Polymer Electrolytes For Lithium Batteries Research Articles

Misuse of XPS in Analyzing Solid Polymer Electrolytes for Lithium Batteries

One of the most powerful spectroscopic tools for battery analysis is X-ray photoelectron spectroscopy (XPS); however, its great power, must be accompanied by great responsibility for authenticity. Fluorine is documented to be unstable under XPS conditions, and fluorinated salts used in Li batteries show photodecomposition. As all-solid-state batteries advance, demand for surface characterization is increasing. Here, a popular solid polymer electrolyte comprising a fluorinated salt in a PEO matrix was measured by XPS. Rapid photodecomposition after few minutes produced mainly LiF, initially not found on the surface. Not being aware of such artifacts may lead to an erroneous analysis of the characterized electrochemical system.

Nanosecond solvation dynamics in a polymer electrolyte for lithium batteries.

Solvation dynamics critically affect charge transport. Spectroscopic experiments and computer simulations show that these dynamics in aqueous systems occur on a picosecond timescale. In the case of organic electrolytes, however, conflicting values ranging from 1 to several 100 picoseconds have been reported. We resolve this conflict by studying mixtures of an organic polymer and a lithium salt. Lithium ions coordinate with multiple polymer chains, resulting in temporary crosslinks. Relaxation of these crosslinks, detected by quasielastic neutron scattering, are directly related to solvation dynamics. Simulations reveal a broad spectrum of relaxation times. The average timescale for solvation dynamics in both experiment and simulation is one nanosecond. We present the direct measurement of ultraslow dynamics of solvation shell break-up in an electrolyte.

Solid-state polymer electrolytes in lithium batteries: latest progress and perspective

This review provides a comprehensive overview of solid-state polymer electrolytes performance characteristics of various chemical structures such as ethers, esters, nitrile and vinylidene fluoride.

Advancing Lithium Battery Performance through Gel Electrolytes: Investigating EC-Based Blends with HNBR and PEC for Enhanced Conductivity

Li-ion batteries (LiBs), the most established rechargeable energy storage devices, are currently at closing the gap of their theoretical capacity. That is the main reason why Lithium metal batteries (LMB) have recently regained interest, mainly because of the higher theoretical energy densities achievable with this technology. Therefore, the development of new electrode and electrolyte materials is essential for improving battery performance. Solid polymer electrolytes (SPEs) have been presented as safer alternatives for liquid electrolytes which are used commercially in these devices as they tend to be non-flammable, have enough mechanical strength to resist lithium dendrite growth, and do not leak. However, solid polymer electrolytes are less conductive than liquid electrolytes. Improved ionic conductivity in solid electrolyte materials can be obtained through the use of solid-state gel polymer electrolytes (GPEs). These materials combine the ionic conductivity of liquid electrolytes with the increased safety of SPE resulting in electrolytes with high ionic conductivity and good mechanical stability.1 This study introduces a novel approach to creating in-situ gel polymer electrolytes (GPEs) from solid polymer electrolytes (SPEs) using melt processing followed by sample heating. 2, 3This method capitalizes on the easy processability of SPEs. Initially, the SPE was prepared by blending two polymers with LiTFSI (bis(trifluoromethanesulfonyl)imide) through extrusion mixing. The sample was then converted into a GPE via a controlled heating step. Compared to the initial SPE, the resultant GPE possessed improved thermal and electrochemical properties. In this presentation, we will provide supportive data derived from IR, DSC, and NMR analyses to highlight the differences linked to changes in salt-polymer interactions in the GPE. Verdier, N.; Lepage, D.; Zidani, R.; Prebe, A.; Ayme-Perrot, D.; Pellerin, C.; Dolle, M.; Rochefort, D., Cross-linked polyacrylonitrile-based elastomer used as gel polymer electrolyte in Li-ion battery. ACS Applied Energy Materials 2019, 3 (1), 1099-1110.Ma, C.; Cui, W.; Liu, X.; Ding, Y.; Wang, Y., In situ preparation of gel polymer electrolyte for lithium batteries: Progress and perspectives. InfoMat 2021.Verdier, N.; Foran, G.; Lepage, D.; Prébé, A.; Aymé-Perrot, D.; Dollé, M., Challenges in Solvent-Free Methods for Manufacturing Electrodes and Electrolytes for Lithium-Based Batteries. Polymers 2021, 13 (3), 323.√

Transitioning Towards Asymmetric Gel Polymer Electrolytes for Lithium Batteries: Progress and Prospects

AbstractThe utilization of liquid electrolytes (LEs) concerns inevitable dendrite growth and safety issues. In contrast, solid polymer electrolytes suffer from unsettled low ionic conductivity and interfacial impedance issues. The intermediary gel polymer electrolytes (GPEs) improve safety by incorporating a sturdy polymer matrix and ionic conductivity as an advantage of percolating LEs responsible for gelation. The overall stability and compatibility of GPEs with different electrode materials depend on the polymers, plasticizers, and precursors utilized. No single polymer has a wide energy gap to exhibit stability against Li metal anodes and oxidative stability against high‐voltage cathodes. Thereafter, symmetric GPEs (SGPEs) possess limitations while simultaneously satisfying the two electrode requirements, which hinders their practical applications. Asymmetric GPEs (ASGPEs) generally comprise a bilayer or gradient structure, wherein the side contacting the cathode is modified to promote oxidative stability for a stable cathode electrolyte interface (CEI). The corresponding side in contact with the anode is modified to be mechanically and chemically compatible with dendritic lithium. Overall, asymmetric structural engineering enables electrode compatibility while maintaining the physical competency of GPEs. Herein, the focus is to summarize the current transition from SGPEs to asymmetric ones, which promotes multifunctionality while overcoming specific constraints associated with the electrodes.

Inorganic Composites Improving Conductivities of Solid Polymer Electrolytes for Lithium Batteries: A Review

AbstractFor high‐energy‐density lithium batteries, the research and development of solid‐state electrolytes is crucial. Inorganic‐organic composite electrolytes with high mechanical strength and ionic conductivity of inorganic ceramic electrolytes, as well as high interfacial compatibility of polymer electrolytes, have become a current research hotspot. Based on a brief discussion of lithium dendrite growth and Li+ ion transport mechanisms, this article provides a comprehensive review of the nanostructure design and performance of inorganic‐organic composite electrolytes in recent years, and focuses on the mechanism of homogeneous monolayer composite electrolytes and heterogeneous multilayer composite electrolytes to enhance the performance of electrolytes. In addition, the future prospect of inorganic‐organic composite electrolytes is discussed, providing practical guidance for researchers in this field.

Dicarbonate acrylate based single-ion conducting polymer electrolytes for lithium batteries

A series of carbonate-based single-ion conducting, solid polymer electrolytes were synthesized via reversible addition-fragmentation transfer copolymerization with anionic monomers. The abundant carbonate groups within the copolymers provide electron-delocalized complexation sites to aid Li+ dissociation from the polymer backbone, and the cyclic carbonates also provide a crosslinking site to improve mechanical properties. A single-ion conducting network polymer electrolyte prepared with dicarbonate acrylate (DCA) and trifluoromethane sulfonimide methacrylate (MTFSI) was UV-cured with a polyethylene oxide crosslinker and plasticized with vinylene carbonate (VC) to produce a high conductivity and high-performance electrolyte. The DCA-based polymer electrolyte had 0.16 mS/cm ionic conductivity at room temperature and transference number of 0.92. The use of VC was compared to a conventional electrolyte, ethylene carbonate and diethyl carbonate. The polymer electrolyte with VC showed excellent compatibility and stability with lithium. A lithium metal/lithium iron phosphate full cell with VC showed higher capacity and cycling stability than a cell with conventional plasticizers.

Facile Assembly of C–N Bond-Containing Polymer Electrolytes Enabled by Lithium Salt-Catalyzed Aza-Michael Addition

Assembling polymer electrolytes (PEs) with lithium metal anodes is a promising strategy to address safety and specific capacity concerns. Molecular design on conductive polymer matrices avoids inherent high crystallinity, poor ion transport, and combustion drawbacks by adjusting the chain structure and functional groups. However, conventional structural modulation methods are difficult to conduct via in situ polymerization and cell assembly, thus hampering the further performance enhancement of PEs in lithium batteries. Herein, we report a simple aza-Michael addition method induced by lithium salts for designing and fabricating high-performance PEs. This method fulfills the in situ structure modulation of polyether-based PEs without any introduction of non-electrolytic components. The obtained polyether electrolytes exhibit a more amorphous cross-linked structure, leading to a favorable medium for ion migration and excellent flexibility. In addition, the introduction of C–N bonds imparts excellent non-flammability to the material as well as the ability to interact with sulfolane. Hence, the in situ-constructed gel polymer electrolyte (GPE) is characterized by a high ionic conductivity (1.76 × 10–4 S cm–1 at 30 °C) and excellent interface stability with the electrodes. The assembled Li/LiFePO4 (LFP) battery based on this newly designed GPE exhibits a high initial specific discharge capacity and a good rate performance (112.7 mAh g–1 at 5 C). Long-term stability was also demonstrated, with a capacity retention of 86.8% after 500 cycles at 0.5 C.

Composition and Structure Design of Poly(vinylidene fluoride)‐Based Solid Polymer Electrolytes for Lithium Batteries

AbstractSolid‐state lithium batteries have become the focus of the next‐generation high‐safety lithium batteries due to their dimensional, thermal, and electrochemical stability. Thus, the progress of solid electrolytes with satisfactory comprehensive performances has become the key to promoting the development of solid batteries. Herein, poly(vinylidene fluoride) (PVDF) solid polymer electrolytes (SPEs) possess excellent flexibility, mechanical property, and high electrochemical and thermal stability, which show huge application potentiality in solid‐state lithium batteries and obtain extensive research. But the PVDF SPEs have been suffering from low ionic conductivity, high crystallinity, and low reactive sites. The development of PVDF‐based composite solid polymer electrolytes (CSPEs) has been confirmed to be a forceful strategy to optimize the performance of electrolytes. In this review, based on different design strategies, the recent progress of PVDF‐based SPEs is introduced in detail, especially in the mechanism of ionic conductivity enhancement and interface regulation by modified fillers. Besides, the applications of PVDF‐based SPEs in Li‐S and Li‐O2 battery systems are also introduced. Finally, this review presents some insights for promoting the development of high‐performance PVDF‐based SPEs.

Hollow multishelled structural ZnO fillers enhance the ionic conductivity of polymer electrolyte for lithium batteries

Hollow multishelled structural ZnO fillers enhance the ionic conductivity of polymer electrolyte for lithium batteries

High-Performance Poly(vinylidene fluoride)-Based Composite Polymer Electrolytes for Lithium Batteries Based on Halloysite Nanotubes with Polyethylene Oxide Additives

Solid polymer electrolytes (SPEs) are considered to be an important move to revive high-energy-density lithium-metal batteries due to their good flexibility and high safety. However, the low room-temperature ionic conductivity of SPEs has always been a stumbling block for their practical applications. Herein, a composite SPE has been fabricated by the cooperation of polyethylene oxide (PEO) and a type of natural nanoclay-halloysite nanotube (HNT) in a poly(vinylidene fluoride) (PVDF) matrix. It is expected that the sticky PEO can improve the interfacial stability of the SPE and lithium foil, while the special structure and surface charge properties of the HNTs changed the coordination environment of lithium ions and facilitated Li+ running on highways along the HNT outer surface. The optimized SPE composite showed an outstanding room-temperature ionic conductivity of 2.45 × 10–4 S cm–1 and high ion transference number of 0.67 at 25 °C. A LiFePO4/SPE-H5/Li full battery retained a discharge capacity of 142 mAh g–1 after 200 cycles at a rate of 0.2 C (25 °C). In addition, SPE-H5 can also be used in a 4.3 V high voltage NCM/SPE-H5/Li battery due to its excellent electrochemical stability window (more than 5 V). This work also reveals that lower-cost natural clay minerals are excellent nanoceramic fillers in realizing sustainable high-energy-density energy storage.

(Digital Presentation) Post-Treatment Study on Blended Polymer for Solid-State Lithium Batteries

The widely used Li batteries (LiBs) is the most established rechargeable energy storage device. Therefore, the development of new electrode and electrolyte materials is essential for improving battery performance. Solid polymer electrolytes (SPEs) have been presented as safer alternatives for liquid electrolytes as they tend to be non-flammable, have enough mechanical strength to resist dendrite growth, and do not leak. However, these materials tend to be less conductive than liquid electrolytes. This problem can be solved by solid-state gel polymer electrolytes (GPEs), which have lately received more attention. In fact, present a possible solution to this dilemma as they combine the ionic conductivity of liquid electrolytes with the increased safety of SPE to develop of electrolytes with high ionic conductivity and good mechanical stability.1 This work presents a preparation of in-situ GPE from SPE which produce by dry process in order to take advantage of the easy processability of SPE and the higher ionic conductivity of GPE.2, 3 The initial SPE was prepared by combining two polymers with LiTFSI (bis(trifluorormethanesulfonyl)imide) via extrusion mixing. This method of GPE processing was also found to improve other aspects of the electrolyte such as thermal and electrochemical properties which were characterized using cycling voltammetry, electrochemical impedance spectroscopy, and thermal gravimetric analysis. Additionally, the salt-polymer interaction in the GPE was characterized using FTIR, NMR, and the homogeneity of the polymer blend study by SEM-EDX. The cell of LFP/electrolyte/ Li metal showed a high capacity near to the theoretical one at C/20 at temperature 60 C. Additionally, the ionic conductivity of the electrolyte is around 10-5 S/cm. These first results confirmed that this blend of the polymers is a good electrolyte candidate for lithium batteries. Verdier, N.; Lepage, D.; Zidani, R.; Prebe, A.; Ayme-Perrot, D.; Pellerin, C.; Dolle, M.; Rochefort, D., Cross-linked polyacrylonitrile-based elastomer used as gel polymer electrolyte in Li-ion battery. ACS Applied Energy Materials 2019, 3 (1), 1099-1110.Ma, C.; Cui, W.; Liu, X.; Ding, Y.; Wang, Y., In situ preparation of gel polymer electrolyte for lithium batteries: Progress and perspectives. InfoMat 2021.Verdier, N.; Foran, G.; Lepage, D.; Prébé, A.; Aymé-Perrot, D.; Dollé, M., Challenges in Solvent-Free Methods for Manufacturing Electrodes and Electrolytes for Lithium-Based Batteries. Polymers 2021, 13 (3), 323.

Spiro-Twisted Benzoxazine Derivatives Bearing Nitrile Group for All-Solid-State Polymer Electrolytes in Lithium Batteries.

In this study, two nitrile-functionalized spiro-twisted benzoxazine monomers, namely 2,2′-((6,6,6′,6′-tetramethyl-6,6′,7,7′-tetrahydro-2H,2′H-8,8′-spirobi[indeno[5,6-e][1,3]oxazin]-3,3′(4H,4′H)-diyl)bis(4,1-phenylene))diacetonitrile (TSBZBC) and 4,4′-(6,6,6′,6′-tetramethyl-6,6′,7,7′-tetrahydro-2H,2′H-8,8′-spirobi[indeno[5,6-e][1,3]oxazin]-3,3′(4H,4′H)-diyl)dibenzonitrile (TSBZBN) were successfully developed as cross-linkable precursors. In addition, the incorporation of the nitrile group by covalent bonding onto the crosslinked spiro-twisted molecular chains improve the miscibility of SPE membranes with lithium salts while maintaining good mechanical properties. Owing to the presence of a high fractional free volume of spiro-twisted matrix, the –CN groups would have more space for rotation and vibration to assist lithium migration, especially for the benzyl cyanide-containing SPE. When combined with poly (ethylene oxide) (PEO) electrolytes, a new type of CN-containing semi-interpenetrating polymer networks for solid polymer electrolytes (SPEs) were prepared. The PEO-TSBZBC and PEO-TSBZBN composite SPEs (with 20 wt% crosslinked structure in the polymer) are denoted as the BC20 and BN20, respectively. The BC20 sample exhibited an ionic conductivity (σ) of 3.23 × 10−4 S cm−1 at 80 °C and a Li+ ion transference number of 0.187. The LiFePO4 (LFP)|BC20|Li sample exhibited a satisfactory charge–discharge capacity of 163.6 mAh g−1 at 0.1 C (with approximately 100% coulombic efficiency). Furthermore, the Li|BC20|Li cell was more stable during the Li plating/stripping process than the Li|BN20|Li and Li|PEO|Li samples. The Li|BC20|Li symmetric cell could be cycled continuously for more than 2700 h without short-circuiting. In addition, the specific capacity of the LFP|BC20|Li cell retained 87% of the original value after 50 cycles.

Bio-inspired design of electrospun poly(acrylonitrile) and novel ionene based nanofibrous mats as highly flexible solid state polymer electrolyte for lithium batteries

All-solid-state polymer electrolytes (ASSPEs) have significant importance in the development of rechargeable lithium batteries with superior safety. Herein, a unique ionene oligomer is synthesized from 1,4-Diazabicyclo [2.2.2] octane (DABCO) and diethylene glycol bis(2-chloroethyl)ether having bis(trifluoromethanesulfonyl) imide (TFSI−) as the anion (PO3TFSI, where, ‘P’ indicates the oligomer and ‘O3′ denotes the 3 oxyethylene units). The ASSPE was fabricated by a straightforward viable procedure involving uniaxial electrospinning of poly(acrylonitrile) (PAN) blended with PO3TFSI and doped with lithium bis (trifluoromethanesulfonyl)imide salt (LiTFSI). The prepared electrospun (PAN/PO3TFSI/LiTFSI) ASSPE presented an intriguing morphology following heat-treatment like the venation found on a leaf blade where the network of veins is responsible for providing support to the entire lamina. The final structure consists of a PAN framework with the ionene oligomer flowing out of and around the fibers, closing the pores of the nanofibrous mat in the process. The ASSPE having such leaf blade inspired veined morphology with closed pores exhibits a high room-temperature ionic conductivity of 1.01 × 10−3 S cm−1, an electrochemical stability window of ∼ 4.6 V, and outstanding thermal stability. The solid-state Li/LiFePO4 (LFP) batteries assembled with the (PAN/PO3TFSI/LiTFSI) ASSPE showed good Coulombic efficiency above 98% when cycled at 0.2C for 100 cycles at both 25 °C and 60 °C. Furthermore, the ASSPE showed potential application in all-solid-state lithium sulfur battery. Additionally, a flexible Li/ASSPE/LFP custom made cell was demonstrated to work even in extremely deformed conditions, such as being folded, crimped and rolled, indicating the high flexibility of the fiber based solid electrolyte.

Designing Boron‐Based Single‐Ion Gel Polymer Electrolytes for Lithium Batteries by Photopolymerization

AbstractSingle‐ion lithium conducting polymer electrolytes based on delocalized borate groups are designed and synthesized by rapid UV‐photopolymerization. For this purpose, three different functional lithium boron sp3 anionic monomers, containing fluorinated, ethoxy, or a blend of both functionalities are synthesized. These monomers are photopolymerized in the presence of a poly(ethylene glycol) dimethacrylate crosslinker and tetraglyme as plasticizer. By this method, gel polymer electrolytes endowed with lithium single‐ion conduction are prepared (SIGPEs). The impact generated by the different functionalities of the borate groups and the addition of plasticizer on the electrochemical and ion conducting properties of the synthesized polymer electrolytes are analyzed in detail. These polymer electrolytes show high ionic conductivity (1.71 × 10−4 S cm−1 at 25 °C) and high lithium transference number values (up to 0.85). Finally, they are investigated as solid electrolytes in lithium metal symmetrical cells showing good performance (<0.85 V at ±0.2 mA cm−2 for 175 h).

Functional Applications of Polymer Electrolytes in High‐Energy‐Density Lithium Batteries

AbstractPolymer electrolytes have attracted great interest in advanced lithium batteries. Recently, it has been found that there are many functional applications of polymer electrolytes in lithium batteries, which are very important for the development of high‐energy‐density lithium batteries. In this review, the functional applications of polymer electrolytes are reviewed in terms of protecting lithium metal anode, coating for high‐voltage cathodes, and improving the safety of batteries. Finally, the remaining challenges and future perspectives of polymer electrolytes in these functional applications are presented. This review aims to provide a comprehensive understanding of polymer electrolytes and promotes their functional application in high‐energy‐density lithium batteries.

Plasticized and salt-doped single-ion conducting polymer electrolytes for lithium batteries.

Single-ion conducting polymer electrolytes created by plasticizing LiPSTFSI with PPO and LiTFSI are shown to both improve the ionic conductivity and alter the ion conduction mechanism. This correlates with both local and macroscopic properties, opening for rational design of solid-state, but yet pliable electrolytes.

Ternary Poly(ethylene oxide)/Poly(l,l-lactide) PEO/PLA Blends as High-Temperature Solid Polymer Electrolytes for Lithium Batteries

Lithium batteries are in high demand in different technological fields. However, the operating temperature is required to be below 70 °C, and this limits their use in applications demanding high-energy rechargeable batteries that are able to operate at temperatures above 100 °C. Poly(ethylene oxide) (PEO) is, currently, the reference solid polymer electrolyte (SPE) employed in solid-state lithium batteries. However, the application of PEO at higher temperatures is restricted due to the loss of mechanical properties. In this article, we show that the polymer blending strategy of blending PEO with poly(l,l-lactide) (PLA) allows extending its use in batteries at high temperatures (100 °C). This improvement is due to the mechanical reinforcement of PEO solid electrolytes associated with the presence of PLA crystals. Thus, two solid electrolyte systems based on PEO/PLA blends with either a LiTFSI salt or a lithium single-ion polymer (poly(lithium-1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethanesulfonyl)imide), PLiMTFSI) were investigated and compared. Differential scanning calorimetry (DSC) results indicate that regardless of the concentration of LiTFSI or PLiMTFSI in the blend, crystals of PLA are present with melting peaks at 160–170 °C and the lithium salt distributes preferentially in the PEO-rich amorphous phases. The ionic conductivity is negatively affected by the incorporation of PLA in the blends. However, at high temperatures (>70 °C), ionic conductivities of ∼10–4 S cm–1 were obtained for both systems. DMTA results showed that PLA addition increases the mechanical properties of the electrolytes, yielding storage modulus values of ∼106 Pa for the PEO/PLA/LiTFSI blend and ∼107 Pa or higher for the PEO/PLA/PLiMTFSI blend at high temperatures (100 °C). Finally, both ternary blends were compared in a symmetrical lithium battery at 100 °C, and the single-ion conducting PEO/PLA/PLiMTFSI system presented lower overpotentials, which is reflected in a lower polarization inside the lithium battery.

Polyurethane-based polymer electrolytes for lithium Batteries: Advances and perspectives

Polymer electrolytes (PEs) have been widely regarded as an effective approach to eliminate most of the potential safety hazards encountered in traditional liquid electrolytes for lithium batteries (LBs). Substantial research efforts have been devoted to exploiting excellent performance PE systems, including poly(ethylene oxide) (PEO), polyurethane (PU), polysiloxane (PS), polyvinylidene fluoride (PVDF) and polycarbonate (PC)-based PEs. Among them, PU-based PEs have attracted increasing interests due to their flexibility of structure manipulation, excellent mechanical strength, facile modification, high thermal and electrochemical stability. However, to date, separated and detailed reviews on the progress of PU-based PEs are rarely reported. In this review, we comprehensively summarize the key progress on PU-based PEs from the perspective of flexible structure design strategies, basic electrochemical/mechanical properties, typical modification methods, specific functions, and their potential applications in LBs. Furthermore, synthesis routes of PUs and perspectives of PU-based PEs are also discussed. It is believed that this review will be of great guiding significance for exploiting high performance PU-based PEs for next-generation LBs.

In situ preparation of gel polymer electrolyte for lithium batteries: Progress and perspectives

AbstractThe practical applications of Li‐ion batteries (LIBs) are challenged by their safety concerns when using liquid electrolytes (LEs). Solid‐state gel polymer electrolytes (GPEs) can address this challenge and have drawn increased attention recently. Normally, GPEs are prepared separately and then assembled into cells, which undoubtedly result in dissatisfactory solid/solid interfacial compatibility and low ionic conductivity. Fortunately, in situ GPEs are proposed to address the above challenges and simplify the preparation process. Typically, LE precursor is injected into the cells and gradually transformed into a quasi‐solid gel state under the conditions of thermal or chemical initiators. Consequently, the obtained in situ GPEs could fully infiltrate the electrode and better interface contact of gel electrolyte/electrode is thus inherited. In this review, the authors focus on the in situ GPEs used in lithium batteries (LBs), and summarize recent progress of the design, synthesis, and applications of in situ GPEs. Based on the different ways of triggering polymerization, there are mainly three methods: thermochemical gelation, polymerization by additional chemical initiators, and cross‐linking initiated by LiO bond. Composite GPEs based on in situ solidification method are introduced as a promising strategy to improve the electrochemical performances. Finally, up‐to‐date research progresses are discussed, and perspectives are provided on the development and challenges of in situ GPEs to meet the requirements for their practical applications in LBs.image