Regula A icle
Tailo ing poly( inylidene luo ide- i luo oe hylene-chlo o luo oe hylene)
memb ane mic os uc u e o li hium-ion ba e y sepa a o applica ions
Ra ael S. Pin o
a,b
, Jo˜
ao P. Se a
a
, Jo˜
ao C. Ba bosa
b
, Ma ia M. Sil a
b
, Manuel Salado
c
,
A kai z Fidalgo Ma ijuan
c,d
, Ede Amayuelas
e
, Ya osla G osu
e,
, Rena o Gonçal es
b
,
Senen xu Lance os-Mendez
a,c,g
, Ca los M. Cos a
a,h,*
a
Physics Cen e o Minho and Po o Uni e si ies (CF-UM-UP) and Labo a o y o Physics o Ma e ials and Eme gen Technologies, LapMET, Uni e si y o Minho,4710-
057 B aga, Po ugal
b
Cen e o Chemis y, Uni e si y o Minho, 4710-057 B aga, Po ugal
c
BCMa e ials, Basque Cen e o Ma e ials, Applica ions and Nanos uc u es, UPV/EHU Science Pa k, 48940 Leioa, Spain
d
Depa men o O ganic and Ino ganic Chemis y, Uni e si y o he Basque Coun y UPV/EHU, 48940 Leioa, Spain
e
Cen e o Coope a i e Resea ch on Al e na i e Ene gies (CIC ene giGUNE), Basque Resea ch and Technology Alliance (BRTA), Ala a Technology Pa k, Albe Eins ein
48, 01510 Vi o ia-Gas eiz, Spain
Ins i u e o Chemis y, Uni e si y o Silesia in Ka owice, Szkolna 9, 40-006 Ka owice, Poland
g
Ike basque, Basque Founda ion o Science, 48009 Bilbao, Spain
h
Ins i u e o Science and Inno a ion o Bio-Sus ainabili y (IB-S), Uni e si y o Minho, 4710-057 B aga, Po ugal
HIGHLIGHTS GRAPHICAL ABSTRACT
•P(VDF-T FE-CFE) memb anes ha e been
de eloped o ba e y sepa a o
applica ions.
•The memb anes we e p epa ed by
di e en p ocessing echniques.
•The p ocessing condi ions allow uning
mo phology and po osi y.
•The bes li hium ans e ence numbe is
0.55, ob ained o memb ane p epa ed
by sal leaching.
•A discha ge capaci y alue o 74 mAh.
g
−1
a 1C- a e has been ob ained o he
memb anes p epa ed by sal leaching.
ARTICLE INFO
Keywo ds:
PVDF e polyme
P(VDF-T FE-CFE)
Memb anes
P ocessing echniques
Sepa a o
Li hium-ion ba e ies
ABSTRACT
No el ba e y sepa a o s based on poly( inylidene luo ide-co- i luo oe hylene-chlo o luo oe hylene)–P(VDF-
T FE-CFE)- we e p oduced by di e en p ocessing echniques (non-sol en and he mally induced phase sepa-
a ion, sal leaching and elec ospinning), in o de o e alua e hei e ec on sepa a o mo phology, deg ee o
po osi y and po e size, elec ochemical pa ame e s and ba e y cycling beha io . I has been demons a ed ha
he di e en p ocessing echniques ha e a signi ican in luence on he mo phology and mechanical p ope ies o
memb anes. The deg ee o po osi y a ies be ween 23 % and 66 %, o memb anes ob ained by sal leaching and
he mally induced phase sepa a ion, espec i ely.
* Co esponding au ho a : Physics Cen e o Minho and Po o Uni e si ies (CF-UM-UP) and Labo a o y o Physics o Ma e ials and Eme gen Technologies,
LapMET, Uni e si y o Minho, 4710-057 B aga, Po ugal.
E-mail add ess: [email p o ec ed] (C.M. Cos a).
Con en s lis s a ailable a ScienceDi ec
Jou nal o Colloid And In e ace Science
jou nal homepage: www.else ie .com/loca e/jcis
h ps://doi.o g/10.1016/j.jcis.2024.11.013
Recei ed 10 June 2024; Recei ed in e ised o m 21 Oc obe 2024; Accep ed 3 No embe 2024
Jou nal o Colloid and In e ace Science 680 (2025) 714–724
A ailable online 8 No embe 2024
0021-9797/© 2024 The Au ho (s). Published by Else ie Inc. This is an open access a icle unde he CC BY license (
h p://c ea i ecommons.o g/licenses/by/4.0/ ).
The memb anes p esen a high ionic conduc i i y alue anging be ween 1.8 mS.cm
−1
o he elec ospun
memb ane and 0.20 mS.cm
−1
o he memb ane p ocessed by he mally induced phase sepa a o . The li hium
ans e ence numbe alue o all memb anes is abo e 0.20, he highes alue o 0.55 being ob ained o samples
p epa ed by sal leaching and he mally induced phase sepa a ion.
Fo all memb anes, ba e y capaci y alues ha e been ob ained a di e en C- a es wi h excellen e e sibili y.
P(VDF-T FE-CFE) samples p esen an excellen ba e y pe o mance a 1C- a e a e 100 cycles wi h 74 mAh.g
−1
and excellen coulombic e iciency, o memb ane p ocessed by he sal leaching echnique. This wo k demon-
s a es ha P(VDF-T FE-CFE) e polyme can be used as a po ous memb ane in li hium-ion ba e y sepa a o
applica ion, he memb ane p ocessing echnique allowing o ailo i s mo phology and, consequen ly, ba e y
pe o mance.
1. In oduc ion
In oday’s highly echnological socie y ha la gely depends on
mobili y and ene gy, he de elopmen o mo e en i onmen ally iendly
and e icien ene gy s o age sys ems o po able elec onic de ices and
elec ic ehicles becomes inc easingly necessa y [1,2]. Addi ionally,
e ec i e ene gy s o age sys ems a e key o educing ossil uels con-
sump ion as hey can e ec i ely s o e he powe gene a ed by enewable
ene gy gene a ion sou ces, which in u n helps mi iga e clima e change
and global wa ming [3,4]. The e a e se e al ene gy s o age sys ems ha
can be di ided in o elec ochemical, mechanical, hyd o, he mal, mag-
ne ic, o pneuma ic, among o he s, whe e li hium-ion ba e ies (LIBs)
belong o elec ochemical de ices [4]. Rega ding LIBs, hey a e one o
he mos popula ene gy s o age de ices wi h a ma ke g ow h a e o
8.5 % wo ldwide [5,6]. Despi e his achie emen and i s applicabili y,
u he esea ch is needed o imp o e he cha ac e is ic p ope ies o i s
a ious componen s, i.e., he elec odes, he sepa a o /elec oly e o
con en ional ba e ies and he solid elec oly e o solid-s a e ba e ies
[7,8]. The global ma ke o con en ional LIBs was $46.2 billion in
2022, and om 2023 o 2032, i is expec ed o inc ease by 15.2 % and
ha his inc ease is accompanied by pe o mance and sa e y imp o e-
men s [9]. The sepa a o is a c i ical componen o good ope a ion o
such de ices, as i elimina es sho ci cui s du ing cha ge–discha ge
p ocesses, con ols cell kine ics, and inhibi s dynamics dend i e g ow h.
Sepa a o s can be di ided in o di e en ypes, such as, single polyme ,
composi es, polyme blends, elec ospun, nonwo en and su ace modi-
ied sepa a o s [10]. Independen ly o he sepa a o ype, i is composed
o a po ous memb ane and an elec oly e solu ion whe e his solu ion is
ypically composed by li hium sal s dissol ed in an o ganic sol en and/
o ionic liquids [11,12].
The mo phology (po osi y/po e size) o he sepa a o , which in-
luences i s he mal, mechanical, and ionic conduc i i y, as well as i s
we abili y and in e ac ion wi h he elec oly e solu ion, a e wha
de e mine he sepa a o ’s p ima y cha ac e is ics and unc ional
esponse [10].
In o de o ailo he mo phology o he sepa a o , he memb anes
can be p oduced by di e en echniques, such as, elec ospinning (ES),
sal -leaching (SL), sol en cas ing wi h he mally (TIPS) and non-sol en
induced phase sepa a ion (NIPS), among o he s. Di e en polyme s
ha e been implemen ed as sepa a o memb anes, including poly-
p opylene (PP) [13], poly(ac yloni ile) (PAN) [14], poly(me hyl
me hac yla e) (PMMA) [15], poly (e he -e he -ke one) (PEEK) [16],
poly(e hylene oxide) (PEO) [17], polye he imide (PEI) [18], poly(s y-
ene-b-bu adiene-b-s y ene) (SBS) block copolyme [19], poly( inyli-
dene luo ide) (PVDF) and i s copolyme s [20,21], cellulose [22], silk
ib oin [23], ca ageenan [24], among o he s. In compa ison o o he
polyme ypes, PVDF and i s copolyme s a e hea ily esea ched in he
ield o sepa a o memb anes due o hei ailo able memb ane o ming
p ope ies, chemical ine ness, compa ibili y wi h elec oly e solu ion,
and s abili y a unc ional empe a u es and high ol ages. Addi ionally,
hey exhibi ou s anding mechanical p ope ies, a manageable deg ee o
c ys allini y, and high dielec ic alue ha can enhance he ioniza ion o
li hium sal s [25].
In o de o ob ain sepa a o s wi h high ionic conduc i i y alue and
imp o ed he mal and mechanical p ope ies, PVDF polyme s’mos
ecen sepa a o esea ch has ocused on he s udy o composi es and
blends [21]. Fo PVDF base sepa a o s o his ype, i is impo an o
inc ease we abili y, u he adjus mo phology o p ope ly une po e
size, imp o e he supp ession o dend i es, and imp o e li hium ions
mobili y in o de o allow he widesp ead use and comme cial success o
his sepa a o ype.
Conside ing he dielec ic cons an alue o PVDF, which is one o
he mos impo an p ope ies o a sepa a o memb ane, he PVDF
e polyme poly( inylidene luo ide- i luo oe hylene-chlo o luo o
e hylene), P(VDF-T FE-CFE), shows a high dielec ic cons an , anging
om 25 o 50 which is impo an o he ioniza ion o li hium sal s.
Fu he mo e, his e polyme p esen s chemical and adia ion esis-
ance, sui able he mal and mechanical p ope ies, good elec oly e
we abili y and excellen p ocessabili y, bu i has ne e been used in
ene gy s o age applica ions [26].
In his scope, i is essen ial o p ope ly une memb ane po osi y and
po e size, which a e c i ical pa ame e s in memb ane p ope ies o
ba e y sepa a o s. This can be achie ed by p ope selec ion o he
p ocessing echnique and hei associa ed p ocessing pa ame e s. Gi en
his, he de elopmen o po ous memb anes based on P(VDF-T FE-CFE)
p ocessed by a ious me hods, including TIPS, NIPS, elec ospinning,
and sal leaching, is he main objec i e o his wo k, aiming o demon-
s a e o he i s ime ha his polyme may be sui able o ba e y
sepa a o memb ane applica ions. The mic os uc u al, he mal, me-
chanical and elec ochemical p ope ies o he de eloped memb anes
a e p esen ed and discussed, as well as hei unc ional esponse once
implemen ed as ba e y sepa a o s.
2. Expe imen al
2.1. Ma e ials
Poly ( inylidene luo ide- i luo oe hylene-chlo o luo oe hylene) (P
(VDF-T FE-CFE)) (Piezo ech®RT-FS; Mw =500 kg.mol
−1
; 62.5/29/8.5
mol.% o VDF, T FE and CFE, espec i ely), he sol en N,N
-dime-
hyl o mamide (DMF, 99 %) and Sodium chlo ide (NaCl) we e supplied
by Piezo ech, Me ck and Sigma-Ald ich, espec i ely. The sol en N-
me hylpy olidinone (NMP), he con en ional elec oly e 1 mol.dm
−3
LiPF
6
in e hylene ca bona e-dime hyl ca bona e (EC-DMC, 1:1 ol) and
li hium-me allic we e pu chased om Sigma-Ald ich.
Fo ca hode elec ode de elopmen , poly( inylidene luo ide) PVDF,
Kyna PVDF HSV900, ca bon black (Supe P-C45) and C-LiFePO
4
(LFP)
we e acqui ed by A kema, Timcal G aphi e &Ca bon and Phos ech
Li hium, espec i ely.
2.2. Memb ane p epa a ion
The memb ane samples we e p epa ed using ou di e en p epa-
a ion echniques: he mally induced phase sepa a ion (TIPS), non-
sol en induced phase sepa a ion (NIPS), sal leaching (SL) and elec-
ospinning (ES). Fi s , ou solu ions we e p epa ed by mixing P(VDF-
R.S. Pin o e al. Jou nal o Colloid And In e ace Science 680 (2025) 714–724
715
T FE-CFE) in a DMF solu ion (20/80 w %), unde magne ic s i ing.
A e he polyme was comple ely dissol ed, wo o hem we e submi -
ed o a doc o blade echnique in a glass subs a e. A e ha , one was
e apo a ed in an o en (JP selec a) a 25 ◦C (TIPS) and he o he one was
subme ged in a non-sol en −dis illed wa e (NIPS). The hi d solu ion
was submi ed o an elec ospinning echnique, s a ing by in oducing
he ob ained solu ion in o he elec ospinning se up, using a plas ic sy-
inge connec ed o a low egula o om Sy ingepump, USA. A e ha ,
a high ol age (model PS/FC30P04) was applied be ween he sy inge
and an aluminum oil subs a e (whe e he elec ospun ibe s a e
collec ed, o ming a ma ), in o de o c ea e a je . Deposi ion condi ions
we e 20 kV bias, 0.4 ml.h
−1
low a e, 0.5 mm needle diame e and 12
cm needle-collec o dis ance.
Wi h espec o he ou h solu ion, a e he polyme was comple ely
dissol ed, NaCl was added o he solu ion, in a 1:1 polyme :NaCl weigh
a io. La e , when he sal pa icles we e p ope ly dispe sed, he solu ion
was p ocessed wi h he doc o blade echnique in a glass subs a e and
placed in an o en, a 25 ◦C. A e ob aining he d ied ilm, i was washed
in dis illed wa e , unde magne ic s i ing o 72 h. The p oduced
memb anes a e iden i ied in he ollowing acco ding o hei p ocessing
echnique name, i.e., NIPS, TIPS, ES and SL. The hickness o he
memb anes is 75, 120, 169 and 193
μ
m o he memb anes ob ained by
NIPS, SL, TIPS and ES echniques, espec i ely.
2.3. Cha ac e iza ion echniques
The mo phology (su ace and c oss-sec ion images) o P(VDF-T FE-
CFE) memb anes was examined by scanning elec on mic oscope
(SEM, Ca l Zeiss EVO 40 EDX Ox o d Ins umen s) wi h a 20 kV accel-
e a ing ol age. The memb anes we e p e iously coa ed wi h a gold
laye (Pola on, ype SC502).
The po osime y o he samples was de e mined by me cu y po os-
ime y in an Au o Po e IV 9500 po osime e (Mic ome i ics Ins umen
Co po a ion, No c oss, USA), whe e he pene ome e was e acua ed o
a p essu e less han 7 Pa, ollowed by illing wi h me cu y o 365 MPa.
Samples we e ou gassed a 110 ◦C o e nigh p io o measu emen . A
con ac angle o 140◦, a su ace ension o 480 dyn⋅cm
−1
o me cu y
and a p essu e equilib a ion ime o 10 s we e used.
Con ac angle measu emen s we e pe o med using 3 µL d ople s o
ul apu e wa e and elec oly e solu ion (1 M LiPF
6
in EC:DMC) wi h a
Da a Physics OCA20 de ice a oom empe a u e. Fo each memb ane,
h ee measu emen s we e aken a di e en loca ions on he memb ane
o calcula e he a e age con ac angle.
A Jasco FT/IR-6100 was used o pe o m Fou ie T ans o m In a ed
Spec oscopy in A enua ed To al Re lec ion mode (FTIR/ATR) om
4000 o 600 cm
−1
wi h 64 scans a a esolu ion o 4 cm
−1
.
A Me le -Toledo DSC 822e was used o ob ain di e en ial scanning
calo ime y (DSC) cu es om 30 o 200 ◦C a a hea ing a e o 10 ◦C.
min
−1
unde a ni ogen low o 20 mL.min
−1
in aluminum c ucibles.
Using a NETZSCH STA 449F3 he mobalance, he mog a ime ic
(TGA) he mog ams we e ob ained. Memb anes we e placed in alumina
c ucibles wi h app oxima ely 10 mg o sample and hea ed be ween 30
and 800 ◦C a a a e o 5 ◦C.min
−1
.
S ess–s ain measu emen s we e ca ied ou in a TST350 Linkam
ins umen a a s ain a e o 15
μ
m.s
−1
in o de o assess he mechanical
p ope ies o he ma e ial a oom empe a u e.
2.4. Elec oly e up ake and elec ochemical cha ac e iza ion
The elec oly e up ake (
ε
) was es ima ed using Eq. (1) as a unc ion o
ime while he memb anes we e subme ged in a 1 mol.dm
−3
LiPF
6
in EC:
DMC solu ion:
ε
=(M−M0
M0)×100% (1)
whe e M
0
is he memb ane weigh and Mis he memb ane weigh a e
imme sion in he elec oly e solu ion.
Using an Au olab PGSTAT-12 (Eco Chemie) and a cons an olume
suppo (gold elec odes | sepa a o memb ane | gold elec odes), he
ionic conduc i i y (
σ
i
) alue o he po ous memb anes was calcula ed.
The suppo was hen placed wi hin a Büchi TO 50 o en. Wi h a 50 mV
s imula ion ampli ude and a equency ange om 65 kHz o 500 mHz,
impedance measu emen s we e ca ied ou a oom empe a u e. The
ionic conduc i i y alue was calcula ed using Eq. (2):
σ
i=
A*Rb
(2)
whe e is he hickness o he memb ane, Ais he a ea o he memb ane
and R
b
is he bulk esis ance ob ained by in e cep o he imagina y
impedance (minimum alue o Z
″
) wi h he slan ed line in he eal
impedance (Z
′
).
Eqs. (3) and (4), we e used o ob ain he To uosi y (
τ
) and Mac-
Mullin numbe (N
M
), espec i ely:
τ
=
σ
0
ε
σ
i
√(3)
NM=
σ
0
σ
i
(4)
whe e,
σ
0
is he ionic conduc i i y o he 1 mol.dm
−3
LiPF
6
in EC:DMC
solu ion (11.6 mS.cm
−1
a 25 ◦C),
ε
is he po osi y o he memb ane and
σ
i
is he ionic conduc i i y o he memb ane a e he up ake p ocess.
The elec ochemical s abili y o he sepa a o memb anes was
assessed h ough cyclic ol amme y in a glo e box using a wo elec-
odes con igu a ion wi h a li hium disk as he coun e elec ode and a
gold mic oelec ode as he wo king elec ode. The measu emen s we e
pe o med wi h an Au olab PGSTAT-12 (Eco Chemie) a a scan a e o
0.01 V.s
−1
.
A po en ios a /gal anos a (Au olab PGSTAT-12) was used o mea-
su e he Li-ion ans e ence numbe (
Li
+
) using symme ic memb ane
cells (10 mm) sandwiched be ween wo Li me al elec odes (8 mm) a
oom empe a u e [27].
The Li-ion ans e ence numbe (
Li
+
) was calcula ed by Eq. (5) using
he me hod p oposed in [28,29]:
Li+=Is[ΔV−I0R0]
I0[ΔV−IsRs](5)
whe e, I
0
and I
s
a e he ini ial and s eady cu en s, espec i ely. R
0
and
R
s
a e he ini ial and inal esis ances o he in e acial laye s o he Li
elec ode/elec oly e.
2.5. Ca hode and li hium cell p epa a ion and cycling pe o mance
The ba e y ca hode was ab ica ed wi h he ollowing componen
pe cen ages: 80 w % C-LiFePO
4
, 10 w % ca bon black, and 10 w %
PVDF, combined in 2.25 mL o NMP as polyme sol en . The s udy in
[30] p o ides mo e de ailed in o ma ion on he elec ode p epa a ion.
The esul an slu y was hen cas ed by doc o -blade on o and aluminum
oil and allowed o d y a 80 ◦C o wo hou s. The ac i e mass loading o
he ca hodes was app oxima ely 3.8–4.2 mg.cm
−2
.
In a homemade, a gon- illed glo e box, Swagelok ype Li/C-LiFePO
4
hal -cells we e p epa ed wi h he ollowing componen s: a po ous
memb ane sepa a o (10 mm in diame e ) o he di e en ypes de el-
oped in he wo k imme sed in elec oly e solu ion; a me allic li hium (8
mm in diame e ) oil anode elec ode; and o he p e iously de eloped
C-LiFePO
4
based ca hode elec ode. Expe imen s wi h Wha man®
comme cial glass ib e sepa a o we e also pe o med o compa ison.
Cha ge-discha ge es s we e pe o med a oom empe a u e using a
Land CT2001A ins umen , in he ol age ange o 2.5 V o 4.2 V, a
R.S. Pin o e al. Jou nal o Colloid And In e ace Science 680 (2025) 714–724
716
cu en a es o C/8 o 2C (C =170 mA.g
−1
).
Elec ochemical impedance spec oscopy (EIS) (Au olab PGSTAT12)
was used o examine he elec ical cha ac e is ics o he Li/C-LiFePO
4
hal -cells wi h he p epa ed sepa a o memb anes in he equency ange
om 10 mHz o 1 MHz, wi h an ampli ude o 10 mV AC ol age signal.
3. Resul s and discussion
3.1. Mo phology and deg ee o po osi y
The mo phology o memb anes is shown in he in su ace and c oss-
sec ional SEM images p esen ed in Fig. 1 o all p ocessing echniques,
all memb anes showing a po ous mo phology.
Fo he sample p epa ed by NIPS (Fig. 1a-–b–) he po osi y is e enly
dis ibu ed h oughou he samples. This mo phology is due o he liq-
uid–liquid de-mixing ha caused he phase sepa a ion be ween he DMF
sol en and dis illed wa e (non-sol en ) wi hin he coagula ion ba h
[31].
Rega ding he samples ob ained by TIPS, po ous memb anes wi h
i egula po es wi h dimensions below 5
μ
m a e ob ained, shown in
Fig. 1c. This beha io is also obse ed in he c oss-sec ion image
(Fig. 1d) and is explained by he polyme /sol en phase diag am, he
po ous s uc u e being de e mined by he ini ial polyme concen a ion
in solu ion and he sol en e apo a ion empe a u e [26], leading, wi h
he used p ocessing condi ions, o a liquid −liquid phase sepa a ion
p ocess ha p oduces he po ous mo phology.
Fig. 1e-– –show he SEM images o he memb anes ob ained by he
sal -leaching me hod in su ace and c oss-sec ion, espec i ely. A
mo phology wi h an i egula po ous s uc u e is also ob ained due o
he elimina ion o he sal du ing he p epa a ion me hod.
Fo he elec ospinning echnique, wo SEM images o he su ace,
wi h di e en magni ica ions, a e shown in Fig. 1g–h, whe e a ibe
s uc u e wi hou beads is obse ed. Fu he mo e, his mic os uc u e is
based on ibe s wi h egula size and a diame e o 600 ±100 nm.
The deg ee o po osi y o he P(VDF-T FE-CFE) memb anes was
de e mined using me cu y in usion po osime y (MIP) and he ob ained
alues a e p esen ed in Table 1. I is obse ed ha he deg ee o po osi y
a ies om 23 % o he memb anes ob ained by SL o 66 % o he ones
ob ained by TIPS, in co ela ion wi h he mic os uc u e o he mem-
b anes. Fig. 2 shows he loga i hm o he cumula i e in uded olume as
a unc ion o po e size diame e o he di e en P(VDF-T FE-CFE)
memb anes. A wide ange o di e en po es sizes is obse ed o mos
o he memb anes, in co ela ion wi h he SEM images (Fig. 1).
The memb anes p epa ed by TIPS show a la ge dis ibu ion o po e
Fig. 1. SEM images o he memb anes ob ained by di e en p ocessing echniques: a) NIPS su ace b) NIPS c oss sec ion; c) TIPS su ace d) TIPS c oss sec ion; e) SL
su ace ) SL c oss sec ion; g) ES su ace and h) ES c oss-sec ion.
Table 1
Po osi y, β-phase con en , deg ee o c ys allini y, Young modulus and yield s ess and s ain alues o all P(VDF-T FE-CFE) memb anes p ocessed by di e en
echnique.
Samples Po osi y/±5 % β-phase/±2 %
χ
c
/±1 % E’/±40 MPa Yield s ess/±0.5 MPa Yield s ain/±2 %
NIPS 24 83 11 131 1.5 22
TIPS 66 84 12 119 1.1 18
ES 56 84 9 17 0.2 14
SL 23 85 12 48 0.5 19
Fig. 2. In uded cumula i e olume as a unc ion o po e size o he
di e en memb anes.
R.S. Pin o e al. Jou nal o Colloid And In e ace Science 680 (2025) 714–724
717
sizes, ollowing by he ones p epa ed by ES and NIPS. In ela ion o he
memb anes p oduced by SL, hey p esen he smalles dis ibu ion o
po e sizes.
Conside ing ha memb ane sh inkage is an impo an ac o in
ba e y sys ems, Fig. 3a) shows pho og aphic images o he TIPS mem-
b ane be o e and a e he mal ea men a 100 ◦C o 1 h. Fo o he
memb anes, he beha io is simila . Fig. 3a) shows ha he memb anes
show high he mal s abili y, no showing any ele an sh inkage a e
he he mal ea men .
Fig. 3b) and c) show he con ac angle o he di e en memb anes in
wa e and elec oly e solu ion, espec i ely. Fo wa e (Fig. 3b), i is
obse ed ha he con ac angle is g ea e han 78◦, demons a ing he
hyd ophobic cha ac e o his polyme [32]. The obse ed di e ences in
con ac angle be ween he memb anes is ully ela ed o he di e ences
Fig. 3. a) Pho og aphic images o TIPS memb ane be o e and a e he mal ea men a 100 ◦C o 1h. b) and c) con ac angle o he di e en memb anes wi h wa e
and elec oly e solu ion, espec i ely.
Fig. 4. a) FTIR spec a, b) DSC and c) TGA he mal cha ac e is ics and d) s ess–s ain mechanical cu es o he P(VDF-T FE-CFE) memb anes.
R.S. Pin o e al. Jou nal o Colloid And In e ace Science 680 (2025) 714–724
718
in mo phology.
Fig. 3c) shows he con ac angle o he memb anes o elec oly e
solu ion, he con ac angle being less han 57 ◦. Fo he ES memb ane,
he elec oly e d ople is immedia ely abso bed due o i s mo phology.
Thus, good we abili y o he P(VDF-T FE-CFE) memb anes by he
elec oly e is demons a ed, due o he compa ibili y be ween polyme
su ace and he o ganic sol en s in he elec oly e solu ion. This will
allow e icien pa hs o mig a ion o Li
+
ions ac oss he memb ane.
3.2. In a ed spec a, he mal and mechanical cha ac e is ics
The polyme phases p esen in he P(VDF-T FE-CFE) memb anes
ob ained h ough di e en p ocessing echniques we e e alua ed by
Fou ie ans o m in a ed spec oscopy (FTIR) and he espec i e
spec a is shown in Fig. 4a.
Rega dless o he p ocessing echnique, Fig. 4a shows he cha ac-
e is ic bands o he P(VDF-T FE-CFE) polyme a 841 and 1400 cm
−1
,
ela ed o he pola β-phase o he polyme , and CH
2
and CF
2
ocking and
CF
2
an isymme ic s e ching ib a ion bands, iden i ied wi h an a ow
in his igu e [26].
The quan i ica ion o β-phase (F(β)) o he memb anes was ob ained
h ough Eq. (6) [33]:
F(β) = Aβ
(Kβ
K
α
)A
α
+Aβ
(6)
whe e he abso bances A
α
and Aβa 766 and 840 cm
−1
co espond o he
α
o βphases, espec i ely, and K
α
and K
β
a e he co esponding ab-
so p ion coe icien s, 6.1 ×10
4
and 7.7 ×10
4
cm
2
.mol
−1
.
The β-phase (F(β)) con en o di e en memb anes is summa ized in
Table 1, showing alues ~84 % o all he samples, independen ly o he
p ocessing echnique. Thus, he chemical composi ion o he e polyme
and he low empe a u e p ocessing de e mine he speci ic phase con-
en in he samples [25].
The he mal beha io o he di e en P(VDF-T FE-CFE) memb anes
was e alua ed by he DSC (Fig. 4b) and TGA (Fig. 4c). Independen ly o
he p ocessing echnique, he DSC hea ing he mog ams o he mem-
b anes (Fig. 4b) show wo endo he mic peaks a ~50 ◦C and 124 ◦C, o
all samples, ela ed o he o he e oelec ic-pa aelec ic phase an-
si ion and he mel ing empe a u e, espec i ely [26].
None heless, an addi ional peak abo e 124 ◦C is obse ed o all
memb anes, excep ing he ones p epa ed by TIPS, ela ed o he mel ing
o c ys als o di e en sizes [34].
The deg ee o c ys allini y alue o he di e en memb anes was
calcula ed by Eq. (7):
χ
c=ΔH
xΔH
α
+yΔHβ
(7)
whe e ΔH is he mel ing en halpy, x and y ep esen he
α
and βphase
con en o each sample, as calcula ed om he FTIR esul s, and ΔH
α
and
ΔH
β
a e he mel ing en halpies o he
α
(93.07 J.g
−1
) and βphase (103.4
J.g
−1
) o PVDF [35], espec i ely.
The deg ee o c ys allini y alues o he P(VDF-T FE-CFE) mem-
b anes is p esen ed in Table 1, showing ha i is p ac ically cons an
Fig. 5. a) Elec oly e up ake p ocess, b) Nyquis plo a oom empe a u e o he P(VDF-T FE-CFE) memb anes. c) CV cu e and d) DC pola iza ion measu emen s
o he P(VDF-T FE-CFE) memb ane p oduced by sal leaching.
Table 2
Ionic conduc i i y (
σ
i), o uosi y (
τ
), MacMullin numbe (N
M
) and li hium
ans e ence numbe (
Li
+
) alues o he di e en po ous memb anes.
Samples
σ
i
/mS.cm
−1
τ
N
M
Li
NIPS 0.4 2.6 29 0.2
TIPS 0.2 6.2 58 0.55
ES 1.8 1.9 6.4 0.37
SL 0.4 2.6 29 0.55
R.S. Pin o e al. Jou nal o Colloid And In e ace Science 680 (2025) 714–724
719
(9–12 %) o all memb anes, independen ly o he p ocessing condi ions.
The low c ys allini y is due o he p esence o he T FE and CFE
monome s which educe he deg ee o c ys allini y in ela ion o he
PVDF polyme [36].
Fig. 4c shows he TGA cu es o he di e en P(VDF-T FE-CFE)
memb anes. Rega dless o he p ocessing echnique, a single deg ada-
ion s ep is obse ed a ~455 ◦C ela ed o he scission o ca bon –
hyd ogen (C
–
H) bonds in he polyme chains [26].
The mechanical p ope ies we e e alua ed by ensile s ess–s ain
measu emen s as shown in Fig. 4d, whe e po osi y plays an impo an
ole in he mechanical esponse, since he deg ee o c ys allini y is
p ac ically he same o all memb anes, as e i ied by DSC analysis.
Rega dless o he p ocessing echnique, Fig. 4d shows he ypical me-
chanical beha io o a he moplas ic polyme wi h elas ic and plas ic
egions and yield poin [36].Table 1 shows he Young’s modulus
calcula ed om he secan me hod a 3 % o s ain and yield s ess and
s ain o all memb anes. I is obse ed ha he memb ane p ocessed by
NIPS is he one wi h he highes Young’s modulus, accompanied by a
low deg ee o po osi y. None heless, he memb ane p oduced by SL also
shows a low deg ee o po osi y bu he lowes Young modulus, due o he
i egula po ous mo phology. Fu he mo e, he elec ospun memb anes
exhibi lowe mechanical beha io due o he ibe s uc u e. Despi e he
di e en mechanical p ope ies obse ed, all memb anes can be used as
sepa a o s in li hium-ion ba e y applica ions [37].
3.3. Up ake and elec ochemical cha ac e iza ion
Elec oly e up ake, ionic conduc i i y alue and elec ochemical
s abili y o he sepa a o s a e essen ial cha ac e is ics o ba e y ap-
plica ions. The abso p ion o elec oly e depends on he mo phology and
also on he in e ac ions be ween he elec oly e solu ion and he po ous
memb ane, in which good we abili y co ela es wi h good anspo
beha io [38].
Fig. 5a shows he elec oly e up ake beha io o all P(VDF-T FE-
CFE) memb anes, he p ocessing echnique and, he e o e, mic os uc-
u e o he memb anes s ongly a ec s his beha io . Independen ly o
he p ocessing echnique, he up ake p ocess is comple ely s abilized
a e 250 s. Fu he mo e, i is obse ed ha his beha io does no
depend on he deg ee o po osi y, bu a he on he size and s uc u e o
he po es (Fig. 5a) and Fig. 1).
The memb ane wi h highes elec oly e up ake is he one p oduced
by elec ospinning, due o he ibe s uc u e and he co esponding high
su ace a ea o in e ac ing wi h he elec oly e. Fu he mo e, his
beha io is simila o he memb ane ob ained by SL, due o he p esence
o la ge po es in his memb ane and low po osi y alue.
Fo he o he echniques (NIPS and TIPS), a simila e ec is obse ed.
All mo phologies p esen emp y po es wi h small size and di e en
po osi y alue. Fu he , he elec oly e also en e s wi hin he amo phous
phase and, he e o e, a ec s he up ake p ocess.
Sepa a o -elec oly e in e ac ions a e c i ical o li hium anspo
beha io , a ec ing ionic conduc i i y and li hium ans e ence numbe .
Fig. 5b shows he Nyquis plo a oom empe a u e o he P(VDF-T FE-
CFE) memb anes. F om Fig. 5b and Eq. (2), he ionic conduc i i y alue
is calcula ed h ough he bulk esis ance and he co esponding alues
a e shown in Table 2.
Independen ly o he p ocessing echnique, he Nyquis plo p esen a
s aigh line ela ed o he cha ge ans e p ocess, indica ing high ionic
conduc ion [39].
Table 2 shows he ionic conduc i i y alue o he P(VDF-T FE-CFE)
memb anes and a co ela ion is obse ed be ween he elec oly e up ake
Fig. 6. a) 5 h Cha ge/discha ge p o iles a di e en C- a es o P(VDF-T FE-CFE) memb anes p oduced by TIPS, b) 10 h cha ge/discha ge p o ile a 2C- a e o all P
(VDF-T FE-CFE) memb anes, c) a e pe o mance and d) cycle li e beha io o he P(VDF-T FE-CFE) memb anes.
R.S. Pin o e al. Jou nal o Colloid And In e ace Science 680 (2025) 714–724
720
and he ionic conduc i i y, i.e, he memb anes wi h he highes elec-
oly e up ake alue show a highe ionic conduc i i y. The highes ionic
conduc i i y (1.8 mS.cm
−1
) is ob ained o he elec ospun memb anes,
esul ing om i s ib ous s uc u e wi h high in e nal su ace a ea, ha
p omo es he bes in e ac ion be ween elec oly e solu ion and he
polyme memb ane. The lowes ionic conduc i i y alue o 0.2 mS.cm
−1
is obse ed o he memb ane p oduced by TIPS, due o he low elec-
oly e up ake capaci y.
Table 2 also p esen s he o uosi y (
τ
) and MacMullin numbe (N
m
)
pa ame e s ob ained om Eqs. (3) and (4), espec i ely. Fo bo h pa-
ame e s, a co ela ion is obse ed wi h he ionic conduc i i y alue, a
low o uosi y alue (
τ
=1.9) being ob ained o he elec ospun
memb ane. I is o no ice ha his alue is close o he ideal o uosi y
alue (
τ
=1) and oge he wi h he high ionic conduc i i y, indica e an
excellen ion anspo pa h o his mo phology [40].
Mo eo e , he MacMullin numbe (N
M
) o he memb anes ange
be ween 6.4 and 58.0, alues ob ained o he memb anes p oduced by
elec ospinning and TIPS, espec i ely. The low N
M
alue is due o he
highe ionic conduc i i y alue. This alue is lowe han he alues
ob ained o comme cial sepa a o s [40], which is adequa e o ob ain
excellen cycling beha io .
The elec ochemical s abili y o he memb anes was e alua ed by
oom empe a u e CV measu emen s, as shown in Fig. 5c o he mem-
b ane p epa ed by SL in o de o e alua e he oxida ion (ini ial sweep in
he posi i e di ec ion) and educ ion p ocess ( e e se sweep in a nega-
i e di ec ion). This cu e is ep esen a i e o he es o he mem-
b anes. Analyzing Fig. 4c, i is obse ed ha he cu en alue is below
10
−8
A wi h good elec ochemical s abili y be ween 0.0 and 4.5 V s Li/
Li
+
wi hou anodic peaks. The alue o he small educ ion peaks
obse ed does no a ec i s s abili y.
DC pola iza ion measu emen s we e pe o med o e alua e he
li hium-ion ans e ence numbe ,
Li
+
, as shown in Fig. 5d. Fig. 5d shows
hese measu emen s o he P(VDF-T FE-CFE) memb ane p oduced by
SL, which is ep esen a i e o he o he memb anes.
Li
+
was calcula ed
using he B uce and E ans me hod [28,29] and he alues a e p esen ed
in Table 2, which shows no co ela ion be ween elec oly e up ake and
Li
+
alues o he di e en memb anes. Also, a high
Li
+
is de ec ed o he
memb anes p epa ed by SL and TIPS wi h lowe ionic conduc i i y
alue, whe e hei mo phology and po e size play an impo an ole in
his beha io . Fu he mo e, he ob ained alues o he memb anes
p oduced by hese echniques a e highe compa ed o he ones o
comme cial polye hylene sepa a o [41].
3.4. Ba e y pe o mance
Hal cells wi h LFP based elec odes we e p oduced wi h he di e en
P(VDF-T FE-CFE) memb anes o e alua e he oom empe a u e cha -
ge–discha ge beha io be ween 2.5 and 4.2 V, be ween C/8 and 2C-
a es. Fo each C- a e and P(VDF-T FE-CFE) memb ane, en cha -
ge–discha ge cycles we e pe o med. Fig. 6a shows he cycling p o ile o
he ba e y wi h P(VDF-T FE-CFE) memb anes p oduced by TIPS a C/8,
C/5, C/2, 1C and 2C a es, he p esen ed p o ile co esponding o he
en h cycle o each a e. Fo he es o he memb anes he p o ile is
iden ical o hose obse ed in Fig. 6a.
Fo all C- a es, Fig. 6a p esen s he anodic/ca hodic peaks ela ed o
he LFP elec ode ha ep esen he li hium inse ion in he discha ge
p ocess and he li hium emo al in he cha ging p ocess, espec i ely.
Fu he mo e, i is obse ed a la cha ge–discha ge pla eau a ound
3.2–3.6 V, co esponding o he Fe
2+
/Fe
3+
edox eac ion [42]. Fu he ,
i is de ec ed ha he pla eau po en ial and he capaci y alue dec ease
when he C- a e inc eases due o he pola iza ion beha io inside he
ca hode elec ode [43]. The discha ge capaci y alue o he P(VDF-T FE-
CFE) memb ane p oduced by TIPS is 147 mAh.g
−1
, 141 mAh.g
−1
, 129
mAh.g
−1
, 86 mAh.g
−1
and 32 mAh.g
−1
a he C a es o C/8, C/5, C/2,
1C and 2C (Fig. 6a), espec i ely, demons a ing good ba e y pe o -
mance a di e en a es and excellen e e sibili y beha io due o he
high li hium ans e ence numbe o his memb ane.
In o de o assess he cha ge/discha ge p o ile o he di e en
memb anes, Fig. 6b shows he en h p o ile beha io a he 2C- a e. I is
obse ed ha he p ocessing echnique and he co esponding
mo phological a ia ion o he memb anes a ec s he cycle beha io
and he discha ge capaci ies a 2C- a e, which a e 44 mAh.g
−1
, 32 mAh.
g
−1
, 17 mAh.g
−1
and 17 mAh.g
−1
o SL, TIPS, ES and NIPS ob ained
memb anes, espec i ely. These di e en discha ge alues a e co e-
la ed wi h he li hium ans e ence numbe o he memb anes (Table 2),
being highe o memb anes wi h a highe li hium ans e ence numbe .
Fig. 6c shows he a e pe o mance o he di e en memb anes as a
unc ion o he numbe o cycles. Fo each a e and memb ane, he
discha ge capaci y alue emains cons an o he di e en numbe o
cycles.
Rega dless o he memb ane ype and he C- a e up o he C/5- a e, i
is obse ed ha he discha ge capaci y is s able o all memb anes. The
ES memb ane shows lowe discha ge capaci y compa ed wi h he o he
samples independen ly o he applied C- a e, which can be associa ed o
he high up ake alue compa ed o he o he samples. A C- a es abo e
C/2, di e en cycling beha io s a e obse ed o he memb anes ob-
ained by he di e en p ocessing echniques. Fo 2C a e, he highes
discha ge capaci y is obse ed o he memb ane p ocessed by SL due o
he highe li hium ans e ence numbe wi h espec o he o he
memb anes. Fig. 6c) shows he ba e y pe o mance a di e en C a ios
o he di e en P (VDF-T FE-CFE) memb anes compa ed wi h com-
me cial glass mic o ibe sepa a o s. I is obse ed ha he discha ge
alue o P(VDF-T FE-CFE) memb anes p oduced by SL and NIPS is
highe compa ed o he glass mic o ibe sepa a o .
This beha io is also demons a ed in Fig. 6d o he cycling s abili y
e alua ion a C- a e o 100 cycles, whe e he combina ion o di e en
Fig. 7. Elec ochemical impedance spec oscopy o he P(VDF-T FE-CFE) memb anes: a) be o e and b) a e cycling p ocess.
R.S. Pin o e al. Jou nal o Colloid And In e ace Science 680 (2025) 714–724
721
pa ame e s o he sepa a o , such as he deg ee o po osi y, ionic con-
duc i i y alue and li hium ans e ence numbe a e essen ial in cycling
beha io . Fo he i s cycles, i is de ec ed ha he discha ge capaci y
dec eases, as he C- a e inc eases un il he C- a e is eached. A e 100
cycles a C- a e, he discha ge capaci y alues a e 74 mAh.g
−1
, 58 mAh.
g
−1
, 42 mAh.g
−1
and 42 mAh.g
−1
o SL, NIPS, TIPS and ES, espec-
i ely, wi h low capaci y ade and excellen coulombic e iciency o ~99
% o all samples, ela ed o he excellen we abili y o he elec oly e
solu ion and i s compa ibili y wi h he polyme memb ane.
To e alua e he e ec o he di e en memb anes on ba e y pe -
o mance, impedance spec oscopy measu emen s we e pe o med
be o e (Fig. 7a) and a e (Fig. 7b) cycling, as ep esen ed by he co -
esponding Nyquis plo s.
Fig. 7 shows ha he Nyquis plo s o all samples is cha ac e ized by
Ohmic esis ance a high equency, ep esen ed by a semici cle, and an
o e all esis ance ha co esponds o he cha ge- ans e esis ance a
he solid- ilm in e ace and li hium esis ance o ionic mig a ion a he
solid-elec oly e in e ace (SEI) in he medium equency ange [43]. A
low equency, an inclined line is obse ed ha ep esen s he Wa bu g
impedance ela ed o Li
+
di usion [43]. The co esponding equi alen
ci cui and he i ing o he cu es a e p esen ed in Fig. 7 [44,45]. In his
ci cui , wo esis ances a e ep esen ed (R1 and R2) which co espond o
he bulk esis ance ba e y in e nal esis ance, espec i ely. Addi ion-
ally, he e a e wo capaci o s (CPE
in e ace
and CPE
di usion
) ha co e-
spond o he capaci ance a high and low equencies, and he Wa bu g
elemen (W), ep esen ing he ion di usion phenomena [46]. Fu he ,
he alues o he di e en elemen s o he equi alen ci cui ob ained
a e i ing he expe imen al cu es a e shown in Table 3, be o e and
a e ba e y cycling.
Fig. 7a and Table 3 shows ha he o e all esis ance be o e cycling is
2198 Ω, 1425 Ω, 1302 Ωand 950 Ω o NIPS, TIPS, SL and ES ob ained
memb anes, espec i ely. A e cycling (Fig. 7b and Table 3), i is
obse ed ha he o e all esis ance alues dec ease due o he o ma ion
o he SEI laye du ing he cycling p ocess. The o e all esis ance alues
a e 585 Ω, 739 Ω, 999 Ωand 817 Ω o NIPS, SL, ES and TIPS ob ained
memb anes, espec i ely.
Rega dless he P(VDF-T FE-CFE) memb ane ype, i is de ec ed ha ,
a e cycling, he o e all esis ance is lowe compa ed o he esis ance
be o e cycling (Table 3), due o he excellen compa ibili y be ween he
sepa a o and he elec ode hin ing a good in e ace be ween hese
componen s. A simila beha io is obse ed o he capaci ance alue
(C), excep o he ES sample. The capaci ance alue ep esen s he ca-
paci y o he ba e y o s o e cha ge a he elec ode/elec oly e in e -
ace. This means ha highe capaci ance alues co espond o be e
su ace p ope ies. The high capaci ance alue o he SL co obo a es he
good pe o mance esul s, while he loss o capaci ance ollows he end
o lowe cycling s abili y a e a p olonged numbe o cycles o all
samples excep he ES one.
Table 4 compa es he main elec ochemical pa ame e s and
discha ge capaci y alue o he P(VDF-T FE-CFE) memb ane wi h
ela ed memb anes based on PVDF and i s copolyme s epo ed in he
li e a u e.
This is he i s ime ha his polyme ype has been epo ed as a
sepa a o memb ane o li hium-ion ba e y applica ions, and he ba -
e y pe o mance is compa able o o he PVDF polyme -based sepa a-
o s wi h special ele ance conside ing he excellen cycling beha io a
high C a e due o he low deg ee o c ys allini y.
The e o e, he p esen wo k demons a es ha i is possible o ob ain
high-pe o mance sepa a o s based on P(VDF-T FE-CFE) polyme s, he
p ocessing echnique allowing o ailo hei mo phology and, conse-
quen ly, elec ochemical pa ame e s and ba e y pe o mance. In his
sense, he memb ane p epa ed by sal leaching is he mos sui able o
his applica ion based on cycling beha io .
4. Conclusions
This wo k e alua ed he e ec o di e en p ocessing echniques
(non-sol en and he mally induced phase sepa a o , sal leaching and
elec ospinning) on he ba e y pe o mance o sepa a o memb anes
based on poly( inylidene luo ide-co- i luo oe hylene- chlo o luo o-
e hylene), P(VDF-T FE-CFE).
Using di e en p ocessing echniques, dis inc mo phologies we e
ob ained wi h a iable deg ees o po osi y and po e sizes, which a ec
he mechanical beha io and po osi y o he memb anes, which anges
om 24 % o 66 % o he memb anes ob ained by NIPS and TIPS
espec i ely.
The e a e no signi ican a ia ions in he polyme phase con en and
he mal cha ac e is ics o he di e en memb anes. The mechanical
p ope ies ollow he endency o he deg ee o po osi y wi h di e en
mo phologies since he deg ee o c ys allini y is p ac ically he same o
Table 3
Equi alen ci cui pa ame e s o he assembled ba e ies.
R1 (Ω) R2 (Ω) CPE (nF)
NIPS be o e 123 2075 0,63186
a e 62 523 0,59407
TIPS be o e 83 1342 0,6284
a e 57 760 0,62174
ES be o e 100 850 0,36203
a e 252 747 0,4968
SL be o e 58 1244 0,724
a e 62 677 0,50251
Table 4
PVDF based sepa a o memb anes in LIB applica ions.
Polyme ma ix Elec oly e Po osi y/Up ake
(%)
Ionic conduc i i y (mS.
cm
−1
)
Discha ge capaci y (mAh.
g
−1
)
Re
PVDF 1 M LiPF
6
in EC:DMC 64.5/303.8 1.2 [email p o ec ed] [47]
PVDF 1 M LiPF
6
in EC:DMC −/540 −[email p o ec ed] [48]
PVDF 1 M LiPF
6
in EC/DEC 20/100 0.23 56@2C [49]
PVDF 1 M LiPF
6
in EC/DMC/EMC −/−0.30 [email p o ec ed] [50]
PVDF-T FE 1 M LiPF
6
in EC:DMC 70/120 1.6 107@2C [51]
PVDF-T FE 1 M LiPF
6
in EC:DMC 70/262 3 85.5@2C [52]
PVDF-T FE 1 M LiPF
6
in EC:DMC 72/84 2.6 [email p o ec ed] [53]
PVDF-HFP 1 M LiPF
6
in EC:DMC 72/77 1.3 [email p o ec ed] [54]
PVDF-HFP 1 M LiPF
6
in EC/DEC 228.5/–−80@2C [55]
PVDF-HFP 1 M LiPF
6
in EC:DMC 78/86.2 1.03 [email p o ec ed] [56]
PVDF-CTFE 1 M LiTFSI in PC 60/275 1.5 92@2C [57]
PVDF-CTFE +Sb
2
O
3
1 M LiPF
6
in EC:DEC 72/356 2.88 167@1C [58]
P(VDF-T FE-CFE) p oduced by sal
leaching
1 M LiPF
6
in EC:DMC 24/342 0.4 94@C In his wo k
R.S. Pin o e al. Jou nal o Colloid And In e ace Science 680 (2025) 714–724
722
