Hybrid Lithium‐Sulfur Batteries with an Advanced Gel Cathode and Stabilized Lithium‐Metal Anode

The insulating nature of sulfur, polysulfide shuttle effect, and lithium‐metal deterioration cause a decrease in practical energy density and fast capacity fade in lithium‐sulfur (Li‐S) batteries. This study presents an integrated strategy for the development of hybrid Li‐S batteries based on a gel sulfur cathode, a solid electrolyte, and a protective anolyte composed of a highly concentrated salt electrolyte containing mixed additives. The dense solid electrolyte completely blocks polysulfide diffusion, and also makes it possible to investigate the cathode and anode independently. This gel cathode effectively traps the polysulfide active material while maintaining a low electrolyte to sulfur ratio of 5.2 mL g^?1. The anolyte effectively protects the Li metal and suppresses the consumption of liquid electrolyte, enabling stable long‐term cycling for over 700 h in Li symmetric cells. This advanced design can simultaneously suppress the polysulfide shuttle, protect Li metal, and reduce the liquid electrolyte usage. The assembled hybrid batteries exhibit remarkably stable cycling performance over 300 cycles with high capacity. Finally, surface‐sensitive techniques are carried out to directly visualize and probe the interphase formed on the surface of the Li_1.5Al_0.5Ge_1.5(PO₄)₃ (LAGP) pellet, which may help stabilize the solid–liquid interface.     

Understanding the Reactivity of a Thin Li1.5Al0.5Ge1.5(PO4)3 Solid‐State Electrolyte toward Metallic Lithium Anode

The thickness of solid‐state electrolytes (SSEs) significantly affects the energy density and safety performance of all‐solid‐state lithium batteries. However, a sufficient understanding of the reactivity toward lithium metal of ultrathin SSEs (<100 µm) based on NASICON remains lacking. Herein, for the first time, a self‐standing and ultrathin (70 µm) NASICON‐type Li_1.5Al_0.5Ge_1.5(PO₄)₃ (LAGP) electrolyte via a scalable solution process is developed, and X‐ray photoelectron spectroscopy reveals that changes in LAGP at the metastable Li–LAGP interface during battery operation is temperature dependent. Severe germanium reduction and decrease in LAGP particle size are detected at the Li–LAGP interface at elevated temperature. Oriented plating of lithium metal on its preferred (110) face occurs during in situ X‐ray diffraction cycling.     

Constructing Multifunctional Interphase between Li1.4Al0.4Ti1.6(PO4)3 and Li Metal by Magnetron Sputtering for Highly Stable Solid‐State Lithium Metal Batteries

Due to high ionic conductivity and low cost, Li_1.4Al_0.4Ti_1.6(PO₄)₃ (LATP) has emerged as a promising solid‐state electrolyte for next‐generation lithium (Li) metal solid‐state batterie with high safety performance and energy density. However, the extremely high impedance and surface instability of LATP with Li metal retard its practical application. Herein, a novel method is proposed to construct an ultrathin ZnO layer that is tightly coated on the LATP pellets, surface (ZnO@LATP) via magnetron sputtering, which in situ reacts with Li to form a low electronic conductivity and multifunctional solid electrolyte interphase (SEI). The formed SEI can not only effectively lower the interfacial resistance, but also overcome the side reactions of LATP with the Li metal anode and suppress the Li dendrite growth. Specifically, the interface resistance decreases from 80 554 to 353 Ω and the overpotential reduces from 1 V to 20 mV. As a result, the Li/ZnO@LATP@ZnO/Li symmetric batteries can stably cycle for more than 2000 h without short circuit at 0.05 mA cm^?2 and Li/ZnO@LATP/LiFePO₄ batteries show excellent cycle stability for 200 cycles at 0.1 C. This work highlights the significance of multifunctional interphase between LATP and Li metal for improvement of interfacial impedance and instability.     

An Air‐Stable and Dendrite‐Free Li Anode for Highly Stable All‐Solid‐State Sulfide‐Based Li Batteries

Li metal is a promising anode material for all‐solid‐state batteries, owing to its high specific capacity and low electrochemical potential. However, direct contact of Li metal with most solid‐state electrolytes induces severe side reactions that can lead to dendrite formation and short circuits. Moreover, Li metal is unstable when exposed to air, leading to stringent processing requirements. Herein, it is reported that the Li₃PS₄/Li interface in all‐solid‐state batteries can be stabilized by an air‐stable Li_xSiS_y protection layer that is formed in situ on the surface of Li metal through a solution‐based method. Highly stable Li cycling for over 2000 h in symmetrical cells and a lifetime of over 100 cycles can be achieved for an all‐solid‐state LiCoO₂/Li₃PS₄/Li cell. Synchrotron‐based high energy X‐ray photoelectron spectroscopy in‐depth analysis demonstrates the distribution of different components within the protection layer. The in situ formation of an electronically insulating Li_xSiS_y protection layer with highly ionic conductivity provides an effective way to prevent Li dendrite formation in high‐energy all‐solid‐state Li metal batteries.     

A Concentrated Ternary‐Salts Electrolyte for High Reversible Li Metal Battery with Slight Excess Li

Li metal can potentially deliver much higher specific capacity than commercially used anodes. Nevertheless, because of its poor reversibility, abundant excess Li (usually more than three times) is required in Li metal batteries, leading to higher costs and decreased energy density. Here, a concentrated lithium bis(trifluoromethane sulfonyl) imide (LiTFSI)–lithium nitrate (LiNO₃)–lithium bis(fluorosulfonyl)imide (LiFSI) ternary‐salts electrolyte is introduced to realize a high stable Li metal full‐cell with only a slight excess of Li. LiNO₃ and LiFSI contribute to the formation of stable Li₂O–LiF‐rich solid electrolyte interface layers, and LiTFSI helps to stabilize the electrolyte under high concentration. Li metal in the electrolyte remains stable over 450 cycles and the average Coulombic efficiency reaches 99.1%. Moreover, with 0.5 × excess Li metal, the Coulombic efficiency of Li metal in the LiTFSI–LiNO₃–LiFSI reaches 99.4%. The electrolyte also presents high stability to the LiFePO₄ cathode, the capacity retention after 500 cycles is 92.0% and the Coulombic efficiency is 99.8%. A Li metal full‐cell with only 0.44 × excess Li is also assembled, it remains stable over 70 cycles and 83% of the initial capacity is maintained after 100 cycles.     

Hybrid and Aqueous Lithium‐Air Batteries

Lithium‐air (Li‐air) batteries have become attractive because of their extremely high theoretical energy density. However, conventional Li‐air cells operating with non‐aqueous electrolytes suffer from poor cycle life and low practical energy density due to the clogging of the porous air cathode by insoluble discharge products, contamination of the organic electrolyte and lithium metal anode by moist air, and decomposition of the electrolyte during cycling. These difficulties may be overcome by adopting a cell configuration that consists of a lithium‐metal anode protected from air by a Li⁺‐ion solid electrolyte and an air electrode in an aqueous catholyte. In this type of configuration, a Li⁺‐ion conducting “buffer” layer between the lithium‐metal anode and the solid electrolyte is often necessary due to the instability of many solid electrolytes in contact with lithium metal. Based on the type of buffer layer, two different battery configurations are possible: “hybrid” Li‐air batteries and “aqueous” Li‐air batteries. The hybrid and aqueous Li‐air batteries utilize the same battery chemistry and face similar challenges that limit the cell performance. Here, an overview of recent developments in hybrid and aqueous Li‐air batteries is provided and the factors that influence their performance and impede their practical applications, followed by future directions are discussed.     

Enhanced Stability of Li Metal Anodes by Synergetic Control of Nucleation and the Solid Electrolyte Interphase

Use of a protective coating on a lithium metal anode (LMA) is an effective approach to enhance its coulombic efficiency and cycling stability. Here, a facile approach to produce uniform silver nanoparticle‐decorated LMA for high‐performance Li metal batteries (LMBs) is reported. This effective treatment can lead to well‐controlled nucleation and the formation of a stable solid electrolyte interphase (SEI). Ag nanoparticles embedded in the surface of Li anodes induce uniform Li plating/stripping morphologies with reduced overpotential. More importantly, cross‐linked lithium fluoride‐rich interphase formed during Ag⁺ reduction enables a highly stable SEI layer. Based on the Ag‐LiF decorated anodes, LMBs with LiNi_1/3Mn_1/3Co_1/3O₂ cathode (≈1.8 mAh cm^?2) can retain >80% capacity over 500 cycles. The similar approach can also be used to treat sodium metal anodes. Excellent stability (80% capacity retention in 10 000 cycles) is obtained for a Na||Na₃V₂(PO₄)₃ full cell using a Na‐Ag‐NaF/Na anode cycled in carbonate electrolyte. These results clearly indicate that synergetic control of the nucleation and SEI is an efficient approach to stabilize rechargeable metal batteries.     

SiO2 Hollow Nanosphere‐Based Composite Solid Electrolyte for Lithium Metal Batteries to Suppress Lithium Dendrite Growth and Enhance Cycle Life

The low Coulombic efficiency and serious security issues of lithium (Li) metal anode caused by uncontrollable Li dendrite growth have permanently prevented its practical application. A novel SiO₂ hollow nanosphere‐based composite solid electrolyte (SiSE) for Li metal batteries is reported. This hierarchical electrolyte is fabricated via in situ polymerizing the tripropylene gycol diacrylate (TPGDA) monomer in the presence of liquid electrolyte, which is absorbed in a SiO₂ hollow nanosphere layer. The polymerized TPGDA framework keeps the prepared SiSE in a quasi‐solid state without safety risks caused by electrolyte leakage, meanwhile the SiO₂ layer not only acts as a mechanics‐strong separator but also provides the SiSE with high room‐temperature ionic conductivity (1.74 × 10^?3 S cm^?1) due to the high pore volume (1.49 cm³ g^?1) and large liquid electrolyte uptake of SiO₂ hollow nanospheres. When the SiSE is in situ fabricated on the cathode and applied to LiFePO₄/SiSE/Li batteries, the obtained cells show a significant improvement in cycling stability, mainly attributed to the stable electrode/electrolyte interface and remarkable suppression for Li dendrite growth by the SiSE. This work can extend the application of hollow nanooxide and enable a safe, efficient operation of Li anode in next generation energy storage systems.     

High‐Performance All‐Solid‐State Lithium–Sulfur Batteries Enabled by Amorphous Sulfur‐Coated Reduced Graphene Oxide Cathodes

Safety and the polysulfide shuttle reaction are two major challenges for liquid electrolyte lithium–sulfur (Li–S) batteries. Although use of solid‐state electrolytes can overcome these two challenges, it also brings new challenges by increasing the interface resistance and stress/strain. In this work, the interface resistance and stress/strain of sulfur cathodes are significantly reduced by conformal coating ≈2 nm sulfur (S) onto reduced graphene oxide (rGO). An Li–S full cell consisting of an rGO@S‐Li₁₀GeP₂S₁₂‐acetylene black (AB) composite cathode is evaluated. At 60 °C, the all‐solid‐state Li–S cell demonstrates a similar electrochemical performance as in liquid organic electrolyte, with high rate capacities of 1525.6, 1384.5, 1336.3, 903.2, 502.6, and 204.7 mA h g^?1 at 0.05, 0.1, 0.5, 1.0, 2.0, and 5.0 C, respectively. It can maintain a high and reversible capacity of 830 mA h g^?1 at 1.0 C for 750 cycles. The uniform distribution of the rGO@S nanocomposite in the Li₁₀GeP₂S₁₂‐AB matrix generates uniform volume changes during lithiation/delithiation, significantly reducing the stress/strain, thus extending the cycle life. Minimization of the stress/strain of solid cells is the key for a long cycle life of all‐solid‐state Li–S batteries.     

A Metal Organic Framework Derived Solid Electrolyte for Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) are currently considered as promising candidates for next‐generation energy storage technologies. However, their practical application is hindered by the critical issue of the polysulfide‐shuttle. Herein, a metal organic framework (MOF)‐derived solid electrolyte is presented to address it. The MOF solid electrolyte is developed based on a Universitetet i Oslo (UIO) structure. By grafting a lithium sulfonate (‐SO₃Li) group to the UIO ligand, both the ionic conductivity and the polysulfide‐suppression capability of the resulting ‐SO₃Li grafted UIO (UIOSLi) solid electrolyte are greatly improved. After integrating a Li‐based ionic liquid (Li‐IL), lithium bis(trifluoromethanesulfonyl)imide in 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide, the resulting Li‐IL/UIOSLi solid electrolyte exhibits an ionic conductivity of 3.3 × 10^?4 S cm^?1 at room temperature. Based on its unique structure, the Li‐IL/UIOSLi solid electrolyte effectively restrains the polysulfide shuttle and suppresses lithium dendritic growth. Lithium–sulfur cells with the Li‐IL/UIOSLi solid electrolyte and a Li₂S₆ catholyte show stable cycling performance that preserves 84% of the initial capacity after 250 cycles with a capacity‐fade rate of 0.06% per cycle.     

A Versatile Sn‐Substituted Argyrodite Sulfide Electrolyte for All‐Solid‐State Li Metal Batteries

Sulfide‐based solid‐state electrolytes (SSEs) for all‐solid‐state Li metal batteries (ASSLMBs) are attracting significant attention due to their high ionic conductivity, inherently soft properties, and decent mechanical strength. However, the poor incompatibility with Li metal and air sensitivity have hindered their application. Herein, the Sn (IV) substitution for P (V) in argyrodite sulfide Li₆PS₅I (LPSI) SSEs is reported, in the preparation of novel LPSI‐xSn SSEs (where x is the Sn substitution percentage). Appropriate aliovalent element substitutions with larger atomic radius (R_<Sn> > R_<P>) provides the optimized LPSI‐20Sn electrolyte with a 125 times higher ionic conductivity compared to that of the LPSI electrolyte. The high ionic conductivity of LPSI‐20Sn enables the rich I‐containing electrolyte to serve as a stabilized interlayer against Li metal in sulfide‐based ASSLMBs with outstanding cycling stability and rate capability. Most importantly, benefiting from the strong Sn–S bonding in Sn‐substituted electrolytes, the LPSI‐20Sn electrolyte shows excellent structural stability and improved air stability after exposure to O₂ and moisture. The versatile Sn substitution in argyrodite LPSI electrolytes is believed to provide a new and effective strategy to achieve Li metal‐compatible and air‐stable sulfide‐based SSEs for large‐scale applications.     

Enhanced Cyclability of Lithium–Oxygen Batteries with Electrodes Protected by Surface Films Induced via In Situ Electrochemical Process

Although the rechargeable lithium–oxygen (Li–O₂) batteries have extremely high theoretical specific energy, the practical application of these batteries is still limited by the instability of their carbon‐based air‐electrode, Li metal anode, and electrodes, toward reduced oxygen species. Here a simple one‐step in situ electrochemical precharging strategy is demonstrated to generate thin protective films on both carbon nanotubes (CNTs), air‐electrodes and Li metal anodes simultaneously under an inert atmosphere. Li–O₂ cells after such pretreatment demonstrate significantly extended cycle life of 110 and 180 cycles under the capacity‐limited protocol of 1000 mA h g^?1 and 500 mA h g^?1, respectively, which is far more than those without pretreatment. The thin‐films formed from decomposition of electrolyte during in situ electrochemical precharging processes in an inert environment, can protect both CNTs air‐electrode and Li metal anode prior to conventional Li–O₂ discharge/charge cycling, where reactive reduced oxygen species are formed. This work provides a new approach for protection of carbon‐based air‐electrodes and Li metal anodes in practical Li–O₂ batteries, and may also be applied to other battery systems.     

Polysulfide‐Shuttle Control in Lithium‐Sulfur Batteries with a Chemically/Electrochemically Compatible NaSICON‐Type Solid Electrolyte

A NaSICON‐type Li⁺‐ion conductive membrane with a formula of Li_{1+ x} Y _x Zr_{2? x} (PO₄)₃ (LYZP) (x = 0–0.15) has been explored as a solid‐electrolyte/separator to suppress polysulfide‐crossover in lithium‐sulfur (Li‐S) batteries. The LYZP membrane with a reasonable Li⁺‐ion conductivity shows both favorable chemical compatibility with the lithium polysulfide species and exhibits good electrochemical stability under the operating conditions of the Li‐S batteries. Through an integration of the LYZP solid electrolyte with the liquid electrolyte, the hybrid Li‐S batteries show greatly enhanced cyclability in contrast to the conventional Li‐S batteries with the porous polymer (e.g., Celgard) separator. At a rate of C/5, the hybrid Li ||LYZP|| Li₂S₆ batteries developed in this study (with a Li‐metal anode, a liquid/LYZP hybrid electrolyte, and a dissolved lithium polysulfide cathode) delivers an initial discharge capacity of ≈1000 mA h g^?1 (based on the active sulfur material) and retains ≈90% of the initial capacity after 150 cycles with a low capacity fade‐rate of <0.07% per cycle.     

Interface‐Engineered All‐Solid‐State Li‐Ion Batteries Based on Garnet‐Type Fast Li+ Conductors

All‐solid‐state Li‐ion batteries based on Li₇La₃Zr₂O₁₂ (LLZO) garnet structures require novel electrode assembly strategies to guarantee a proper Li⁺ transfer at the electrode–electrolyte interfaces. Here, first stable cell performances are reported for Li‐garnet, c‐Li_6.25Al_0.25La₃Zr₂O₁₂, all‐solid‐state batteries running safely with a full ceramics setup, exemplified with the anode material Li₄Ti₅O₁₂. Novel strategies to design an enhanced Li⁺ transfer at the electrode–electrolyte interface using an interface‐engineered all‐solid‐state battery cell based on a porous garnet electrolyte interface structure, in which the electrode material is intimately embedded, are presented. The results presented here show for the first time that all‐solid‐state Li‐ion batteries with LLZO electrolytes can be reversibly charge–discharge cycled also in the low potential ranges (≈1.5 V) for combinations with a ceramic anode material. Through a model experiment, the interface between the electrode and electrolyte constituents is systematically modified revealing that the interface engineering helps to improve delivered capacities and cycling properties of the all‐solid‐state Li‐ion batteries based on garnet‐type cubic LLZO structures.     

Perovskite Membranes with Vertically Aligned Microchannels for All‐Solid‐State Lithium Batteries

Perovskite‐type solid‐state electrolytes exhibit great potential for the development of all‐solid‐state lithium batteries due to their high Li‐ion conductivity (approaching 10^?3 S cm^?1), wide potential window, and excellent thermal/chemical stability. However, the large solid–solid interfacial resistance between perovskite electrolytes and electrode materials is still a great challenge that hinders the development of high‐performance all‐solid‐state lithium batteries. In this work, a perovskite‐type Li_0.34La_0.51TiO₃ (LLTO) membrane with vertically aligned microchannels is constructed by a phase‐inversion method. The 3D vertically aligned microchannel framework membrane enables more effective Li‐ion transport between the cathode and solid‐state electrolyte than a planar LLTO membrane. A significant decrease in the perovskite/cathode interfacial resistance, from 853 to 133 Ω cm², is observed. It is also demonstrated that full cells utilizing LLTO with vertically aligned microchannels as the electrolyte exhibit a high specific capacity and improved rate performance.     

Efficient Li‐Ion‐Conductive Layer for the Realization of Highly Stable High‐Voltage and High‐Capacity Lithium Metal Batteries

Recently, a consensus has been reached that using lithium metal as an anode in rechargeable Li‐ion batteries is the best way to obtain the high energy density necessary to power electronic devices. Challenges remain, however, with respect to controlling dendritic Li growth on these electrodes, enhancing compatibility with carbonate‐based electrolytes, and forming a stable solid–electrolyte interface layer. Herein, a groundbreaking solution to these challenges consisting in the preparation of a Li₂TiO₃ (LT) layer that can be used to cover Li electrodes via a simple and scalable fabrication method, is suggested. Not only does this LT layer impede direct contact between electrode and electrolyte, thus avoiding side reactions, but it assists and expedites Li‐ion flux in batteries, thus suppressing Li dendrite growth. Other effects of the LT layer on electrochemical performance are investigated by scanning electron microscopy, electrochemical impedance spectroscopy, and galvanostatic intermittent titration technique analyses. Notably, LT layer‐incorporating Li cells comprising high‐capacity/voltage cathodes with reasonably high mass loading (LiNi_0.8Co_0.1Mn_0.1O₂, LiNi_0.5Mn_1.5O₄, and LiMn₂O₄) show highly stable cycling performance in a carbonate‐based electrolyte. Therefore, it is believed that the approach based on the LT layer can boost the realization of high energy density lithium metal batteries and next‐generation batteries.     

Designing Safe Electrolyte Systems for a High‐Stability Lithium–Sulfur Battery

Safety, nontoxicity, and durability directly determine the applicability of the essential characteristics of the lithium (Li)‐ion battery. Particularly, for the lithium–sulfur battery, due to the low ignition temperature of sulfur, metal lithium as the anode material, and the use of flammable organic electrolytes, addressing security problems is of increased difficulty. In the past few years, two basic electrolyte systems are studied extensively to solve the notorious safety issues. One system is the conventional organic liquid electrolyte, and the other is the inorganic solid‐state or quasi‐solid‐state composite electrolyte. Here, the recent development of engineered liquid electrolytes and design considerations for solid electrolytes in tackling these safety issues are reviewed to ensure the safety of electrolyte systems between sulfur cathode materials and the lithium‐metal anode. Specifically, strategies for designing and modifying liquid electrolytes including introducing gas evolution, flame, aqueous, and dendrite‐free electrolytes are proposed. Moreover, the considerations involving a high‐performance Li⁺ conductor, air‐stable Li⁺ conductors, and stable interface performance between the sulfur cathode and the lithium anode for developing all‐solid‐state electrolytes are discussed. In the end, an outlook for future directions to offer reliable electrolyte systems is presented for the development of commercially viable lithium–sulfur batteries.     

Ultrathin,Flexible Polymer Electrolyte for Cost‐Effective Fabrication of All‐Solid‐State Lithium Metal Batteries

All‐solid‐state batteries are promising candidates for the next‐generation safer batteries. However, a number of obstacles have limited the practical application of all‐solid‐state Li batteries (ASSLBs), such as moderate ionic conductivity at room temperature. Here, unlike most of the previous approaches, superior performances of ASSLBs are achieved by greatly reducing the thickness of the solid‐state electrolyte (SSE), where ionic conductivity is no longer a limiting factor. The ultrathin SSE (7.5 µm) is developed by integrating the low‐cost polyethylene separator with polyethylene oxide (PEO)/Li‐salt (PPL). The ultrathin PPL shortens Li⁺ diffusion time and distance within the electrolyte, and provides sufficient Li⁺ conductance for batteries to operate at room temperature. The robust yet flexible polyethylene offers mechanical support for the soft PEO/Li‐salt, effectively preventing short‐circuits even under mechanical deformation. Various ASSLBs with PPL electrolyte show superior electrochemical performance. An initial capacity of 135 mAh g^?1 at room temperature and the high‐rate capacity up to 10 C at 60 °C can be achieved in LiFePO₄/PPL/Li batteries. The high‐energy‐density sulfur cathode and MoS₂ anode employing PPL electrolyte also realize remarkable performance. Moreover, the ASSLB can be assembled by a facile process, which can be easily scaled up to mass production.     

Multifunctional Silanization Interface for High‐Energy and Low‐Gassing Lithium Metal Pouch Cells

Lithium (Li) metal has attracted unprecedented attention as the ultimate anode material for future rechargeable batteries, but the electrochemical behavior (such as Li dendrites and gassing problems) in real Li metal pouch cells has received little attention. To achieve realistic high‐energy Li metal batteries, the designed solid electrolyte interface to suppress both Li dendrites and catastrophic gassing problems is urgently needed at cell level. Here, an efficient multifunctional silanization interface (MSI) is proposed for high‐energy Li metal pouch cells. Such an MSI not only guides uniform nucleation and growth of Li metal but also suppresses interfacial parasitic reactions between Li metal and electrolyte. As a result, under harsh conditions (negative to positive electrode capacity ratio of 2.96 and electrolyte weight to cathode capacity ratio of 2.7 g Ah^?1), a long‐running lifespan (over 160 cycles with a capacity retention of 96% at 1 C), and low‐gassing behavior of realistic high‐energy Li metal pouch cell (1 Ah, 300 Wh kg^?1) is achieved. This work opens a promising avenue toward the commercial applications of 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.