figu e 3b). Fo he V-CoMoO4sample, he spin−o bi
double peaks appea a 780.7 and 797.0 eV, wi h sa elli es
obse ed a 785.8 and 802.5 eV. Simila ly, in he F-V-CoMoO4
sample, he spin−o bi double peaks a e loca ed a 781.3 and
797.2 eV, co esponding o Co 2p3/2 and Co 2p1/2,
espec i ely, and a e accompanied by sa elli e peaks a 786.5
and 803.1 eV, ypically a ibu ed o cobal oxide species.
23,24,28
O e all, he peak shapes and posi ions a e in good ag eemen
wi h p e ious epo s on CoMoO4.
29
Fu he mo e, he spin−o bi spli ing (ΔE) o ∼16 eV
con i ms he p esence o he Co2+ species in he sample. Based
on p io esea ch conduc ed by Oku and Hi okawa,
30
i has
been es ablished ha ΔE alues a e in luenced by he oxida ion
s a e, wi h ΔEabou 15 eV o diamagne ic cobal ous
compounds (Co3+) and ΔEo 16 eV o pa amagne ic
cobal ous compounds (Co2+). The obse ed ΔEo ∼16 eV in
his s udy is consis en wi h he pa amagne ic Co2+
con igu a ion. Addi ionally, he de ec ion o sa elli e peaks,
which a e gene ally absen in sys ems domina ed by Co3+,
exhibi s addi ional e idence suppo ing he p edominance o
Co2+. These indings align he elec onic s a e o cobal in F-V-
CoMoO4and i s co ela ion wi h he obse ed spec al
ea u es.
Figu e 3c p esen s he high- esolu ion spec a o Mo 3d. Fo
he CoMoO4sample, he spec um can be decon olu ed in o
ou componen s loca ed a 230.3 and 233.5 eV, co esponding
o he Mo 3d5/2 and Mo 3d3/2 spin−o bi componen s o Mo4+,
espec i ely. Addi ionally, a second pai o peaks loca ed a
233.6 and 236.8 eV o igina es om Mo6+. The ΔEo
app oxima ely 3.2 eV aligns wi h he cha ac e is ic ea u es o
Mo 3d, as epo ed in he li e a u e.
31,32
Compa ed o he
p is ine sample, he F- and V-doped samples only possess he
Mo6+ componen , indica ing addi ional oxida ion o Mo du ing
he hyd o he mal syn hesis. Acco ding o Table S1, he Co
con en inc eases wi h V doping (V-CoMoO4: 9.9%)
compa ed o p is ine CoMoO4(6.88%), sugges ing ha
anadium migh enhance he s abiliza ion o Co wi hin he
s uc u e. Howe e , he educ ion in Co con en in F-V-
CoMoO4(8.89%), along wi h a simila dec ease in Mo
con en , indica es a po en ial compe i ion o edis ibu ion o
elemen s caused by he in oduc ion o luo ine. This
edis ibu ion could signi ican ly al e he elec onic p ope ies
o he ma e ial. In he O 1sspec a (Figu e 3d), wo peaks a
530.22 and 531.50 eV in unmodi ied CoMoO4a e assigned o
la ice oxygen and ad en i ious oxygen, espec i ely. Upon
inco po a ion o F and V a oms in CoMoO4la ices, hese
peaks exhibi a sligh shi o lowe binding ene gies, appea ing
a 529.84 and 531.84 eV in he F-V-doped sample. This shi
coupled wi h he s eady inc ease in oxygen con en obse ed in
Table S1, eaching i s highes alue in F-V-CoMoO4(54.01%),
sugges s enhanced oxida ion o he o ma ion o mo e
oxygen−me al bonds. In addi ion, he inc ease in oxygen
amoun p o ides mo e e idence ha luo ine doping no only
al e s he su ace chemis y bu also a o s anadium oxida ion,
po en ially imp o ing he ma e ial’s oxida i e capaci y.
23,33
As
shown in Figu e S2b, he i ed V 2p3/2 spec um o he F-V-
CoMoO4sample exhibi s peaks a 514.6, 515.7, and 516.76 eV,
while he V 2p1/2 spec um exhibi s peaks a 522.20, 523.30,
and 524.36 eV. These peaks co espond o V3+, V4+, and V5+
oxida ion s a es, espec i ely.
34,35
The educed V con en in F-
V-CoMoO4(0.57%) sugges s ha luo ine pa ially o se s he
inco po a ion o anadium, likely due o he in e play be ween
hese doping elemen s. On he su ace o CoMoO4, di e en
o ms o VOxspecies can exis �isola ed, polyme ic, and
c ys alline. Thei abili y o be educed ( educibili y) dec eases
as hey become mo e polyme ized: isola ed VOxis he easies
o educe, ollowed by polyme ic species, and c ys alline
species exhibi ing he lowes educibili y.
36
This hie a chy
a ises because s onge in e ac ions be ween anadium and he
CoMoO4suppo de elop wi h highe deg ees o polyme -
iza ion, which p og essi ely hinde he educ ion p ocess.
Addi ionally, he p esence o he F1speak nea 685.1 eV
(Figu e S2c) is indica i e o he o ma ion o F-me al bonds,
con i ming he success ul inse ion o F a oms in o he
CoMoO4s uc u e.
23,24
Figu e S3 displays he ni ogen
adso p ion−deso p ion iso he ms o he syn hesized samples.
The BET analysis de e mined he speci ic su ace a eas o be
201.7, 206.8, and 140.3 m2/g o CoMoO4, V-CoMoO4, and F-
V-CoMoO4, espec i ely. I is wo h no ing ha a highe
su ace a ea ypically enhances cha ge s o age capaci y by
p o iding excessi e elec oac i e si es. Howe e , elec o-
chemical pe o mance is also in luenced by o he ac o s
such as conduc i i y, po e s uc u e, and induced de ec s.
Figu e 3. XPS spec a o CoMoO4, V-CoMoO4, and F-V-CoMoO4:
(a) su ey spec um, (b−d) high- esolu ion spec a o (b) Co 2p, (c)
Mo 3d, and (d) O 1sand V 2p.
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These can play a c ucial ole in imp o ing conduc i i y and
acili a ing ion di usion.
3.2. Elec ochemical Pe o mances. To e alua e he
p ac ical use o CoMoO4, V-CoMoO4, and F-V-CoMoO4
g own in si u on Ni oam elec odes in elec ochemical ene gy
s o age, hei elec ochemical pe o mance is assessed using a
h ee-elec ode sys em. The syn hesized ma e ials we e used as
he wo king elec ode, while pla inum oil and Hg/HgO se ed
as he coun e and e e ence elec odes, espec i ely. Figu e 4a
p esen s a compa a i e CV cu e o di e en elec odes,
ca ied ou in a 6 M KOH aqueous elec oly e a a scan a e o
1 mV/s. The CV cu es display a dis inc pai o edox peaks,
indica ing ha he capaci ance p ima ily a ises om he
Fa adaic edox mechanism associa ed wi h M-O bonds, whe e
M deno es Co, Mo, V, o F. No ably, he F-V-CoMoO4@NF
elec ode exhibi s he la ges enclosed CV cu e a ea,
signi ying a highe speci ic capaci ance compa ed wi h o he
samples. This imp o emen can be a ibu ed o he doping
e ec since F−V doping inc eases he a ea o he CV cu es
due o mo e ac i e si es accessible o ion anspo .
Figu es 4b and S4a show he CV cu es o he CoMoO4
elec ode eco ded a scan a es anging om 1 o 30 mV/s. In
all cu es, a dis inc pai o edox peaks a e obse ed,
co esponding o he Co2+/Co3+ and Co3+/Co4+ edox, along
wi h he oxida ion o Mo ions. No ably, while Mo ions
ypically do no pa icipa e in he educ ion p ocess unde
no mal condi ions, he in oduc ion o s uc u al de ec s can
c ea e ac i e si es ha enable he educ ion o Mo6+ o
Mo5+7, 37. Fu he mo e, as he scan a e inc eases, he cu en
alues o bo h oxida ion and educ ion peaks a e enhanced and
shi ed, indica ing he occu ence o quasi- e e sible edox
eac ions a he elec ode−elec oly e in e ace. The shi in he
peak posi ion is a ibu ed o cha ge di usion pola iza ion
wi hin he elec ode. Simila ly, he CV cu es o V-CoMoO4
(Figu e S4b) and F-V-CoMoO4(Figu e 4c) elec odes a
di e en scan a es show a linea inc ease in cu en densi y,
along wi h a no iceable shi in he edox peak posi ions. This
beha io indica es imp o ed cha ge ans e kine ics and
enhanced elec ochemical ac i i y due o he inco po a ion o
V and F dopan s, which likely in oduce addi ional ac i e si es
and acili a e ion di usion.
The o al capaci ance o he elec ode consis s o wo
dis inc con ibu ions: su ace-con olled capaci i e beha io
and di usion-con olled cha ge s o age. The p opo ion o
di usion-con olled capaci ance can be quan i a i ely e alua ed
using Dunn’s equa ion:
i k k
1 2
1/2
= +
(5)
whe e ibelongs o he cu en (A), νdeno es he scan a e o
he CV es (mV/s), k1 ep esen s he su ace-con olled
capaci i e con ibu ion, and k2co esponds o he di usion-
con olled con ibu ion. To ob ain hese pa ame e s, a linea
plo
i/1/2
e sus
1/2
is adop ed (Figu e S4c,d), whe e he
slope and in e cep p o ide he k1and k2, espec i ely.
38
As
illus a ed in Figu e 4d, he F-V-CoMoO4elec ode demon-
s a es he highes su ace-con olled capaci i e con ibu ion,
wi h alues o 80, 84, 86, and 88% a scan a es o 1, 2, 3, and 4
mV/s, espec i ely. This inding sugges s ha he capaci i e
beha io domina es, while he di usion con ibu ion g adually
diminished in e sely wi h inc easing scan a e due o he
limi ed ime a ailable o he ion di usion eac ion. The
capaci i e con ibu ion can also be quan i a i ely analyzed
Figu e 4. (a) CV cu es o CoMoO4, V-CoMoO4, and F-V-CoMoO4elec odes eco ded a a scan a e o 1 mV/s. (b,c) CV cu es o CoMoO4
and F-V-CoMoO4elec odes a di e en scan a es anging om 1 o 4 mV/s. (d) P opo ion o capaci i e- and di usion-con olled Fa adaic
con ibu ion o cha ge s o age in F-V-CoMoO4elec odes a a ious scan a es. (e) Compa a i e GCD p o iles o p is ine CoMoO4, V-CoMoO4,
and F-V-CoMoO4elec odes. ( ) GCD p o iles o he F-V-CoMoO4elec ode a di e en cu en densi ies. (g) Co esponding a eal capaci ances
a a ious cu en densi ies. (h) Compa ison o Nyquis diag ams o CoMoO4, V-CoMoO4, and F-V-CoMoO4.
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using he equa ion i=aνb, whe e i ep esen s he cu en
esponse, and νdeno es he scan a e. He e, aand ba e
adjus able cons an s, wi h bob ained om he slope o log i
e sus log ν.
39
In he case o he F-V-CoMoO4elec ode
(Figu e S4 ,g), he calcula ed b alues a e 0.92 o he
oxida ion peak and 0.87 o he educ ion peak, con i ming a
su ace-con olled eac ion mechanism.
Figu e 4e p esen s compa a i e GCD plo s ob ained a a
cu en densi y o 2.5 mA/cm2(1 A/g) o e alua e he
capaci ance cha ac e is ics o he elec odes wi hin he
po en ial ange o 0−0.5 V. No ably, he p esence o a ol age
pla eau in he GCD cu e indica es he occu ence o
oxida ion− educ ion eac ions du ing he elec ochemical
p ocess, consis en wi h he CV cha ac e iza ion esul s.
Mo eo e , he F-V-CoMoO4elec ode exhibi s a signi ican ly
longe discha ge ime compa ed o bo h p is ine and V-doped
CoMoO4elec odes.
To e alua e he capaci i e p ope ies o F-V-CoMoO4, GCD
measu emen s a e conduc ed wi h he ab ica ed elec odes
and measu ed a di e en cu en densi ies anging om 2.5 o
12.5 mA/cm2(Figu e 4 ). The symme ical shape o he GCD
cu es indica es he e e sibili y o he a adic edox eac ion,
wi h a high Coulombic e iciency o 93%. We u he analyzed
he Coulombic e iciency o e a ange o cu en densi ies,
which shows a dec ease o p is ine CoMoO4, as p esen ed in
Figu e S4h. Howe e , he Coulombic e iciency emains s able
a a ound 93% o he F-V-CoMoO4elec ode. The a eal
capaci ance esul s a e illus a ed in Figu e 4g, whe e he
CoMoO4and V-doped samples exhibi ed capaci ance alues o
180 and 810 mF/cm2, espec i ely, a a cu en densi y o 2.5
mA/cm2. In con as , he F-V-CoMoO4elec ode demon-
s a ed signi ican ly highe capaci ance, anging om 2125
mF/cm2a 12.5 mA/cm2(Csp = 850 F/g a 5 A/g) o 2250
mF/cm2a 2.5 mA/cm2(Csp = 900 F/g a 1 A/g), which
achie ed he highes capaci ance among he e alua ed ma e ial.
The capaci i e p ope ies o F-V-CoMoO4a e be e han
hose epo ed o some con en ional modi ied CoMoO4-
based elec odes, including CoMoO4@ educed g aphene
composi es, as shown in Table S2. This subs an ial capaci ance
pe o mance unde sco es he supe io elec ochemical p ope -
ies o he F-V-CoMoO4elec ode and can be a ibu ed o he
in ica ely de eloped mo phology, he abundance o exposed
edox-ac i e si es, he syne gis ic e ec o a coexis ence o
me allic ion edox pai , and he po en ial o F−V in modula ing
he edox eac ion.
Elec ochemical impedance spec oscopy (EIS) is essen ial
o e alua ing he in insic esis ance a he elec ode−
elec oly e in e ace. By applying a sinusoidal pe u ba ion a
ze o bias, he impedance is measu ed as a unc ion o
equency in he ange o 10 mHz o 100 kHz. Figu e 4h
p esen s he Nyquis plo s, whe e he F-V-CoMoO4elec ode
shows a no iceably educed semici cle adius in he high-
equency egion. This educ ion indica es e ec i e cha ge
ans e a he semiconduc o /Ni oam in e ace. Addi ionally,
he eme gence o his semici cle unde sco es he c i ical impac
o in e ace e ec s on he elec ical p ope ies o he in ol ed
elec odes.
3.3. E alua ion o F-V-CoMoO4//AC Asymme ic
Supe capaci o s in PVA/KOH Gel Elec oly es. An
asymme ic supe capaci o (ASC) de ice is ab ica ed using a
binde - ee F-V-CoMoO4elec ode di ec ly g own on Ni oam
o u he e alua e i s elec ochemical p ope ies and sui abili y
o p ac ical applica ion. The de ice is assembled wi h
ac i a ed ca bon as he nega i e elec ode, while he mic o-
ibe s se e as sepa a o s. Addi ionally, an all-solid-s a e
asymme ic de ice (F-V-CoMoO4@NF//AC@NF) is con-
s uc ed using a PVA-KOH gel elec oly e o assess i s
pe o mance a oom empe a u e, as illus a ed in Figu e 5a.
P io o he analysis, he elec ochemical p ope ies o he
ac i a ed ca bon we e e alua ed using he 6 M KOH
elec oly e, as shown in Figu e 5b. The po en ial window o
he F-V-CoMoO4elec ode anges om −0.1 o 0.5 V, while
ha o he AC/CC elec ode ex ends om −0.8 o 0.2 V. This
b oad po en ial ange indica es ha he ol age o he F-V-
CoMoO4/CC//AC/CC asymme ic de ice can be ex ended
o a highe po en ial, he e o e amelio a ing i s ene gy s o age
capaci y.
Fu he mo e, he mass loading o he posi i e elec ode (F-
V-CoMoO4) is balanced h ough he ollowing cha ge balance
equa ion:
m
m
c V
c V
=
+
+ +
(6)
whe e, m+and m−co espond o he mass loading on posi i e
and nega i e elec odes, while he c+and c−a e he speci ic
capaci ances o F-V-CoMoO4and ac i a ed ca bon in F g−1,
espec i ely. V+p esen s he applied posi i e po en ial o F-V-
CoMoO4, and V−is he supplied po en ial o ac i a ed
ca bon.
37
Figu e 6a p esen s he CV cu es eco ded a di e en
applied ol ages anging om 0 o 1.4 V−2 V, all measu ed a a
cons an sweep a e o 20 mV s−1. The ob ained CV cu es
emain consis en ac oss a ious po en ial windows, which
e lec a s able elec ochemical beha io . The ASC de ice
exhibi s nea ly symme ic cu es up o 1.5 V, sugges ing good
capaci i e pe o mance. Howe e , oxygen e olu ion eac ions
(OERs) occu beyond his ol age h eshold, de ining 0−1.5 V
as he op imal wo king po en ial o he ASC de ice. In
addi ion, CV measu emen s conduc ed a a scan a e anging
om 1 o 50 mVs−1(Figu e 6b), demons a ing ha he cu es
e ain hei shape, con i ming he s abili y o he de ice and i s
abili y o main ain pe o mance wi hou de e io a ing a e
capabili y. A a lowe scan a e o 1−3 mVs−1, dis inc edox
peaks a e obse ed in he CV cu es, indica i e o he a adaic
p ocess associa ed wi h a slowe kine ic eac ion. Howe e , as
he scan a e inc eases om 10 o 50 mVs−1, he edox peaks
g adually diminish and become in isible due o he as e
kine ic eac ion. A hese high scan a es, he CV cu es exhibi
quasi- e e sible beha io . The symme ic GCD cu es a e
ob ained up o a po en ial o 1.5 V, showing good Coulombic
Figu e 5. (a) Schema ic p esen a ion o ASC de ice ab ica ion. (b)
Cyclic ol amme y cu es o ac i a ed ca bon and he F-V-CoMoO4
ma e ial a a scan a e o 5 mVs−1.
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e iciency. Beyond his po en ial, e iciency dec eases wi h
inc easing ol age, likely due o side eac ions o elec oly e
decomposi ion. Addi ionally, di e en GCD cu es a e
ob ained a a ious cu en densi ies, also demons a ing
good Coulombic e iciency, as gi en in he inse o Figu e
6c. The de ice demons a es excellen e e sible cycling
s abili y, main aining 100% capaci ance e en ion up o 2000
cycles a a cu en densi y o 1 A g−1. Beyond his, o up o
3000 cycles, app oxima ely 94% o he ini ial capaci ance is
e ained, as shown in Figu e 6d. The de ice achie es a
maximum speci ic capaci ance o 36.2 F g−1a a cu en
densi y o 0.3 A g−1, showing excellen Coulombic e iciency.
This high symme y in he cha ge−discha ge cu es u he
con i ms he supe io elec ochemical pe o mance and
s abili y o he F-V-CoMoO4@NF//AC@NF de ice. The
speci ic capaci ances o he F-V-CoMoO4@NF//AC@NF
de ice a di e en cu en densi ies a e calcula ed using eq 2
and p esen ed in Figu e 6d (inse ), along wi h he Coulombic
e iciency a di e en cu en densi ies. A a cu en densi y
below 0.3 A g−1, he cha ge−discha ge cu e loses i s
symme y, and he Coulombic e iciency dec eases. No ably,
all GCD cu es om 2 o 0.3 A g−1exhibi ba e y- ype
beha io . A maximum powe densi y o 1500 W kg−1is
obse ed, while he ASC de ice deli e s a high speci ic ene gy
densi y o 11.5 W kg−1and a speci ic powe densi y o 225
Whkg−1a a cu en densi y o 0.3 A g−1. These alues a e
illus a ed and compa ed o o he modi ied CoMoO4-based
ma e ials in he Ragone plo p esen ed in Figu e 6e.
14,44−46
The elec ochemical (EIS) beha io s o he ASC de ice ha e
been s udied and a e shown in Figu e 6 . The ob ained Nyquis
plo s a e i ed, and he co esponding equi alen ci cui
diag am is gi en in he inse o Figu e 6 . The high- equency
egion p o ides a small in e nal esis ance o 0.58 Ωand an
equi alen se ies esis ance o 1.66 Ω, indica ing low in e nal
esis ance and e icien cha ge anspo . Mo eo e , he
Nyquis plo is nea ly pa allel o he Y-axis, sugges ing a
di usion-limi ed elec on ans e p ocess. A small Wa bu g
esis ance is also obse ed, along wi h he capaci ance
beha io . Fu he mo e, he EIS analysis con i ms he enhanced
elec ochemical s abili y o he F-V-CoMoO4@NF//AC@NF
de ice.
37,40
The excellen elec ochemical pe o mance o he
ASC de ice can be asc ibed o se e al ac o s: (i) he wide
applied po en ial window o 1.7 V signi ican ly inc eases he
ene gy densi y o supe capaci o s; (ii) CoMoO4a ibu es o
he pseudo capaci ance beha io , while he F and V may
suppo he EDLC capaci ance wi h high conduc i i y; (iii) he
s ong in e ac ion be ween F−V wi h CoMoO4ensu es he
ema kable cycling and a e pe o mance o he F-V-
CoMoO4@NF//AC@NF de ice; and (i ) doping o F and
V meaning ully imp o es he elec ochemical pe o mance
owing o he po ous s uc u e ha acili a es ion anspo and
suppo s a apid edox eac ion.
41,42
Ne e heless, he p esence
o F and V con ibu es o he high supe capaci o pe o mance
o he CoMoO4ma e ial. Mo phological e alua ion o he
elec odes a e ex ensi e cycling can yield aluable s uc u al
and elec ochemical insigh s. Following long- e m cycling
(3000 cycles), he F-V-CoMoO4nanoshee s e ained hei
s uc u al a chi ec u es wi h minimal de o ma ion, as con-
i med by SEM imaging in Figu e S5.
The op imized s uc u es o p is ine and V- and F-doped
CoMoO4a e shown in Figu e 7a,b. Doping leads o sligh
la ice dis o ions, indica ing s uc u al s abili y upon sub-
s i u ion. Bo h s uc u es showed a ze o band gap, indica ing
ha hei me al cha ac e is ics we e sui able o as elec on
anspo in ca alysis.
43
The p ojec ed densi y o s a es
(PDOS) analysis e eals ha V and F doping signi ican ly
al e s he elec onic s uc u e by in oducing impu i y s a es
nea he Fe mi le el, enhancing cha ge ans e . The V
inco po a ion om V2C leads o hyb idiza ion wi h Mo
o bi als, con ibu ing o enhanced elec onic conduc i i y
Figu e 6. Asymme ic sys em (F-V-CoMoO4@NF//AC@NF): (a) CV cu es a di e en po en ial windows and a a scan a e o 40 mV s−1, (b)
CV cu es a di e en scan a es om 1 o 50 mV s−1, (c) GCD cu es a a cu en densi y o 0.8 A g−1, (d) cycle s abili y up o 3000 cycles and
GCD cu es a cu en densi ies anging om 2 o 0.8 A g−1(inse ), (e) Ragone plo , speci ic capaci ance alues in F g−1and Coulombic
e iciencies in % a di e en cu en densi ies (inse ), and ( ) Nyquis plo wi h he ci cui diag am (inse ).
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h ps://doi.o g/10.1021/acsaem.5c01660
ACS Appl. Ene gy Ma e . 2025, 8, 11513−11523
11520
(Figu e 7c,d). The wo k unc ion, a c ucial pa ame e o
elec on emission and su ace eac i i y, was compu ed o
bo h p is ine and doped CoMoO4. The p is ine CoMoO4
exhibi s a wo k unc ion o 6.3 eV, whe eas he V, F-doped
CoMoO4shows a educed wo k unc ion o 5.6 eV. This
dec ease indica es an enhanced elec on ans e capabili y,
which can acili a e be e elec ochemical pe o mance and is
consis en wi h he ob ained enhancemen o he expe imen al
measu emen s.
The inc eased DOS nea he Fe mi le el and lowe ed wo k
unc ion sugges imp o ed conduc i i y and ion anspo ,
making doped CoMoO4an excellen candida e o supe -
capaci o elec odes. These insigh s p o ide a heo e ical
ounda ion o expe imen al alida ion.
4. CONCLUSIONS
In summa y, CoMoO4, V-CoMoO4, and F-V-CoMoO4
samples a e success ully syn hesized ia a hyd o he mal
me hod, ollowed by he mal calcina ion a 350 °C. O e all,
he combined e ec o F and V doping al e s he s uc u al
p ope ies o CoMoO4and induces de ec s such as oxygen
acancies and in e s i ials ha signi ican ly enhance i s
elec ochemical pe o mance. Especially, he F-V-CoMoO4
elec ode achie es an a eal capaci ance o app oxima ely
2250 mF/cm2a a cu en densi y o 2.5 mA/cm2(Csp =
900 F/g a 5 A/g), ou pe o ming he p is ine CoMoO4(180
mF/cm2, 72 F/g) and V-doped CoMoO4(810 mF/cm2, 324
F/g). Addi ionally, an asymme ic supe capaci o is assembled
using an F-V-CoMoO4@NF//AC@NF de ice, demons a ing
he edox beha io o he ma e ial wi h excellen cycling
s abili y, and 100% capaci y e en ion a e 2000 cycles is
achie ed a a cu en densi y o 1A g−1. Fu he mo e, he
de ice exhibi s a high speci ic ene gy densi y o 11.5 Whkg−1
and a speci ic powe densi y o 225 Wkg−1a a cu en densi y
o 0.3 A g−1. V and F doping in CoMoO4, as e ealed by DFT
calcula ions, signi ican ly enhances i s elec onic p ope ies by
in oducing impu i y s a es nea he Fe mi le el and educing
he wo k unc ion, leading o imp o ed conduc i i y and
cha ge ans e . This esul pa es he way o u he
explo a ion and de elopmen o modi ied CoMoO4-based
elec odes o e icien elec ochemical ene gy s o age sys ems.
■ASSOCIATED CONTENT
Da a A ailabili y S a emen
The da a se s gene a ed and/o analyzed du ing he cu en
s udy a e a ailable in he Zenodo eposi o y: h ps://zenodo.
o g/ eco ds/15303730.
*
sı Suppo ing In o ma ion
The Suppo ing In o ma ion is a ailable ee o cha ge a
h ps://pubs.acs.o g/doi/10.1021/acsaem.5c01660.
Expe imen al de ails, cha ac e iza ion me hods including
SEM images; EDX spec um; elemen al mapping
images; high- esolu ion spec a o C 1s, V 2p, and F
1s; ni ogen adso p ion−deso p ion iso he m spec a o
CoMoO4, V-CoMoO4, and F-V-CoMoO4; CV cu es o
CoMoO4and V-CoMoO4; plo s o
i/1/2
e sus
1/2
adop ed o calcula e k1 and k2 a a ious po en ials o
he F-V-CoMoO4elec ode; p opo ion o capaci i e
and di usion-con olled Fa adaic con ibu ion o cha ge
s o age in he CoMoO4elec ode a a ious scan a es;
log(i) e sus log(ν) plo s o he F-V-CoMoO4elec ode
using oxida ion and educ ion peaks, Coulombic
e iciency a e o p is ine and F−V-doped CoMoO4a
di e en applied cu en densi ies; SEM image o he F-
V-CoMoO4elec ode a e 3000 cycles o GCD;a omic
pe cen ages (a .%) o su ace elemen s in pu e CoMoO4,
V- CoMoO4, and F−V- CoMoO4samples as ob ained
om he XPS analysis and compa ison o elec o-
chemical pe o mance enhancemen o he syn hesized
F-V-CoMoO4-based elec ode wi h p e iously epo ed
modi ied CoMoO4in a h ee elec odes sys em (Table
S2) (PDF)
■AUTHOR INFORMATION
Co esponding Au ho s
Monaam Benali −Depa men o Ino ganic Chemis y,
Uni e si y o Chemis y and Technology P ague, 166 28
P ague 6, Czech Republic; o cid.o g/0000-0003-4398-
5498; Email: [email p o ec ed]
Zdene
k So e −Depa men o Ino ganic Chemis y,
Uni e si y o Chemis y and Technology P ague, 166 28
P ague 6, Czech Republic; o cid.o g/0000-0002-1391-
4448; Email: [email p o ec ed]
Au ho s
Rasmi a Ba ik −Depa men o Ino ganic Chemis y,
Uni e si y o Chemis y and Technology P ague, 166 28
P ague 6, Czech Republic
Rui Gusmao−Depa men o Ino ganic Chemis y, Uni e si y
o Chemis y and Technology P ague, 166 28 P ague 6,
Czech Republic
Jan Luxa −Depa men o Ino ganic Chemis y, Uni e si y o
Chemis y and Technology P ague, 166 28 P ague 6, Czech
Republic; o cid.o g/0000-0001-9076-5389
Pio W. Zabie owski −Depa men o Ino ganic Chemis y,
Uni e si y o Chemis y and Technology P ague, 166 28
P ague 6, Czech Republic
Amu ha Sub amani −Depa men o Ino ganic Chemis y,
Uni e si y o Chemis y and Technology P ague, 166 28
P ague 6, Czech Republic; o cid.o g/0000-0002-9937-
3020
Bing Wu −Depa men o Ino ganic Chemis y, Uni e si y o
Chemis y and Technology P ague, 166 28 P ague 6, Czech
Republic; o cid.o g/0000-0002-9637-6787
Figu e 7. Op imized s uc u es o (a) CoMoO4and (b) V, F-doped
CoMoO4. P ojec ed densi y o s a es o (c) CoMoO4and (d) V, F-
doped CoMoO4.
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h ps://doi.o g/10.1021/acsaem.5c01660
ACS Appl. Ene gy Ma e . 2025, 8, 11513−11523
11521
