A Sodium‐Ion Battery with a Low‐Cost Cross‐Linked Gel‐Polymer Electrolyte

The design of a sodium‐ion rechargeable battery with an antimony anode, a Na₃V₂(PO₄)₃ cathode, and a low‐cost composite gel‐polymer electrolyte based on cross‐linked poly(methyl methacrylate) is reported. The application of an antimony anode, on replacement of the sodium metal that is commonly used in sodium‐ion half‐cells, reduces significantly the interfacial resistance and charge transfer resistance of a sodium‐ion battery, which enables a smaller polarization for a sodium‐ion full‐cell Sb/Na₃V₂(PO₄)₃ running at relatively high charge and discharge rates. The incorporation of the gel‐polymer electrolyte is beneficial to maintain stable interfaces between the electrolyte and the electrodes of the sodium‐ion battery at elevated temperature. When running at 60 °C, the sodium‐ion full‐cell Sb/Na₃V₂(PO₄)₃ with the gel‐polymer electrolyte exhibits superior cycling stability compared to a battery with the conventional liquid electrolyte.     

In Situ Generated Fireproof Gel Polymer Electrolyte with Li6.4Ga0.2La3Zr2O12 As Initiator and Ion‐Conductive Filler

Poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) based gel polymer electrolyte is regarded as a promising candidate to settle the safety issues of liquid electrolytes. However, the currently reported gel polymer electrolytes are still not safe enough owing to high amount of flammable liquid solvents contained in them. Herein, a fireproof PVDF‐HFP based gel polymer electrolyte is designed and synthesized through an in situ crosslinking method, with Li_6.4Ga_0.2La₃Zr₂O₁₂ as initiator and ion‐conductive filler. The obtained gel polymer electrolyte demonstrates superior fire resisting properties. The optimized gel polymer electrolyte exhibits an ionic conductivity as high as 1.84 × 10^?3 S cm^?1 at 20 °C with an electrochemical window up to 4.75 V at room temperature. Moreover, the obtained gel polymer electrolyte shows excellent compatibility with lithium anodes. Therefore, the lithium anode is well protected. Lithium batteries assembled with the gel polymer electrolyte possess superb safety properties in cutting and burning tests. Furthermore, the batteries also show a discharge retention rate as high as 94.08% (in comparison with the initial discharge capacity) after cycling at 0.5 C for 360 cycles with an average columbic efficiency higher than 98%. The purpose of this report is to show the great potential of applying fire‐retardant gel polymer electrolyte to achieve high safety lithium batteries.     

Triple‐Layer Structured Composite Separator Membranes with Dual Pore Structures and Improved Interfacial Contact for Sustainable Dye‐Sensitized Solar Cells

A composite separator membrane (CSM) with an A/B/A type layered structure, composed of a microporous electrolyte‐philic poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVdF‐HFP) gel layer (A) and a submicrometer porous polyethylene (PE) or a macroporous poly(ethylene terephthalate) (PET) non‐woven matrix (B), is introduced in a dye‐sensitized solar cell (DSSC). Commercially available PE and PET separator membranes (SMs) act as matrices that provide mechanical stability to the DSSC and permanent pore structures for facilitated ion transport. PVdF‐HFP is used as a microporous gelator for improved interfacial contact between the solid SM and the electrodes. The PVdF‐HFP gel impedes the charge recombination process between electron and I₃ ^? at the TiO₂/electrolyte interface, resulting in improved electron lifetimes. The DSSC assembled with the CSM exhibits high initial solar energy conversion efficiency (η, 6.1%) and stable η values over 1400 h, demonstrating good long term stability. The behaviors of the DSSC are attributed to the synergistic factors of the CSM, such as improved ion conductivity, electrolyte affinity, electrolyte retention capability, effective interfacial contact, and plausible passivation of the dyes. This study demonstrates a practical combination of short‐ and long‐term DSSC performance through the introduction of the CSM.     

Single‐Ion Conducting Electrolyte Based on Electrospun Nanofibers for High‐Performance Lithium Batteries

Herein, a novel electrospun single‐ion conducting polymer electrolyte (SIPE) composed of nanoscale mixed poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) and lithium poly(4,4′‐diaminodiphenylsulfone, bis(4‐carbonyl benzene sulfonyl)imide) (LiPSI) is reported, which simultaneously overcomes the drawbacks of the polyolefin‐based separator (low porosity and poor electrolyte wettability and thermal dimensional stability) and the LiPF₆ salt (poor thermal stability and moisture sensitivity). The electrospun nanofiber membrane (es‐PVPSI) has high porosity and appropriate mechanical strength. The fully aromatic polyamide backbone enables high thermal dimensional stability of es‐PVPSI membrane even at 300 °C, while the high polarity and high porosity ensures fast electrolyte wetting. Impregnation of the membrane with the ethylene carbonate (EC)/dimethyl carbonate (DMC) (v:v = 1:1) solvent mixture yields a SIPE offering wide electrochemical stability, good ionic conductivity, and high lithium‐ion transference number. Based on the above‐mentioned merits, Li/LiFePO₄ cells using such a SIPE exhibit excellent rate capacity and outstanding electrochemical stability for 1000 cycles at least, indicating that such an electrolyte can replace the conventional liquid electrolyte–polyolefin combination in lithium ion batteries (LIBs). In addition, the long‐term stripping–plating cycling test coupled with scanning electron microscope (SEM) images of lithium foil clearly confirms that the es‐PVPSI membrane is capable of suppressing lithium dendrite growth, which is fundamental for its use in high‐energy Li metal batteries.     

Facilitating Interfacial Stability Via Bilayer Heterostructure Solid Electrolyte Toward High‐energy,Safe and Adaptable Lithium Batteries

Solid‐state electrolytes are widely anticipated to enable the revival of high energy density and safe metallic Li batteries, however, their lower ionic conductivity at room temperature, stiff interfacial contact, and severe polarization during cycling continue to pose challenges in practical applications. Herein, a dual‐composite concept is applied to the design of a bilayer heterostructure solid electrolyte composed of Li⁺ conductive garnet nanowires (Li_6.75La₃Zr_1.75Nb_0.25O₁₂)/polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF‐HFP) as a tough matrix and modified metal organic framework particles/polyethylene oxide/PVDF‐HFP as an interfacial gel. The integral ionic conductivity of the solid electrolyte reaches 2.0 × 10^?4 S cm^?1 at room temperature. In addition, a chemically/electrochemically stable interface is rapidly formed, and Li dendrites are well restrained by a robust inorganic shield and matrix. As a result, steady Li plating/stripping for more than 1700 h at 0.25 mA cm^?2 is achieved. Solid‐state batteries using this bilayer heterostructure solid electrolyte deliver promising battery performance (efficient capacity output and cycling stability) at ambient temperature (25 °C). Moreover, the pouch cells exhibit considerable flexibility in service and unexpected endurance under a series of extreme abuse tests including hitting with a nail, burning, immersion under water, and freezing in liquid nitrogen.     

A Composite Gel Polymer Electrolyte with High Performance Based on Poly(Vinylidene Fluoride) and Polyborate for Lithium Ion Batteries

A composite membrane based on electrospun poly(vinylidene fluoride) (PVDF) and lithium polyvinyl alcohol oxalate borate (LiPVAOB) exhibiting high safety (self‐extinguishing) and good mechanical property is prepared. The ionic conductivity of the as‐prepared gel polymer electrolyte from this composite membrane saturated with 1 mol L^?1 LiPF₆ electrolyte at ambient temperature can be up to 0.26 mS cm^?1, higher than that of the corresponding well‐used commercial separator (Celgard 2730), 0.21 mS cm^?1. Moreover, the lithium ion transference in the gel polymer electrolyte at room temperature is 0.58, twice as that in the commercial separator (0.27). Furthermore, the absorbed electrolyte solvent is difficult to evaporate at elevated temperature. Its electrochemical performance is evaluated by using LiFePO₄ cathode. The obtained results suggest that this gel‐type composite membrane shows great possibilities for use in large‐capacity lithium ion batteries that require high safety.     

All‐Solid‐State Fiber Supercapacitors with Ultrahigh Volumetric Energy Density and Outstanding Flexibility

Fiber supercapacitors (FSCs) represent a promising class of energy storage devices that can complement or even replace microbatteries in miniaturized portable and wearable electronics. One of their main limitations, however, is the low volumetric energy density when compared with those of rechargeable batteries. Considering the energy density of FSC is proportional to CV² (E = 1/2 CV², where C is the capacitance and V is the operating voltage), one would explore high operating voltage as an effective strategy to promote the volumetric energy density. In the present work, an all‐solid‐state asymmetric FSC (AFSC) with a maximum operating voltage of 3.5 V is successfully achieved, by employing an ionic liquid (IL) incorporated gel‐polymer as the electrolyte (EMIMTFSI/PVDF‐HFP). The optimized AFSC is based on MnO_x@TiN nanowires@carbon nanotube (NWs@CNT) fiber as the positive electrode and C@TiN NWs@CNT fiber as the negative electrode, which gives rise to an ultrahigh stack volumetric energy density of 61.2 mW h cm^?3, being even comparable to those of commercially planar lead‐acid batteries (50–90 mW h cm^?3), and an excellent flexibility of 92.7% retention after 1000 blending cycles at 90°. The demonstration of employing the ILs‐based electrolyte opens up new opportunities to fabricate high‐performance flexible AFSC for future portable and wearable electronic devices.     

Highly‐Safe and Ultra‐Stable All‐Flexible Gel Polymer Lithium Ion Batteries Aiming for Scalable Applications

With the development of flexible electronics, flexible lithium ion batteries (LIBs) have received great attention. Previously, almost all reported flexible components had shortcomings related to poor mechanical flexibility, low energy density, and poor safety, which led to the failure of scalable applications. This study demonstrates a fully flexible lithium ion battery using LiCoO₂ as the cathode, Li₄Ti₅O₁₂ as the anode, and graphene film as the flexible current collector. The graphene oxide modified gel polymer electrolyte exhibits higher ionic conductivity than a conventional liquid electrolyte and improves the safety of the flexible battery. The optimum design of the flexible graphene battery exhibits super electrochemical performance, with a 2.3 V output voltage plateau and a satisfactory capacity of 143.0 mAh g^?1 at 1 C. The mass energy density and power density are both ≈1.4 times higher than a standard electrode using metal foils as current collectors. No capacity loss is observed after 100 thousand cycles of mechanical bending. More importantly, even in the clipping state, this flexible gel polymer battery can still demonstrate a stable and safe electrochemical performance. This work may lead to a promising strategy of high‐performance scalable LIBs for the next‐generation flexible electronics.     

A Flexible Solid Electrolyte with Multilayer Structure for Sodium Metal Batteries

Solid electrolytes (SEs) can potentially address the inherent safety problems of conventional organic liquid electrolytes. However, their low ionic conductivity and large interfacial resistance limit the practical applications of SEs. Here, a flexible solid electrolyte with a multilayer structure is fabricated by the UV curing of an interpenetrating network of poly(ether‐acrylate) (ipn‐PEA) in the Na₃Zr₂Si₂PO₁₂/poly(vinylidene fluoride‐hexafluoropropylene) porous skeleton (NZSP/PVDF‐HFP), exhibiting a high Na⁺ transference number of 0.63 and a suitable ionic conductivity of above 10^?4 S cm^?1 at 60 °C. In addition, due to the unique structure of the internal rigidity and external flexibility, the composite solid electrolyte can effectively mitigate interfacial ion transfer issues while guaranteeing a certain mechanical strength, and largely inhibiting the formation of dendrite and dead sodium. The solid sodium metal batteries using Na₃V₂(PO₄)₃ (NVP) as a cathode possess a discharge capacity of 85 mA h g^?1 after 100 cycles at 0.5 C, and achieve above 90% of capacity retention rate during 100 cycles at 0.1 C for Na_2/3Ni_1/3Mn_1/3Ti_1/3O₂ (NTMO) at 60 °C. The flexible solid electrolyte with multilayer structure shows a great advantage for managing the ionic conductivity and interface resistance problem, suggesting a promise as a practical sodium metal battery.     

Fluorine‐Free Noble Salt Anion for High‐Performance All‐Solid‐State Lithium–Sulfur Batteries

Amongst post‐Li‐ion battery technologies, lithium–sulfur (Li–S) batteries have captured an immense interest as one of the most appealing devices from both the industrial and academia sectors. The replacement of conventional liquid electrolytes with solid polymer electrolytes (SPEs) enables not only a safer use of Li metal (Li°) anodes but also a flexible design in the shape of Li–S batteries. However, the practical implementation of SPEs‐based all‐solid‐state Li–S batteries (ASSLSBs) is largely hindered by the shuttling effect of the polysulfide intermediates and the formation of dendritic Li° during the battery operation. Herein, a fluorine‐free noble salt anion, tricyanomethanide [C(CN)₃^?, TCM^?], is proposed as a Li‐ion conducting salt for ASSLSBs. Compared to the widely used perfluorinated anions {e.g., bis(trifluoromethanesulfonyl)imide anion, [N(SO₂CF₃)₂)]^?, TFSI^?}, the LiTCM‐based electrolytes show decent ionic conductivity, good thermal stability, and sufficient anodic stability suiting the cell chemistry of ASSLSBs. In particular, the fluorine‐free solid electrolyte interphase layer originating from the decomposition of LiTCM exhibits a good mechanical integrity and Li‐ion conductivity, which allows the LiTCM‐based Li–S cells to be cycled with good rate capability and Coulombic efficiency. The LiTCM‐based electrolytes are believed to be the most promising candidates for building cost‐effective and high energy density ASSLSBs in the near future.     

Stable Seamless Interfaces and Rapid Ionic Conductivity of Ca–CeO2/LiTFSI/PEO Composite Electrolyte for High‐Rate and High‐Voltage All‐Solid‐State Battery

Stable and seamless interfaces among solid components in all‐solid‐state batteries (ASSBs) are crucial for high ionic conductivity and high rate performance. This can be achieved by the combination of functional inorganic material and flexible polymer solid electrolyte. In this work, a flexible all‐solid‐state composite electrolyte is synthesized based on oxygen‐vacancy‐rich Ca‐doped CeO₂ (Ca–CeO₂) nanotube, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and poly(ethylene oxide) (PEO), namely Ca–CeO₂/LiTFSI/PEO. Ca–CeO₂ nanotubes play a key role in enhancing the ionic conductivity and mechanical strength while the PEO offers flexibility and assures the stable seamless contact between the solid electrolyte and the electrodes in ASSBs. The as‐prepared electrolyte exhibits high ionic conductivity of 1.3 × 10^?4 S cm^?1 at 60 °C, a high lithium ion transference number of 0.453, and high‐voltage stability. More importantly, various electrochemical characterizations and density functional theory (DFT) calculations reveal that Ca–CeO₂ helps dissociate LiTFSI, produce free Li ions, and therefore enhance ionic conductivity. The ASSBs based on the as‐prepared Ca–CeO₂/LiTFSI/PEO composite electrolyte deliver high‐rate capability and high‐voltage stability.     

Formation of Solid–Electrolyte Interfaces in Aqueous Electrolytes by Altering Cation‐Solvation Shell Structure

Aqueous lithium/sodium‐ion batteries (AIBs) have received increasing attention because of their intrinsic safety. However, the narrow electrochemical stability window (1.23 V) of the aqueous electrolyte significantly hinders the development of AIBs, especially the choice of electrode materials. Here, an aqueous electrolyte composed of LiClO₄, urea, and H₂O, which allows the electrochemical stability window to be expanded to 3.0 V, is developed. Novel [Li (H₂O)_x(organic)_y]⁺ primary solvation sheath structures are developed in this aqueous electrolyte, which contribute to the formation of solid–electrolyte interface layers on the surfaces of both the cathode and anode. The expanded electrochemical stability window enables the construction of full aqueous Li‐ion batteries with LiMn₂O₄ cathodes and Mo₆S₈ anodes, demonstrating an operating voltage of 2.1 V and stability over 2000 cycles. Furthermore, a symmetric aqueous Na‐ion battery using Na₃V₂(PO₄)₃ as both the cathode and anode exhibits operating voltage of 1.7 V and stability over 1000 cycles at a rate of 5 C.     

High Performance Na–CuCl2 Rechargeable Battery toward Room Temperature ZEBRA‐Type Battery

Despite a recent increase in the attention given to sodium rechargeable battery systems, they should be further advanced in terms of their energy density and reliability to successfully penetrate the rechargeable battery market. Here, a new room temperature ZEBRA‐type Na–CuCl₂ rechargeable battery is demonstrated that employs CuCl₂ cathode material and nonflammable inorganic liquid electrolyte. The cathode delivers a high energy density of ≈580 Wh kg^?1 with superior capacity retention over 1000 cycles as well as a high round‐trip efficiency of ≈97%, which has never been obtained in an organic electrolyte system and high‐temperature ZEBRA‐type battery. These excellent electrochemical performances are mainly attributed to the use of the SO₂‐based inorganic electrolyte, which guarantees a reversible conversion reaction between CuCl₂ and CuCl with NaCl. It is also demonstrated that the proposed battery chemistry can be extended to other copper halide materials including CuBr₂ and CuF₂, which also show highly promising battery performances as cathode materials for the Na–Cu halide battery system.     

Aqueous Electrochemical Energy Storage with a Mediator‐Ion Solid Electrolyte

This study presents a battery concept with a “mediator‐ion” solid electrolyte for the development of next‐generation electrochemical energy storage technologies. The active anode and cathode materials in a single cell can be in the solid, liquid, or gaseous form, which are separated by a sodium‐ion solid‐electrolyte separator. The uniqueness of this mediator‐ion strategy is that the redox reactions at the anode and the cathode are sustained by a shuttling of a mediator sodium ion between the anolyte and the catholyte through the solid‐state electrolyte. Use of the solid‐electrolyte separator circumvents the chemical‐crossover problem between the anode and the cathode, overcomes the dendrite‐problem when employing metal‐anodes, and offers the possibility of using different liquid electrolytes at the anode and the cathode in a single cell. The battery concept is demonstrated with two low‐cost metal anodes (zinc and iron), two liquid cathodes (bromine and potassium ferricyanide), and one gaseous cathode (air/O₂) with a sodium‐ion solid electrolyte. This novel battery strategy with a mediator‐ion solid electrolyte is applicable to a wide range of electrochemical energy storage systems with a variety of cathodes, anodes, and mediator‐ion solid electrolytes.     

Electrochemical Energy Storage with a Reversible Nonaqueous Room‐Temperature Aluminum–Sulfur Chemistry

A reversible room‐temperature aluminum–sulfur (Al‐S) battery is demonstrated with a strategically designed cathode structure and an ionic liquid electrolyte. Discharge–charge mechanism of the Al‐S battery is proposed based on a sequence of electrochemical, microscopic, and spectroscopic analyses. The electrochemical process of the Al‐S battery involves the formation of a series of polysulfides and sulfide. The high‐order polysulfides (S_x^2?, x ≥ 6) are soluble in the ionic liquid electrolyte. Electrochemical transitions between S₆^2? and the insoluble low‐order polysulfides or sulfide (S_x ^2?, 1 ≤ x < 6) are reversible. A single‐wall carbon nanotube coating applied to the battery separator helps alleviate the diffusion of the polysulfide species and reduces the polarization behavior of the Al‐S batteries.     

Low‐Cost Hollow Mesoporous Polymer Spheres and All‐Solid‐State Lithium,Sodium Batteries

A practical, low‐cost synthesis of hollow mesoporous organic polymer (HMOP) spheres is reported. The electrochemical properties of Li⁺/Na⁺‐electrolyte membranes with these spheres substituting for oxide filler particles in poly(ethylene oxide) (PEO)‐filler composite are explored. The electrolyte membranes are mechanically robust, thermally stable to over 250 °C, and block dendrites from a metallic‐lithium/sodium anode. The Li⁺/Na⁺ transfer impedance across the lithium/sodium–electrolyte interface is initially acceptable at 65 °C and scavenging of impurities by the porous‐spheres filler lowers this impedance relative to that with Al₂O₃. All‐solid‐state Li/LiFePO₄ and Na/NaTi₂(PO4)₃ cells give stable discharge capacity of ≈130 and 80 mAh g^?1, respectively, at 0.5 C and 65 °C for 100 cycles.     

High‐Rate and Long Cycle‐Life Alloy‐Type Magnesium‐Ion Battery Anode Enabled Through (De)magnesiation‐Induced Near‐Room‐Temperature Solid–Liquid Phase Transformation

Resources used in lithium‐ion batteries are becoming more expensive due to their high demand, and the global cobalt market heavily depends on supplies from countries with high geopolitical risks. Alternative battery technologies including magnesium‐ion batteries are therefore desirable. Progress toward practical magnesium‐ion batteries are impeded by an absence of suitable anodes that can operate with conventional electrolyte solvents. Although alloy‐type magnesium‐ion battery anodes are compatible with common electrolyte solvents, they suffer from severe failure associated with huge volume changes during cycling. Consequently, achieving more than 200 cycles in alloy‐type magnesium‐ion battery anodes remains a challenge. Here an unprecedented long‐cycle life of 1000 cycles, achieved at a relatively high (dis)charge rate of 3 C (current density: 922.5 mA g^?1) in Mg₂Ga₅ alloy‐type anode, taking advantage of near‐room‐temperatures solid–liquid phase transformation between Mg₂Ga₅ (solid) and Ga (liquid), is demonstrated. This concept should open the way to the development of practical anodes for next‐generation magnesium‐ion batteries.     

An Efficient Separator with Low Li‐Ion Diffusion Energy Barrier Resolving Feeble Conductivity for Practical Lithium–Sulfur Batteries

Due to unprecedented features including high‐energy density, low cost, and light weight, lithium–sulfur batteries have been proposed as a promising successor of lithium‐ion batteries. However, unresolved detrimental low Li‐ion transport rates in traditional carbon materials lead to large energy barrier in high sulfur loading batteries, which prevents the lithium–sulfur batteries from commercialization. In this report, to overcome the challenge of increasing both the cycling stability and areal capacity, a metallic oxide composite (NiCo₂O₄@rGO) is designed to enable a robust separator with low energy barrier for Li‐ion diffusion and simultaneously provide abundant active sites for the catalytic conversion of the polar polysulfides. With a high sulfur‐loading of 6 mg cm^?2 and low sulfur/electrolyte ratio of 10, the assembled batteries deliver an initial capacity of 5.04 mAh cm^?2 as well as capacity retention of 92% after 400 cycles. The metallic oxide composite NiCo₂O₄@rGO/PP separator with low Li‐ion diffusion energy barrier opens up the opportunity for lithium–sulfur batteries to achieve long‐cycle, cost‐effective operation toward wide applications in electric vehicles and electronic devices.     

Pseudo‐Zn–Air and Zn‐Ion Intercalation Dual Mechanisms to Realize High‐Areal Capacitance and Long‐Life Energy Storage in Aqueous Zn Battery

Aqueous zinc batteries are considered as promising alternatives to lithium ion batteries owing to their low cost and high safety. However, the developments of state‐of‐the‐art zinc‐ion batteries (ZIB) and zinc–air batteries (ZAB) are limited by the unsatisfied capacities and poor cycling stabilities, respectively. It is of significance in utilizing the long‐cycle life of ZIB and high capacity of ZAB to exploit advanced energy storage systems. Herein, a bulk composite of graphene oxide and vanadium oxide (V₅O₁₂·6H₂O) as cathode material for aqueous Zn batteries in a mild electrolyte is employed. The battery performance is demonstrated to arise from a combination of the reversible cations insertion/extraction in vanadium oxide and especially the electrochemical redox reactions on the surface functional groups of graphene oxide (named as pseudo‐Zn–air mechanism). Along with adjusting the hydroxyl content on the surface of graphene oxide, the specific capacity is significantly increased from 342 mAh g^?1 to a maximum of 496 mAh g^?1 at 100 mA g^?1. The surface‐controlled kinetics occurring in the bulk composite ensure a high areal capacity of 10.6 mAh cm^?2 at a mass loading of 26.5 mg cm^?2, and a capacity retention of 84.7% over 10 000 cycles at a high current density of 10 A g^?1.     

Selectively Wetted Rigid–Flexible Coupling Polymer Electrolyte Enabling Superior Stability and Compatibility of High‐Voltage Lithium Metal Batteries

Solid polymer electrolytes (SPEs) are considered to be the key to solve the safety hazards and cycling performance of liquid high‐voltage lithium metal batteries (HVLMBs), but still suffer from low conductivity and poor interfacial compatibility. Here, polyvinylidene fluoride–polyvinyl acetate‐based (PVDF–PVAC) rigid–flexible coupling SPE selectively wetted by a tetramethylene sulfone (TMS) is prepared for high‐performance and superior‐safety HVLMBs. The intermolecular interactions in such SPE significantly facilitate lithium‐ion conductivity and electrolyte/electrode interface wettability. Moreover, PVAC selectively wetted with the TMS enhances interface compatibility with Li anodes and high‐voltage LiCoO₂ cathodes. As a result, the as‐assembled LiCoO₂/lithium‐metal solid‐state batteries present excellent cyclability with 85% capacity retention after 200 cycles between 3.0 and 4.5 V at room temperature. Furthermore, pouch cells with the as‐prepared SPE exhibit brilliant safety and superior interfacial compatibility. This study offers a promising and general selectively wetted design strategy to handle the compatibility and safety issues in HVLMBs.