Available via license: CC BY-NC-ND 4.0
Content may be subject to copyright.
Polyaspartate Polyurea-Based Solid Polymer Electrolyte with High
Ionic Conductivity for the All-Solid-State Lithium-Ion Battery
Lu Bai,
§
Peng Wang,*
,§
Chengyu Li, Na Li,*Xiaoqi Chen, Yantao Li, and Jijun Xiao*
Cite This: ACS Omega 2023, 8, 20272−20282
Read Online
ACCESS Metrics & More Article Recommendations *
sı Supporting Information
ABSTRACT: The existing in situ preparation methods of solid
polymer electrolytes (SPEs) often require the use of a solvent,
which would lead to a complicated process and potential safety
hazards. Therefore, it is urgent to develop a solvent-free in situ
method to produce SPEs with good processability and excellent
compatibility. Herein, a series of polyaspartate polyurea-based
SPEs (PAEPU-based SPEs) with abundant (PO)x(EO)y(PO)z
segments and cross-linked structures were developed by system-
atically regulating the molar ratios of isophorone diisocyanate
(IPDI) and isophorone diisocyanate trimer (tri-IPDI) in the
polymer backbone and LiTFSI concentrations via an in situ
polymerization method, which gave rise to good interfacial
compatibility. Furthermore, the in situ-prepared PAEPU-SPE@
D15 based on the IPDI/tri-IPDI molar ratio of 2:1 and 15 wt % LiTFSI exhibits an improved ionic conductivity of 6.80 ×10−5S/cm
at 30 °C and could reach 10−4orders of magnitude when the temperature was above 40 °C. The Li|LiFePO4battery based on
PAEPU-SPE@D15 had a wide electrochemical stability window of 5.18 V, demonstrating a superior interface compatibility toward
LiFePO4and the lithium metal anode, exhibited a high discharge capacity of 145.7 mAh g−1at the 100th cycle and a capacity
retention of 96.8%, and retained a coulombic eciency of above 98.0%. These results showed that the PAEPU-SPE@D15 system
displayed a stable cycle performance, excellent rate performance, and high safety compared with PEO systems, indicating that the
PAEPU-based SPE system may play a crucial role in the future.
1. INTRODUCTION
Lithium-ion batteries (LIBs) have brought astonishing
advancements and transformations in portable electronics
and, more recently, electric vehicles during the past several
decades.
1,2
With the rapidly expanding market of electric
vehicles, storage systems with high energy density are in strong
demand.
3−6
However, there are some serious safety issues such
as short circuits, leakage, and combustion, even explosions,
derived from the dendrite growth in liquid electrolytes.
7−9
Motivated by this challenge, many types of research such as
solid-state inorganic electrolytes and solid polymer electrolytes
(SPEs) have drawn significant attention.
10−15
The former
mainly includes sulfide-based electrolytes and oxide-based
electrolytes, which are brittle and have high interfacial
resistance owing to poor contact with electrodes. In contrast,
SPEs, blessed with a high flexibility and more safety, enable the
application of a high-capacity Li−metal anode in which the
possibility of internal short-circuiting by the penetration of
dendritic Li can be suppressed. Consequently, SPEs may be
the ultimate path to the batteries of the future.
16−18
Most polymers have been recently exploited to dissolve
lithium salts in these polymers for constructing SPEs, such as
poly(ethylene oxide) (PEO), polyacrylonitrile (PAN), poly-
(vinylidene fluoride) (PVDF), poly(methyl methacrylate)
(PMMA), and so on, in order to eectively enhance the
performance of solid polymer electrolytes.
19−26
Especially, the
SPE based on PEO is the most extensively investigated of
polymer hosts for an ecient Li-salt dissolvability through the
interaction of its ether oxygen bonds with cations. For all of the
above reasons, numerous strategies have been reported to
improve the ion conductivities of SPEs, including block-
ing
27−30
and grafting modification,
31,32
adding plasticizers,
33,34
polymer blending,
35,36
or forming the cross-networking.
37,38
Besides, many polymers containing abundant EO structure
units have also been studied as matrices of SPEs.
39−43
In
particular, the preparation methods of solid polymer electro-
lytes can influence the interface impedance. In addition to
solution casting,
44,45
phase transformation,
46−48
and electro-
static spinning,
49,50
many researchers also often use in situ
polymerization,
51−53
light curing methods,
54,55
and the scalable
Received: November 16, 2022
Accepted: April 11, 2023
Published: May 31, 2023
Article
http://pubs.acs.org/journal/acsodf
© 2023 The Authors. Published by
American Chemical Society 20272
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
tape-casting method
56
to prepare solid polymer electrolytes.
Zhao’s research group
57
added the polymer matrix cellulose
acetate (CA), the cross-linking agent poly(ethylene glycol
diacrylate) (PEGDA), and the initiator AIBN to the liquid
electrolyte, which consists of lithium hexafluorophosphate
(LiPF6), ethylene carbonate (EC), and diethyl carbonate
(DEC); then, the layered boron nitride (BN) filler was added
to the above mixture, and a cross-linked gel polymer electrolyte
(GPE) was prepared by in situ thermal polymerization. The
cross-linked GPE exhibits good mechanical and electro-
chemical properties, with an ionic conductivity of 8.9 ×10−3
S cm−1at 30 °C and an electrochemical stability window of 5.5
V. Drews et al.
58
reported that the PIL brush-type GPE with
PEtOx side chain was prepared by ultraviolet (UV) irradiation
of a cationic vinylimidazolium-terminated poly(2-ethyl-2-
oxazoline) (PEtOx) macromonomer and a multifunctional
acrylic cross-linking agent dissolved in an organic electrolyte
(LP30). In situ and ex situ preparation methods are used
according to dierent characterizations, and the PIL brush
GPE has good ionic conductivity, thermal properties, and
electrochemical stability. Notwithstanding the organic solvents
used in some systems of these gel electrolytes will be removed
in subsequent operations,
59
the residual solvents may lead to
side reactions with the electrodes. Apart from that, the residual
organic solvents also increase the risk when working at higher
temperatures, leading to safety issues that cannot be
guaranteed. Consequently, it is necessary to develop a
solvent-free solid electrolyte with EO structure.
Polyaspartate polyurea (PAEPU) is a kind of polymer rich in
the ether oxygen group with good viscoelasticity and
processing flexibility. The abundant ether oxygen groups
endow it with a similar conduction mechanism to that of PEO.
In addition, the raw materials are cheap and easy to obtain, and
the preparation process of PAEPU is simple and does not need
any organic solvent. These merits provide PAEPU the
potential for use as a matrix of SPEs.
Herein, a solvent-free cross-linked PAEPU-based electrolyte
with polyaspartic ester (PAE) and polyisocyanates as the main
components was prepared by the in situ thermal polymer-
ization method. Previously, the product of PAE and
polyisocyanates was mostly used in the adhesive field,
60−62
but its use as an electrolyte has been scarcely reported.
However, the PAEPU-based SPE membrane is expected to
function as a novel electrolyte due to the following features: (i)
the abundant ether oxygen bonds and low crystallinity are in
favor of the transport of Li+; (ii) formation of an integrated
interface by in situ polymerization and strong adhesion to both
electrodes; and (iii) the flexible and elastic properties can be
tuned to accommodate the volume change originating from the
anode. Besides, we are interested in a polymer matrix with a
dierent cross-linking density; consequently, five dierent
mole ratios of difunctional (isophorone diisocyanate (IPDI))
and trifunctional diisocyanate (isophorone diisocyanated
trimer (tri-IPDI)), respectively, abbreviated as PAEPU-SPE@
Rn, are employed in this study. Here, R refers to A, B, C, D,
and E, which reflect the dierent mole ratios of IPDI to tri-
IPDI (the ratios are 0:1, 1:2, 1:1, 2:1, and 3:1, respectively),
and n refers to the mass concentrations (0, 5, 15, and 25 wt %)
of LiTFSI, which are based on the mass of PAE. The thermal
and electrochemical properties of the solvent-free solid-state
polymer electrolyte were systematically studied. The results
show that the PAEPU-based SPE has good stability and a wide
electrochemical stability window, and there is low interface
impedance between the electrode and electrolyte due to the in
situ polymerization method. Beyond the obvious benefits
already discussed, the electrolytes show outstanding compre-
hensive properties, and the cells assembled with the electro-
lytes exhibit superior electrochemical performances.
2. EXPERIMENTAL SECTION
2.1. Materials. Polyetheramine (ED2003 Mw≈2000) was
purchased from Shandong Mole Chemical Co., Ltd. Diethyl
maleate (DM) was purchased from Guangzhou Yuanda New
Material Co., Ltd. Isophorone diisocyanate (IPDI) was
purchased from Wuhan Kanos Technology Co., Ltd.
Isophorone diisocyanated homopolymer (IPDI-trimer) was
purchased from Jining Huakai Resin Co., Ltd. Lithium
bis(trifluoromethanesulfonyl)imide (LiTFSI) was purchased
from Aladdin (Shanghai, China) and used as received. N-
methylpyrrolidone (NMP), lithium iron phosphate (LiFePO4),
Scheme 1. Synthesis of PAEPU-Based SPE
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20273
poly(vinylidene fluoride) (PVDF), and carbon black (Super P)
were procured from Guangdong Canrd New Energy
Technology Co., Ltd.
2.2. Preparation of PAE. The PAE was synthesized
through the Michael reaction using ED2003 and DM. Into a
four-necked flask was added ED2003 (50 g, 0.025 mol) with
stirring and using a thermometer; then, DM was added
dropwise (8.61 g, 0.05 mol) under N2atmosphere; the
temperature of the mixture was kept below 60 °C during the
dripping process. Subsequently, the mixture was heated to 80
°C and stirred at this temperature for 24 h.
2.3. Preparation of PAEPU-Based SPEs. PAE was mixed
with dierent contents of LiTFSI at 60 °C for 12 h to obtain
the mixed solution of PAE/LiTFSI in a dried N2atmosphere.
The PAE/LiTFSI mixture was reacted with a stoichiometric
amount of polyisocyanates in a Teflon beaker by magnetic
stirring for about 10 min. Subsequently, the final solution was
cast onto a PP board using a scraper. After reacting in a dry
environment at 60 °C for at least 12 h, a series of soft and
viscoelastic PAEPU-based SPEs was prepared. The thickness of
PAEPU-based SPEs was about 150 μm.
Dierent preparation processes were selected according to
the characterization methods: (1) In order to carry out
Fourier-transform infrared (FT-IR), scanning electron micros-
copy (SEM), energy dispersive X-ray spectroscopy (EDS), X-
ray diraction spectroscopy (XRD), dierential scanning
calorimetry (DSC), and thermogravimetric analysis (TGA)
characterization, an evenly mixed electrolyte was coated on a
dry flat polypropylene plate with a scraper, placed at room
temperature for 5 h, and then transferred to a vacuum oven at
60 °C for 24 h; after curing, the electrolyte was transferred to a
nonstick paper for storage. (2) For the rheological property
test, the evenly mixed electrolyte was directly coated on the
parallel-plate clamp for testing. (3) In order to test the ionic
conductivity, electrochemical stability window, ion migration
number, interface stability, cycle life, rate performance, and
application, the uniformly mixed electrolyte was directly
polymerized in situ on stainless steel, lithium, or cathode
plates. The synthesis of PAEPU-based SPE is shown in Scheme
1.
2.4. Assembly of the Symmetrical, Unsymmetrical,
and Half Cells. For electrochemical testing, the batteries are
divided into several types to assemble. Symmetric batteries are
used in the AC impedance test; a solid polymer electrolyte
(SPE) caught in the middle of a stainless steel shrapnel (SS) or
metallic lithium pills (Li) forms the “sandwich” structure: SS/
SPE/SS or Li/SPE/Li, respectively. Asymmetric batteries
assembled with Li/SPE/SS are used in the linear sweep
voltammetry test. The half-cell assembled with Li/SPE/
LiFePO4is utilized for testing the other batteries’ performance.
All types of cells were assembled with the CR2032 coin type in
a glovebox (H2O < 0.1 ppm, O2< 1 ppm) under Ar
atmosphere. In addition, the preparation of the LiFePO4
cathode is described in Supporting Information.
2.5. Characterization. The structures of the PAE and the
PAEPU-based SPE were tested by Fourier-transform infrared
spectroscopy (FT-IR IRL280301, Perkin Elmer) from 650 to
4000 cm−1and 1H NMR spectroscopy (Avance III HD
400MHz, Bruker, Germany), which used deuterated chloro-
form (CDCl3) as the standard solvent. The dynamic process of
the PAEPU-based SPE at 60 °C with an angular frequency of
10 rad/s was determined through the small-amplitude time
scanning mode in the rotary rheometer (DHR-1, TA)
oscillation test. The mechanical behavior of the PAEPU-
based SPE was characterized using a small-amplitude
frequency scanning mode in a rotary rheometer oscillation
test with a 25 mm aluminum parallel-plate geometry at 80 °C,
and the frequency sweeps were performed at a controlled strain
of 1.0% from 500 to 0.1 rad/s. The surface morphologies of the
SPE were investigated using a scanning electron microscope
(SEM) (Inspect-S50, FEI). The surface element distribution of
the SPE was characterized by energy dispersive X-ray
spectroscopy (EDS) (EDAX APOLLP XL, AMETEK) and
the crystallinity change of the SPE was analyzed by X-ray
diraction spectroscopy (XRD) (D/MAX-2500, Rigaku,
Japan) in the diraction angle range from 2 to 100°. The
thermal transition of the SPE was measured by dierential
scanning calorimetry (DSC) (Germany Netzsch DSC 214)
with a scan rate of 20 °C/min under N2atmosphere from
−100 to 100 °C. The thermal properties of the SPE were
measured by thermogravimetric analysis (TGA) (Q50, TA)
under N2atmosphere at a heating rate of 20 °C/min.
Ionic conductivity is one of the most important properties of
lithium batteries, which is calculated by
=
d
R S
b
, where dis the
thickness of the PAEPU-based SPE, Rbis the bulk resistance,
and Sis the eective area. Rbwas obtained by electrochemical
impedance spectroscopy (EIS) in the frequency range of 106−
1 Hz with an amplitude of 10 mV.
The electrochemical stability window was measured by
linear sweep voltammetry (LSV), with the voltage ranging
from 2 to 6 V at a scanning rate of 10 mV/s. The lithium-ion
transference number (tLi+) of the PAEPU-based SPE was
evaluated by the formula
=
+
tI R V I R
I R V I R
( )
( )
Li
sb
s 0 i0
0b
0 s is
. The cell was
polarized by a DC voltage (ΔV) at 10 mV, and the initial (I0)
Figure 1. (a) FT-IR and (b) 1H NMR spectra of PAE, DM, and ED2003. (c) FT-IR spectra of PAEPU-SPE@Cn(n= 0, 5, 15, 25).
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20274
and steady-state (Is) currents were measured. In this formula,
Rb
0and Rb
sare the bulk resistances before and after the
polarization; Ri
0and Ri
sare the corresponding interface
resistances before and after the polarization. All of the
resistances were acquired by EIS over a frequency ranging
from 106to 10−1Hz with an amplitude of 10 mV.
To evaluate the interfacial stability and compatibility of the
PAEPU-based SPE and lithium metal, an Li/PAEPU-based
SPE/Li lithium symmetric battery system was assembled to
monitor the change of interface impedance over time. The
interface resistances were acquired by EIS with a 10 mV
amplitude over the frequency ranging from 106to 1 Hz.
The cycling performance of the Li/PAEPU-based SPE/LFP
half-cell was determined with a voltage range of 2.5−3.8 V and
a current density of 0.5C at 60 °C using a battery tester
(CT2001A, LANHE System, China). The rate capabilities of
the Li/PAEPU-based SPE/LFP half-cell were determined in
the voltage range of 2.5−3.8 V at current densities of 0.1C,
0.2C, 0.5C, 1C, and 2C, respectively, at 60 °C using a LAND
battery tester.
3. RESULTS AND DISCUSSION
3.1. FT-IR and 1H NMR Characterization. The structure
of PAE was identified by FT-IR and 1H NMR spectra. In the
FT-IR spectra (Figure 1a), an absorption peak corresponding
to C−O−C was observed at 1094 cm−1, while the absorption
at 1639 cm−1attributed to the C�C in the DM disappeared,
verifying the formation of PAE. Moreover, the 1H NMR
spectrum of PAE showed a peak at 3.68 ppm (Figure 1b)
assigned to the proton of −CH2O−, and the peak at 6.28 ppm
assigned to the protons of −CH�CH−in DM disappeared.
Figure 1c shows the FT-IR spectra of PAEPU-SPE@Cn(n=
0, 5, 15, 25). New absorption peaks of S�O and C−F were
observed at 1058 and 1190 cm−1, respectively; the absorption
corresponding to the C−O−C in the main chain was observed
at about 1094 cm−1, in which the abundant ether oxygen
groups (−C−O−C−) were conducive to lithium-ion trans-
mission. The absorption of C−O−C in PAE with lithium salt
drifted toward 1090 to 1092 cm−1. The resulting data are due
to the interaction between Li+and C−O−C, that is, the
Figure 2. (a) Modulus−time curve of PAEPU-SPE@R15. (b) Modulus−frequency curve of PAEPU-SPE@R15.
Figure 3. SEM images and EDS mapping images of PAEPU-based SPE. (a−e) SEM images of PAEPU-SPE@R15. (f−i) SEM images of PAEPU-
SPE@Dn(n= 0, 15). (j−k) EDS mapping images of PAEPU-SPE@D15.
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20275
formation of ion-dipole complexation, resulting in the C−O−
C stretching band shifting to a low wavenumber. This
phenomenon is also often observed in the PEO system.
63
3.2. Viscoelastic Behavior. Take PAEPU-SPE@R15 as an
example. Figure 2 shows the viscoelastic behavior of PAEPU-
based SPEs. The storage modulus (G′) and the loss modulus
(G″), which denote the elastic and viscous properties of
PAEPU-SPE@R15, respectively, were tested using a rheometer
at a certain temperature. Figure 2a shows the dynamic changes
of the modulus for PAEPU-SPE@R15 with the reaction time at
60 °C and 10 rad/s. As the reaction time increases, G′and G″
increase, indicating that PAEPU-SPE@R15 forms gradually. At
the beginning of the reaction, G″is obviously larger than G′,
demonstrating that the viscous property dominates the
behavior of PAEPU-SPE@R15, and PAEPU-SPE@R15 behaves
more like a viscous liquid. G′even exceeds G″up to one or
two orders of magnitude after reaching the intersection of G′−t
and G″−tcurves, at which point PAEPU-SPE@R15 exhibits
more elastic behaviors. As time continues, G′and G″gradually
tend to be stable, indicating that the reaction is basically over.
The time taken to reach the intersection of G′−tand G″−t
curves becomes short with the increase of tri-IPDI content,
indicating that the cross-links inside PAEPU-SPE@R15 are
crucial for determining its behavior.
The SPE with viscoelastic properties is favorable for the even
deposition of metallic lithium, and prevent the formation of
lithium dendrite. Therefore, the oscillatory shear rheology of
PAEPU-SPE@R15 was studied to understand the viscoelastic
properties. Results from oscillatory shear measurements at a
fixed strain (γ= 1.0%) and variable dynamic frequency (ω) are
shown in Figure 2b. All of the above measurements were taken
at 80 °C. Interestingly, for all PAEPU-SPE@R15 samples, the
G′values are larger than the G″values in the low-strain, linear
viscoelastic regime, and the G′is independent of the frequency,
demonstrating that the materials possess solid-like elastic
consistency. In addition, it is found that the G′increases and
the dependence of G″on frequency decreases with the
increase of cross-linking density. Viscoelasticity is beneficial to
the uniform deposition of lithium dendrite and conducive to
the performance of the battery.
3.3. Morphology and Physicochemical Properties. As
shown in Figure 3, the surface morphology of the polymer
electrolyte was probed by SEM. Figure 3a−e shows the SEM
images of PAEPU-SPE@Rn(R = A, B, C, D, E; n= 15). It can
be noted that the microgel content of the surface of PAEPU-
SPE@Rndecreases with decrease of the tri-IPDI content at the
same content of lithium salt and with the increase of the
content of lithium salt at a fixed ratio of IPDI to tri-IPDI, and
there are few gel substances in PAEPU-SPE@D15 and PAEPU-
SPE@D25. This may be because the lithium salt plays a certain
“spacing role” in the polymerization process, which slows down
the reaction speed between −NH and −NCO. When the
content of lithium salt is too high, the contact probability of
the two groups is reduced, resulting in inadequate reaction and
surface wrinkling defects. Figure 3j,k, respectively, shows the
EDS characterization of the unique elements (S and F
element) in the lithium salt. The S and F elements are evenly
distributed, verifying the uniform dispersion of the lithium salt
in the SPE.
The transportation of lithium ions mainly relies on the
movement of the chain segments, which mainly occurs in the
amorphous area. The lithium-ion transmission can be more
intuitively understood through the XRD pattern. In order to
find out the reason for the improved Li+conduction, XRD was
carried out on the PAE membrane, PAEPU-SPE@R15 (R = A,
B, C, D, E), with dierent molar ratios of IPDI to tri-IPDI and
PAEPU-SPE@Dn(n= 0, 5, 15, 25) and dierent
concentrations of LiTFSI (Figure 4). It can be seen from
Figure 4. (a) XRD pattern of PAEPU-SPE@R15 (R = A, B, C, D, E). (b) XRD pattern of PAEPU-SPE@Dn(n= 0, 5, 15, 25).
Figure 5. DSC analysis of (a) PAEPU-SPE@R15 (R = A, B, C, D, E) and (b) PAEPU-SPE@Dn(n= 0, 5, 15, 25).
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20276
Figure 4 that the diraction peaks for the crystalline PEO chain
segments in PAE are located at 19.1 and 23.3°; nevertheless,
the diraction peaks of PAEPU-SPE@R15 and PAEPU-SPE@
Dnare widened and become diusion peaks due to the cross-
linking structure in PAEPU-based SPE, which restricts the
formation of crystallization, creating more amorphous regions
with the increase in molar ratio of tri-IPDI to IPDI or LiTFSI
content. Furthermore, there are no diraction peaks at 2θof
19.1 and 23.3°for PAEPU-SPE@R15 and PAEPU-SPE@Dn,
respectively; this may be because the intense diraction peaks
of PAEPU-based SPE mask the diraction peaks at 19.1 and
23.3°. The DSC experimental data confirmed that there are
melting points in PAEPU-based SPE except PAEPU-SPE@
D25.
The thermal transitions of the PAEPU-based SPE were
investigated by dierential scanning calorimetry (DSC). Figure
5a displays the heat flow as a function of temperature for
PAEPU-based SPEs with dierent molar ratios of the IPDI to
tri-IPDI ranging from 0:1 to 3:1 at 15 wt % of LiTFSI. It can
be seen that the melting temperatures (Tm) and glass transition
temperature (Tg) gradually reduced from PAEPU-SPE@B15 to
PAEPU-SPE@E15 with the increase in the molar ratios of IPDI
to tri-IPDI, indicating that the cross-linking disrupted the
crystallization tendency of PAEPU-based SPEs. Nevertheless,
PAEPU-SPE@A15 displayed the lowest Tgof −44.4 °C and Tm
of 25 °C. It may be that there was tri-IPDI only, resulting in
the viscosity increasing rapidly at the beginning of the reaction,
which hinders the movement of chain segments and
monomers to restrain the consequent reaction between PAE
and tri-IPDI to aect the mechanical strength of PAEPU-based
SPEs. Moreover, Figure 5b shows that the dosage of LiTFSI
aects the Tmand Tg. The decrease in Tmand the increase in
Tgindicate a transition from less to more interactions between
the ions in LiTFSI and PEO chain segments. Especially, at 25
wt % of LiTFSI, the crystallization peak disappeared
completely. This observation heralds a completely disrupt
crystallization of PEO chain segments. As a result, the chain
segment is more active, facilitating lithium-ion transfer and
achieving higher ionic conductivity. In addition, the PAEPU-
based SPEs exhibited outstanding thermal stability and the
thermal decomposition temperature of 5% weight loss was
above 300 °C, showing excellent stability under the condition
of thermal abuse displayed in Figure S1a,b.
3.4. Electrochemical Performance Characterization.
Ionic conductivity has been identified as the most important
means of characterizing the electrochemical properties of
polymer electrolytes. In this paper, the influences of dierent
LiTFSI content and dierent molar ratio of IPDI to tri-IPDI
on the ionic conductivity of the PAEPU-based SPE were
discussed. Figure 6 shows the curve of ionic conductivity
changing with temperature.
Figure 6. (a−c) Temperature dependence of the ionic conductivity of the PAEPU-based SPE, PAEPU-SPE@R5(R = A, B, C, D, E), PAEPU-
SPE@R15 (R = A, B, C, D, E), and PAEPU-SPE@R25 (R = A, B, C, D, E). (d) Linear fitting of ln σusing the Arrhenius model with T= 303.15K.
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20277
When the LiTFSI content is 5 or 15 wt %, the ionic
conductivity of the PAEPU-based SPE increased with the
decrease of tri-IPDI content. When the LiTFSI is 25 wt % and
the molar ratio of IPDI to tri-IPDI is 2:1, the ionic
conductivity of the PAEPU-based SPE reaches the highest
value, reaching 1.74 ×10−4S cm−1at 30 °C and 10−3S cm−1
above 70 °C.
As shown in Figure 6a−c, at the same LiTFSI content, the
ionic conductivity of the PAEPU-based SPE with an IPDI:tri-
IPDI mole ratio of 2:1 and 3:1 is higher than that of the
PAEPU-based SPE with the other three mole ratios of IPDI to
tri-IPDI. Although the ionic conductivity is the highest when
the LiTFSI is 25 wt %, the SPE is too soft and the morphology
is not as good as that of the PAEPU-based SPE with the
lithium content of 15 wt %. Considering all of the above
results, the properties of PAEPU-SPE@D15 were determined
by the following electrochemical tests.
The ionic conductivity of PAEPU-SPE@D15 is 6.80 ×10−5,
2.77 ×10−4, and 5.76 ×10−4S cm−1at 30, 60, and 80 °C,
respectively. The Arrhenius equation can be used to describe
the long-term transport mechanism of lithium ions in a
polymer matrix. The relationship between temperature and
conductivity is described by the following equation
Figure 7. (a) Electrochemical stability window at room temperature. (b) Chronoamperometry profile of the Li/PAEPU-SPE@D15/Li symmetric
battery. The inset shows the dependence spectra before and after chronoamperometry. (c) Nyquist plots of the interfacial resistance with time for
Li/PAEPU-based SPE@D15/Li.
Figure 8. Electrochemical performance of the Li/PAEPU-based SPE@D15/LiFePO4half-cell: (a) long cycle performance at 0.5C, 60 °C. (b)
Charge and discharge curves at 0.5C, 60 °C. (c) Rate performance at dierent current densities at 0.5C, 60 °C. (d) DC voltage measured by a
multimeter at room temperature. (e) Lighting up of a red LED lamp (1.9 V) by the assembled half-cell at room temperature.
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20278
=
i
k
j
j
jy
{
z
z
z
T A
E
KT
( ) exp a
where Arepresents the pre-factor, Earepresents the activation
energy, Krepresents the Boltzmann constant, and Trepresents
the thermodynamic temperature. According to the test results,
the linear fitting of PAEPU-SPE@D15 is displayed in Figure 6d
and the activation energy (Ea) of PAEPU-SPE@D15 is 0.40 eV.
Electrochemical stability window is an important perform-
ance index to measure the electrolyte stability. An Li//SS
asymmetric cell was assembled to evaluate the electrochemical
window, which was subsequently determined by linear sweep
voltammetry (LSV) at room temperature; the PAEPU-SPE@
D15 remains stable until 5.18 V (Figure 7a), demonstrating
good electrochemical stability, which makes it possible to
develop lithium batteries with high energy density.
The lithium-ion transference number (tLi+) was tested by EIS
test and DC polarization voltage was applied to the lithium
symmetric cell; the results are shown in Figure 7b. The
lithium-ion transference number of PAEPU-SPE@D15 is 0.28,
which is slightly higher than that of PEO-based polymer
electrolytes (tLi+= 0.20).
64
In this paper, the interface performance of the electrolyte/
lithium metal electrode was also studied in detail. By
monitoring the interface impedance of PAEPU-SPE@D15 at
ambient temperature, the change of impedance with time was
evaluated. As demonstrated in Figure 7c, the real part of the
high-frequency zone is the bulk impedance (Rb) of the
electrolyte, and the diameter of the arc is the interface
impedance (Ri) between the electrolyte and the electrode. As
time goes by, the passivation layer gradually forms and Rialso
slowly increases. Significantly, the interface impedance value
on the 15th day and the 20th day are almost the same,
indicating that a quite stable solid electrolyte interface (SEI)
has been formed. The formation of the SEI layer is conducive
to the uniform deposition of lithium dendrites, and also makes
the electrolyte and the electrode have good contact.
The half-cell was assembled with Li//LFP to further
evaluate the electrochemical performance and feasibility of
PAEPU-SPE@D15. As shown in Figure 8a,b, the cycle
performance was measured under the current density of
0.5C at 60 °C. Figure 8a shows that the Li/PAEPU-SPE@D15/
LiFePO4half-cell delivers an initial discharge capacity of 126.8
mAh g−1. After seven cycles of activation, a high specific
capacity 150.5 mAh g−1is still obtained, and then around this
value is maintained with a tremendous cycle stability. The
unstable charge−discharge specific capacity in the first few
cycles may be caused by the construction of the lithium-ion
transport channel.
65
After 100 cycles, the discharge capacity is
145.7 mAh g−1; compared with the discharge capacity of the
8th cycle, the capacity retention could reach 96.8%, and the
coulombic eciency always remained above 98.0%. Figure 8b
shows the galvanostatic charge−discharge voltage profiles
under the current density of 0.5C at 60 °C. Remarkably,
after five charge−discharge cycles, the voltage tends to be
stable, about 3.4 V, indicating that the Li/PAEPU-SPE@D15/
LFP had good stability. This is because the polyurea solid
polymer electrolyte has a three-dimensional network structure,
which is conducive to the stable performance of the battery.
Figure 8c shows the rate performance at dierent current
densities. The discharge capacities were 156.4, 152.7, 147.8,
137.5, and 97.6 mAh g−1at 0.1C, 0.2C, 0.5C, 1C, and 2C,
respectively. When the current density returned to 0.1C, the
reversible capacity remained at 153.1 mAh g−1, with a capacity
recovery rate of 97.9%, suggesting outstanding rate perform-
ance. However, the cyclic test results of the pure PEO solid
polymer electrolyte at 60 °C and current densities of 0.2C,
66
0.5C,
67,68
and 1C
68
were all lower than the specific capacity of
the PAEPU-SPE prepared in this experiment. Moreover, as
shown as Figure 8d,e, the DC voltage (3.39 V) was measured
by a multimeter, and it could light up a red LED lamp (1.9 V)
at room temperature successfully.
4. CONCLUSIONS
In summary, a series of PAEPU-based SPEs with abundant
PEO chains has been designed and successfully fabricated in an
in situ manner, which could achieve the integration of SPE
with the polar plate, while eliminating the use of solvents. We
systematically investigated the mechanics, thermal transition,
and transport behaviors of PAEPU-based SPEs by varying the
molar ratios of IPDI to tri-IPDI and LiTFSI concentrations
and identified trends in the viscoelasticity, thermal transition,
and ionic conductivity with polymer composition. The SPE
displays tunable mechanical properties and ionic conductivity,
excellent thermal stability (Td,5 > 300 °C), and a low glass
transition temperature (Tg<−40 °C). Additionally, at the
IPDI/tri-IPDI molar ratio of 2:1 and 15 wt % LiTFSI, an
optimum combination was observed in the PAEPU-based SPE
system, which was used to investigate the electrochemical
properties. Compared to PEO/LiTFSI, the PAEPU-based SPE
displayed a higher ionic conductivity of 6.80 ×10−5S cm−1at
30 °C and could reach 10−4orders of magnitude when the
temperature was above 40 °C, with a better electrochemical
stability window of 5.18 V and interface stability with lithium
metal. In addition, the capacity retention rate of the Li/
PAEPU-SPE@D15/LiFePO4half-cell was 96.8% after 100
cycles, and in the rate test, the capacity recovery rate could
reach 97.9%. The characteristics of a good interface
compatibility between the electrodes and electrolyte as well
as a reversible battery cycle make the solvent-free and in situ
PAEPU-based SPEs one of the most promising electrolytes for
next-generation all-solid-state batteries with flexible, wearable,
and highly improved safety as well as economic and
environmental benefits.
■ASSOCIATED CONTENT
*
sı Supporting Information
The Supporting Information is available free of charge at
https://pubs.acs.org/doi/10.1021/acsomega.2c07349.
Preparation of LiFePO4cathode and the image of
PAEPU-based SPE thermal performance (PDF)
■AUTHOR INFORMATION
Corresponding Authors
Peng Wang −Hebei Key Laboratory of Flexible Functional
Materials, School of Materials Science and Engineering, Hebei
University of Science and Technology, Shijiazhuang 050000,
China; orcid.org/0000-0001-9669-9343;
Email: wp390061130@126.com
Na Li −Hebei Key Laboratory of Flexible Functional
Materials, School of Materials Science and Engineering, Hebei
University of Science and Technology, Shijiazhuang 050000,
China; Email: linahuaxue@163.com
Jijun Xiao −Hebei Key Laboratory of Flexible Functional
Materials, School of Materials Science and Engineering, Hebei
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20279
University of Science and Technology, Shijiazhuang 050000,
China; Email: xiaojj@hebust.edu.cn
Authors
Lu Bai −Hebei Key Laboratory of Flexible Functional
Materials, School of Materials Science and Engineering, Hebei
University of Science and Technology, Shijiazhuang 050000,
China; Institute of Energy Source, Hebei Academy of Sciences,
Shijiazhuang 050052, China
Chengyu Li −Hebei Key Laboratory of Flexible Functional
Materials, School of Materials Science and Engineering, Hebei
University of Science and Technology, Shijiazhuang 050000,
China
Xiaoqi Chen −Institute of Energy Source, Hebei Academy of
Sciences, Shijiazhuang 050052, China
Yantao Li −Institute of Energy Source, Hebei Academy of
Sciences, Shijiazhuang 050052, China
Complete contact information is available at:
https://pubs.acs.org/10.1021/acsomega.2c07349
Author Contributions
§
L.B. and P.W. contributed equally to this work.
Notes
The authors declare no competing financial interest.
■ACKNOWLEDGMENTS
The authors gratefully acknowledge the financial support from
the National Natural Science Foundation of China (nos.
52174287, 5210011286, and 51904343), Science and Tech-
nology Program of Hunan Province (no. 2019RS3002), Funds
for Creative Research Groups of Hunan province (no.
2020JJ1007), the Hebei Provincial Natural Science Foundation
(E2021208031, B2021208069), and the Fundamental Re-
search Funds for the Hebei University (2021YWF11).
■REFERENCES
(1) Fan, E.; Li, L.; Wang, Z.; Lin, J.; Huang, Y.; Yao, Y.; Chen, R.;
Wu, F. Sustainable Recycling Technology for Li-ion Batteries and
Beyond: Challenges and Future Prospects. Chem. Rev. 2020,120,
7020−7063.
(2) Xia, S.; Wu, X.; Zhang, Z.; Cui, Y.; Liu, W. Practical Challenges
and Future Perspectives of All-Solid-State Lithium-Metal Batteries.
Chem 2019,5, 753−785.
(3) Wang, Q.; Cui, Z.; Zhou, Q.; Shangguan, X.; Du, X.; Dong, S.;
Qiao, L.; Huang, S.; Liu, X.; Tang, K.; et al. A Supramolecular
Interaction Strategy Enabling High-Performance All Solid State
Electrolyte of Lithium Metal Batteries. Energy Storage Mater. 2020,
25, 756−763.
(4) Wu, F.; Maier, J.; Yu, Y. Guidelines and Trends for Next-
Generation Rechargeable Lithium and Lithium-Ion Batteries. Chem.
Soc. Rev. 2020,49, 1569−1614.
(5) Yue, L.; Ma, J.; Zhang, J.; Zhao, J.; Dong, S.; Liu, Z.; Cui, G.;
Chen, L. All Solid-State Polymer Electrolytes for High-Performance
Lithium Ion Batteries. Energy Storage Mater. 2016,5, 139−164.
(6) Piedrahita, C.; Kusuma, V.; Nulwala, H. B.; Kyu, T. Highly
Conductive, Flexible Polymer Electrolyte Membrane Based on
Poly(ethylene glycol) Diacrylate-co-Thiosiloxane Network. Solid
State Ionics 2018,322, 61−68.
(7) Wang, Q.; Mao, B.; Stoliarov, S. I.; Sun, J. A Review of Lithium
Ion Battery Failure Mechanisms and Fire Prevention Strategies. Prog.
Energy Combust. Sci. 2019,73, 95−131.
(8) Feng, X.; Ouyang, M.; Liu, X.; Lu, L.; Xia, Y.; He, X. Thermal
Runaway Mechanism of Lithium Ion Battery for Electric Vehicles: A
Review. Energy Storage Mater. 2018,10, 246−267.
(9) Zhou, J.; Qian, T.; Liu, J.; Wang, M.; Zhang, L.; Yan, C. High
Safety All-Solid-State Lithium Metal Battery with High Ionic
Conductivity Thermoresponsive Solid Polymer Electrolyte. Nano
Lett. 2019,19, 3066−3073.
(10) Tianwei, Y.; Xiaofei, Y.; Rong, Y.; Xiangtao, B.; Guofeng, X.;
Shangqian, Z.; Yi, D.; Yanlong, W.; Jiantao, W. Progress and
Perspectives on Typical Inorganic Solid-State Electrolytes. J. Alloys
Compd. 2021,885, No. 161013.
(11) Karabelli, D.; Peter, B. K.; Max, W. A Performance and Cost
Overview of Selected Solid-State Electrolytes: Race between Polymer
Electrolytes and Inorganic Sulfide Electrolytes. Batteries 2021,7,
No. 18.
(12) Guan, X.; Min, X.; Shuanjin, W.; Dongmei, H.; Yuning, L.;
Yuezhong, M. Polymer-Based Solid Electrolytes: Material Selection,
Design, and Application. Adv. Funct. Mater. 2020,31, No. 2007598.
(13) Fengquan, L.; Fengjuan, B.; Jinxin, X.; Lu, W.; Yujie, Y.; Hong,
H.; Jianjun, Z.; Lin, L. Polymer Electrolyte Membrane with High
Ionic Conductivity and Enhanced Interfacial Stability for Lithium
Metal Battery. ACS Appl. Mater. Interfaces 2020,12, 22710−22720.
(14) Zeng, F.; Sun, Y.; Hui, B.; Xia, Y.; Zou, Y.; Zhang, X.; Yang, D.
Three-Dimensional Porous Alginate Fiber Membrane Reinforced
PEO-Based Solid Polymer Electrolyte for Safe and High-Performance
Lithium Ion Batteries. ACS Appl. Mater. Interfaces 2020,12, 43805−
43812.
(15) Zeng, D.; Yao, J.; Zhang, L.; Xu, R.; Wang, S.; Yan, X.; Yu, C.;
Wang, L. Promoting Favorable Interfacial Properties in Lithium-Based
Batteries Using Chlorine-Rich Sulfide Inorganic Solid-State Electro-
lytes. Nat. Commun. 2022,13, No. 1909.
(16) Wang, H.; Sheng, L.; Yasin, G.; Wang, L.; Xu, H.; He, X.
Reviewing the Current Status and Development of Polymer
Electrolytes for Solid-State Lithium Batteries. Energy Storage Mater.
2020,33, 188−215.
(17) Wang, Q.; Zhang, H.; Cui, Z.; Zhou, Q.; Shangguan, X.; Tian,
S.; Zhou, X.; Cui, G. Siloxane-Based Polymer Electrolytes for Solid-
State Lithium Batteries. Energy Storage Mater. 2019,23, 466−490.
(18) Fang, F.; Wei, L.; Yue, Z.; Kai, C.; Chen, S.; Lina, C.; Yulong,
L.; Haiming, X.; Liqun, S. Regulating Lithium Deposition via
Bifunctional Regular-Random Cross-Linking Network Solid Polymer
Electrolyte for Li Metal Batteries. J. Power Sources 2021,484,
No. 229186.
(19) Lopez, J.; Mackanic, D. G.; Cui, Y.; Bao, Z. Designing Polymers
for Advanced Battery Chemistries. Nat. Rev. Mater. 2019,4, 312−330.
(20) Xue, Z.; He, D.; Xie, X. Poly(ethylene oxide)-Based
Electrolytes for Lithium-Ion Batteries. J. Mater. Chem. A 2015,3,
19218−19253.
(21) Jeedi, V. R.; Narsaiah, E. L.; Yalla, M.; Swarnalatha, R.; Reddy,
S. N.; Sadananda Chary, A. Structural and Electrical Studies of
PMMA and PVDF Based Blend Polymer Electrolyte. SN Appl. Sci.
2020,2, 1−10.
(22) Tran, H. K.; Wu, Y.-S.; Chien, W.-C.; Wu, S.-h.; Jose, R.; Lue,
S. J.; Yang, C.-C. Composite Polymer Electrolytes Based on PVA/
PAN for All-Solid-State Lithium Metal Batteries Operated at Room
Temperature. ACS Appl. Energy Mater. 2020,3, 11024−11035.
(23) Kang, S.; Yang, C.; Yang, Z.; Wu, N.; Shi, B.; et al. Blending
Based PEO-PAN-PMMA Gel Polymer Electrolyte Prepared by
Spaying Casting for Solid-State Lithium Metal Batteries. Acta Chin.
Sin. 2020,78, No. 1441.
(24) Yao, Z.; Zhu, K.; Li, X.; Zhang, J.; Chen, J.; Wang, J.; Yan, K.;
Liu, J. 3D Poly(vinylidene fluoride-hexafluoropropylen) Nanofiber-
Reinforced PEO-Based Composite Polymer Electrolyte for High-
Voltage Lithium Metal Batteries. Electrochim. Acta 2021,404,
No. 139769.
(25) Olmedo-Martínez, J. L.; Porcarelli, L.; Guzmán-González, G.;
Calafel, I.; Forsyth, M.; Mecerreyes, D.; Muller, A. J. Ternary
Poly(ethylene oxide)/Poly(L, L-lactide) PEO/PLA Blends as High-
Temperature Solid Polymer Electrolytes for Lithium Batteries. ACS
Appl. Polym. Mater. 2021,3, 6326−6337.
(26) Aadheeshwaran, S.; Sankaranarayanan, K. Electrochemical
Behavior of BaTiO3Embedded Spongy PVDF-HFP/Cellulose
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20280
Blend as a Novel Gel Polymer Electrolyte for Lithium-Ion Batteries.
Mater. Lett. 2022,306, No. 130938.
(27) Bergfelt, A.; Rubatat, L.; Brandell, D.; Bowden, T. Poly(benzyl
methacrylate)-Poly[(oligo ethylene glycol) Methyl Ether Methacry-
late] Triblock-Copolymers as Solid Electrolyte for Lithium Batteries.
Solid State Ionics 2018,321, 55−61.
(28) Young, N. P.; Devaux, D.; Khurana, R.; Coates, G. W.; Balsara,
N. P. Investigating Polypropylene-Poly(ethylene oxide)-Polypropy-
lene Triblock Copolymers as Solid Polymer Electrolytes for Lithium
Batteries. Solid State Ionics 2014,263, 87−94.
(29) Zardalidis, G.; Gatsouli, K.; Pispas, S.; Mezger, M.; Floudas, G.
Ionic Conductivity, Self-Assembly, and Viscoelasticity in Poly-
(styrene-b-ethylene oxide) Electrolytes Doped with LiTf. Macro-
molecules 2015,48, 7164−7171.
(30) Butzelaar, A. J.; Roring, P.; Mach, T. P.; Hoffmann, M.;
Jeschull, F.; Wilhelm, M.; Winter, M.; Brunklaus, G.; Théato, P.
Styrene-Based Poly(ethylene oxide) Side-Chain Block Copolymers as
Solid Polymer Electrolytes for High-Voltage Lithium-Metal Batteries.
ACS Appl. Mater. Interfaces 2021,13, 39257−39270.
(31) Zhu, Y.; Cao, S.; Huo, F. Molecular Dynamics Simulation
Study of the Solid Polymer Electrolyte that PEO Grafted POSS.
Chem. Phys. Lett. 2020,756, No. 137834.
(32) Li, S.; Jiang, K.; Wang, J.; Zuo, C.; Xue, Z.; et al. Molecular
Brush with Dense PEG Side Chains: Design of a Well-Defined
Polymer Electrolyte for Lithium-Ion Batteries. Macromolecules 2019,
52, 7234−7243.
(33) Xu, S.; Sun, Z.; Sun, C.; Li, F.; Chen, K.; Zhang, Z.; Hou, G.;
Cheng, H. M.; Li, F. Homogeneous and Fast Ion Conduction of PEO-
Based Solid-State Electrolyte at Low Temperature. Adv. Funct. Mater.
2020,30, No. 2007172.
(34) Huang, Z.; Pan, Q.; Smith, D. M.; Li, C. Y. Plasticized Hybrid
Network Solid Polymer Electrolytes for Lithium-Metal Batteries. Adv.
Mater. Interfaces 2019,6, No. 1801445.
(35) Jinisha, B.; Anilkumar, K.; Manoj, M.; Pradeep, V.; Jayalekshmi,
S. Development of a Novel Type of solid Polymer Electrolyte for
Solid State Lithium Battery Applications Based on Lithium Enriched
Poly(ethylene oxide) (PEO)/Poly(vinyl pyrrolidone) (PVP) Blend
Polymer. Electrochim. Acta 2017,235, 210−222.
(36) Tao, C.; Gao, M. H.; Yin, B. H.; Li, B.; Huang, Y. P.; Xu, G.;
Bao, J. J. A Promising TPU/PEO Blend Polymer Electrolyte for All-
Solid-State Lithium Ion Batteries. Electrochim. Acta 2017,257, 31−39.
(37) Pan, X.; Yang, P.; Guo, Y.; Zhao, K.; Xi, B.; Lin, F.; Xiong, S.
Electrochemical and Nanomechanical Properties of TiO2Ceramic
Filler Li-Ion Composite Gel Polymer Electrolytes for Li Metal
Batteries. Adv. Mater. Interfaces 2021,8, No. 2100669.
(38) Mengistie, T. S.; Ko, J. M.; Kim, J. Y. Enhanced Single-Ion
Conduction and Free-Standing Properties of Solid Polymer Electro-
lyte by Incorporating a Polyelectrolyte. Mater. Res. Express 2021,8,
No. 035308.
(39) Ling, C. K.; Aung, M. M.; Rayung, M.; Abdullah, L. C.; Lim, H.
N.; Mohd Noor, I. S. Performance of Ionic Transport Properties in
Vegetable Oil-Based Polyurethane Acrylate Gel Polymer Electrolyte.
ACS Omega 2019,4, 2554−2564.
(40) Kalybekkyzy, S.; Kopzhassar, A.-F.; Kahraman, M. V.;
Mentbayeva, A.; Bakenov, Z. Fabrication of UV-Crosslinked Flexible
Solid Polymer Electrolyte with PDMS for Li-Ion Batteries. Polymers
2021,13, No. 15.
(41) Cai, M.; Zhu, J.; Yang, C.; Gao, R.; Shi, C.; Zhao, J. A Parallel
Bicomponent TPU/PI Membrane with mechanical Strength
Enhanced Isotropic Interfaces used as Polymer Electrolyte for
Lithium-Ion Battery. Polymers 2019,11, No. 185.
(42) Xu, P.; Chen, H.; Zhou, X.; Xiang, H. Gel Polymer Electrolyte
Based on PVDF-HFP Matrix Composited with rGO-PEG-NH2for
High-Performance Lithium Ion Battery. J. Membr. Sci. 2021,617,
No. 118660.
(43) Zaheer, M.; Xu, H.; Wang, B.; Li, L.; Deng, Y. An In Situ
Polymerized Comb-Like PLA/PEG-Based Solid Polymer Electrolyte
for Lithium Metal Batteries. J. Electrochem. Soc. 2019,167,
No. 070504.
(44) Mohamed, N.; Arof, A. Investigation of Electrical and
Electrochemical Properties of PVDF-Based Polymer Electrolytes. J.
Power Sources 2004,132, 229−234.
(45) Sun, J.; Li, Y.; Zhang, Q.; Hou, C.; Shi, Q.; Wang, H. A Highly
Ionic Conductive Poly(methyl methacrylate) Composite Electrolyte
with Garnet-Typed Li6.75La3Zr1.75Nb0.25O12 Nanowires. Chem. Eng. J.
2019,375, No. 121922.
(46) Wang, Z.; Shen, L.; Deng, S.; Cui, P.; Yao, X. 10 μm-Thick
High-Strength Solid Polymer Electrolytes with Excellent Interface
Compatibility for Flexible All-Solid-State Lithium-Metal Batteries.
Adv. Mater. 2021,33, No. 2100353.
(47) Liu, B.; Huang, Y.; Zhao, L.; Huang, Y.; Song, A.; Lin, Y.;
Wang, M.; Li, X.; Cao, H. A Novel Non-Woven Fabric Supported Gel
Polymer Electrolyte Based on Poly(methylmethacrylate-polyhedral
oligomeric silsesquioxane) by Phase Inversion Method for Lithium
Ion Batteries. J. Membr. Sci. 2018,564, 62−72.
(48) Zhao, Y.; Zhang, Y.; Bakenov, Z.; Chen, P. Electrochemical
Performance of Lithium Gel Polymer Battery with Nanostructured
Sulfur/Carbon Composite Cathode. Solid State Ionics 2013,234, 40−
45.
(49) Gan, H.; Li, S.; Zhang, Y.; Wang, J.; Xue, Z. Electrospun
Composite Polymer Electrolyte Membrane Enabled with Silica-
Coated Silver Nanowires. Eur. J. Inorg. Chem. 2021,2021, 4639−
4646.
(50) Janakiraman, S.; Surendran, A.; Ghosh, S.; Anandhan, S.;
Venimadhav, A. A New Strategy of PVDF Based Li-Salt Polymer
Electrolyte Through Electrospinning for Lithium Battery Application.
Mater. Res. Express 2019,6, No. 035303.
(51) Chai, J.; Liu, Z.; Ma, J.; Wang, J.; Liu, X.; Liu, H.; Zhang, J.;
Cui, G.; Chen, L. In Situ Generation of Poly(vinylene carbonate)
Based Solid Electrolyte with Interfacial Stability for LiCoO2Lithium
Batteries. Adv. Sci. 2017,4, No. 1600377.
(52) Wei, J.; Yue, H.; Shi, Z.; Li, Z.; Li, X.; Yin, Y.; Yang, S. In Situ
Gel Polymer Electrolyte with Inhibited Lithium Dendrite Growth and
Enhanced Interfacial Stability for Lithium-Metal Batteries. ACS Appl.
Mater. Interfaces 2021,13, 32486−32494.
(53) Sun, M.; Zeng, Z.; Peng, L.; Han, Z.; Yu, C.; Cheng, S.; Xie, J.
Ultrathin Polymer Electrolyte Film Prepared by In Situ Polymer-
ization for Lithium Metal Batteries. Mater. Today Energy 2021,21,
No. 100785.
(54) Choudhury, S.; Stalin, S.; Vu, D.; Warren, A.; Deng, Y.; Biswal,
P.; Archer, L. A. Solid-State Polymer Electrolytes for High-
Performance Lithium Metal Batteries. Nat. Commun. 2019,10,
No. 4398.
(55) Fu, F.; Lu, W.; Zheng, Y.; Chen, K.; Sun, C.; Cong, L.; Liu, Y.;
Xie, H.; Sun, L. Regulating Lithium Deposition via Bifunctional
Regular-Random Cross-Linking Network Solid Polymer Electrolyte
for Li Metal Batteries. J. Power Sources 2021,484, No. 229186.
(56) Liu, Z.; Guo, D.; Fan, W.; Xu, F.; Yao, X. Expansion-Tolerant
Lithium Anode with Built-In LiF-Rich Interface for Stable 400 Wh
kg‑1Lithium Metal Pouch Cells. ACS Mater. Lett. 2022,4, 1516−
1522.
(57) Liu, M.; Zhang, S.; Li, G.; Wang, C.; Li, B.; Li, M.; Wang, Y.;
Ming, H.; Wen, Y.; Qiu, J.; et al. A Cross-Linked Gel Polymer
Electrolyte Employing Cellulose Acetate Matrix and Layered Boron
Nitride Filler Prepared via In Situ Thermal Polymerization. J. Power
Sources 2021,484, No. 229235.
(58) Drews, M.; Trötschler, T.; Bauer, M.; Guntupalli, A.; Beichel,
W.; Gentischer, H.; Mulhaupt, R.; Kerscher, B.; Biro, D. Photocured
Cationic Polyoxazoline Macromonomers as Gel Polymer Electrolytes
for Lithium-Ion Batteries. ACS Appl. Polym. Mater. 2022,4, 158−168.
(59) Yu, F.; Zhang, H.; Zhao, L.; Sun, Z.; Li, Y.; Mo, Y.; Chen, Y. A
Flexible Cellulose/Methylcellulose Gel Polymer Electrolyte Endowing
Superior Li+Conducting Property for Lithium Ion Battery. Carbohydr.
Polym. 2020,246, No. 116622.
(60) Hess, H.; Kopp, R.; Groglerl, G.; Stepanski, H.; Hombach, R.;
Schafer, W. Polyurethane-Based Reactive Adhesives in Which the
Isocyanate is Stabilized by a Polyether Amine. U.S. Patent,
US5,104,959A1992.
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20281
(61) Pimenta, A. S.; Trianoski, R.; Pizzi, A.; Santiago-Medina, F. J.;
de Souza, E. C.; Monteiro, T. V. d. C.; Fasciotti, M.; Castro, R. V. O.
Effect of Polymeric Diisocyanate Addition on Bonding Performance
of a Demethylated-Pyrolysis-Oil-Based Adhesive. Wood Sci. Technol.
2019,53, 1311−1337.
(62) Xu, H.; Zhang, X.; Hu, G.; Weng, L.; Liu, L. High Thermal
Conductivity EP Adhesive Based on the GO/EP Interface Optimized
by TDI. Polym. Adv. Technol. 2020,31, 1356−1364.
(63) Jang, H. K.; Jung, B. M.; Choi, U. H.; Lee, S. B. Ion Conduction
and Viscoelastic Response of Epoxy-Based Solid Polymer Electrolytes
Containing Solvating Plastic Crystal Plasticizer. Macromol. Chem.
Phys. 2018,219, No. 1700514.
(64) Chen, B.; Huang, Z.; Chen, X.; Zhao, Y.; Xu, Q.; Long, P.;
Chen, S.; Xu, X. A New Composite Solid Electrolyte PEO/
Li10GeP2S12/SN for All-Solid-State Lithium Battery. Electrochim.
Acta 2016,210, 905−914.
(65) Zhang, D.; Xu, X.; Ji, S.; Wang, Z.; Liu, Z.; Shen, J.; Hu, R.; Liu,
J.; Zhu, M. Solvent-Free Method Prepared a Sandwich-Like
Nanofibrous Membrane-Reinforced Polymer Electrolyte for High-
Performance All-Solid-State Lithium Batteries. ACS Appl. Mater.
Interfaces 2020,12, 21586−21595.
(66) Tan, J.; Ao, X.; Dai, A.; Yuan, Y.; Zhuo, H.; Lu, H.; Zhuang, L.;
Ke, Y.; Su, C.; Peng, X.; et al. Polycation Ionic Liquid Tailored Peo-
Based Solid Polymer Electrolytes for High Temperature Lithium
Metal Batteries. Energy Storage Mater. 2020,33, 173−180.
(67) Zhu, L.; Zhu, P.; Fang, Q.; Jing, M.; Shen, X.; Yang, L. A Novel
Solid PEO/LLTO-Nanowires Polymer Composite Electrolyte for
Solid-State Lithium-Ion Battery. Electrochim. Acta 2018,292, 718−
726.
(68) Wen, J.; Zhao, Q.; Jiang, X.; Ji, G.; Wang, R.; Lu, G.; Long, J.;
Hu, N.; Xu, C. Graphene Oxide Enabled Flexible PEO-Based Solid
Polymer Electrolyte for All-Solid-State Lithium Metal Battery. ACS
Appl. Energy Mater. 2021,4, 3660−3669.
ACS Omega http://pubs.acs.org/journal/acsodf Article
https://doi.org/10.1021/acsomega.2c07349
ACS Omega 2023, 8, 20272−20282
20282
