Ceramic Solid-state Electrolyte Research Articles

Grain size and grain boundary strength: Dominative role in electro-chemo-mechanical failure of polycrystalline solid-state electrolytes

Solid-state batteries with lithium metal anode have been accepted extensively as the competitive option to fulfill the upping requirement for safe and efficient energy devices. Nevertheless, its wide-ranging application has been impeded by the failure of solid-state electrolyte (SSE) induced by development of lithium (Li) filament. Based on the nature of polycrystalline ceramic SSE with varying grain size and boundary strength, the constitutive equation coupled with electrochemical kinetics was applied to picture the propagation of damage and corresponding disintegration caused by the development of Li filament. Based on the results, we found that the stress generated along with the growth of Li filament spreads away via the opening and sliding of grain boundary. Thus, damage occurs along grain boundaries, of which propagation behavior and damage level are controlled by grain size. Especially, over-refinement and under-refinement of grains of SSE can cause flocculent damage with inordinate damage degree and accelerate the failure time of SSE, respectively. On the other hand, the failure time is powerfully prolongated through strengthening the grain boundary of SSE. Eventually, grain size of 0.2 μm and tensile strength of grain boundary of 0.8-time-of-grain are posted as the threshold to realize the postponed failure of NASICON-based SSE. Inspiringly, electro-chemo-mechanical model in this contribution is generally applicable to other type of ceramic SSE to reveal the failure process and provide the design guideline, fostering the improvement of solid-state batteries.

Phase Evolution and Crystallization Mechanism of Glass Ceramic Solid-State Electrolyte from In Situ Synchrotron X-ray Diffraction

Phase Evolution and Crystallization Mechanism of Glass Ceramic Solid-State Electrolyte from In Situ Synchrotron X-ray Diffraction

Preparation and performances of gallium-doped LLZO electrolyte with high ionic conductivity by rapid ultra-high-temperature sintering

Garnet-type Li7La3Zr2O12 (LLZO) is a promising solid-state electrolyte (SSE) for next generation lithium batteries due to its high Li+ conductivity and stability against lithium metal, especially the Li7−3xGaxLa3Zr2O12 (Ga-LLZO) is most valuable because of its high ionic conductivity (> 1 ×10−3 S cm−1). However, it is difficult to prepare high-quality Ga-LLZO by the traditional air ambient sintering. Herein, we develop a simple and efficient rapid ultra-high-temperature sintering (RUHTS) method to prepare high-conductivity Ga-LLZO ceramic SSE. It has been found that the as-prepared Ga-LLZO ceramic SSE with the composition of Li6.25Ga0.25La3Zr2O12 exhibits high relative density of 99%, good ionic conductivity of 1.48 × 10−3 S cm−1 and large critical current density of 0.5 mA cm−2 after sintering at 1200 °C for 2 min. In addition, the Ga-LLZO SSE shows good electrochemical stability and interfacial compatibility against Li metal. The assembled Li-Li symmetric cell represents a small interfacial impedance of 37 Ω cm2. In the same time, the Li/Ga-LLZO/LE+LMNCO full battery has a total impedance of 205 Ω cm2, and can deliver a first discharge capacity of 235.1 mAh g−1 at 0.5 C, and the capacity retention rate is 88.3% after 100 cycles. This indicates that the as-prepared Ga-LLZO has good application prospect in the Li-metal solid-state batteries (LMSSBs). Moreover, this method does not require the use of mother powder during preparation process, which will effectively reduce the waste of raw materials, save manufacture costs and be beneficial to quantity production of Ga-LLZO ceramic electrolyte.

Seawater Battery: Strategies to Enable High Performance

Renewable energy sources such as solar, wind, and tide energy have been implemented to decrease air pollution due to common fossil fuel-generated electricity [1]. However, those systems are intermittent; creating the need for an energy storage system (ESS) that stores over-generated energy for later use and effectively matches the power fluctuation generated because of the sporadic demand throughout the day [2]. A possible solution to this problem is to couple renewable sources with rechargeable batteries. The most widespread electrochemical battery in the market is Lithium-ion, owing to its high energy density and lifetime and capability to resist frequent changes in charging-discharging rates [3]. Nevertheless, the current battery industry already requires 50% of the world's available lithium [4]. Foremost, lithium-ion battery is composed of critical metals such as cobalt, nickel, and manganese. The anticipated growing demand for these metals will lead to their scarcity [5]. Therefore, this study aims to develop strategy to enable a sodium-ion battery based on soluble seawater sodium and address the electrochemical and engineering problems.Seawater batteries have an open cathode compartment that can utilizes Na+ infinite source in the ocean as the active material [6]. There are three main components in this open structure seawater battery design. First is the non-aqueous liquid electrolyte facilitating the sodium ions transfer and deposition on the anode compartment [7-8]. Subsequently, the solid-state electrolyte (SSE) enables the flow of sodium ions from the sweater cathode to the anode which is typically copper current collector [9]. Lastly, a current collector that provides reaction sites for cathode reactions that could be made of carbon-based materials, such as carbon paper, carbon felt, or carbon cloth [10].The Solid-state electrolyte is the component that requires the most attention. It must have high ionic conductivity to increase sodium-ions transfers and maintain good mechanical and physical properties as it represents the interface between cathode and anode, preventing the water from penetrating the anode compartment and short-circuiting the cell.To increase its ionic conductivity, it is necessary to reduce its thickness as much as possible. Through the palletization and sintering process, a ceramic SSE was fabricated with a thickness of ~ 250 µm and ionic conductivity of 0.62 mS/cm. Subsequently, symmetric cells (Na||SSE||Cu) were assembled to further test the pellet's performance. Cells that were tested under continuous charge/discharge cycling for 360 cycles showed stable charge capacity and high Coulombic efficiency (> 95%). Performance of full cells using seawater at the cathode was also demonstrated. Addressing various issues such as water permeation through the SSE, electrode corrosion, Na deactivation in the anode, and catalytic activity of the carbon cathodes are also investigated. Figure 1. Charge/discharge profile of a symmetric Na||SSE||Cu cell at a current density of 0.10 mA/cm2.

Insight into the integration way of ceramic solid-state electrolyte fillers in the composite electrolyte for high performance solid-state lithium metal battery

Reasonably combining ceramic solid-state electrolytes (SSEs) and polymer-based SSEs to create versatile composite SSEs has provided new enlightenment for the development of solid-state lithium metal batteries (SSLMBs). Here, different integration ways of Li6.4La3Zr1.4Ta0.6O12 (LLZTO) with an electrospinned 3D polyacrylonitrile (PAN) nanofiber and a polymer electrolyte formed by in-situ polymerization reaction were investigated. Firstly blending LLZTO ceramic with 3D PAN nanofiber followed by filling with polymer electrolyte into the spaces can offer the composite SSE a higher ionic conductivity (2.06 × 10−3 S·cm−1), the highest lithium transference number (0.5), and the highest mechanical strength (2.85 MPa). It can operate in Li symmetric cells over 1000 h with the potential of 0.07 V under a current density of 0.2 mA·cm−2, and make Li-LiFePO4 solid-state batteries (SSBs) excellent cycling performance (86.3% retention after 500 cycles at 0.5 C). It also delivers excellent electrochemical performances in 4.3 V or 4.5 V high voltage SSBs. In contrast, when LLZTO is absent or added through simple mixing without integration into PAN network, the electrochemical performances of SSEs and SSLMBs are inferior. Mechanism study suggests that the direct contact of LLZTO and succinonitrile (SN) will initiate the decomposition of SN, leading to the formation of a C=N-C barrier layer and further degradation of electrochemical performance.

Coordination-Assisted Precise Construction of Metal Oxide Nanofilms for High-Performance Solid-State Batteries.

The application of solid-state batteries (SSBs) is challenged by the inherently poor interfacial contact between the solid-state electrolyte (SSE) and the electrodes, typically a metallic lithium anode. Building artificial intermediate nanofilms is effective in tackling this roadblock, but their implementation largely relies on vapor-based techniques such as atomic layer deposition, which are expensive, energy-intensive, and time-consuming due to the monolayer deposited per cycle. Herein, an easy and low-cost wet-chemistry fabrication process is used to engineer the anode/solid electrolyte interface in SSBs with nanoscale precision. This coordination-assisted deposition is initiated with polyacrylate acid as a functional polymer to control the surface reaction, which modulates the distribution and decomposition of metal precursors to reliably form a uniform crack-free and flexible nanofilm of a large variety of metal oxides. For demonstration, artificial Al2O3 interfacial nanofilms were deposited on a ceramic SSE, typically garnet-structured Li6.5La3Zr1.5Ta0.5O12 (LLZT), that led to a significant decrease in the Li/LLZT interfacial resistance (from 2079.5 to 8.4 Ω cm2) as well as extraordinarily long cycle life of the assembled SSBs. This strategy enables the use of a nickel-rich LiNi0.83Co0.07Mn0.1O2 cathode to deliver a reversible capacity of 201.5 mAh g-1 at a considerable loading of 4.8 mg cm-2, featuring performance metrics for an SSB that is competitive with those of traditional Li-ion systems. Our study demonstrates the potential of solution-based routes as an affordable and scalable manufacturing alternative to vapor-based deposition techniques that can accelerate the development of SSBs for practical applications.

Insight into the Integration Way of Ceramic Solid-State Electrolyte Fillers in the Composite Electrolyte for High Performance Solid-State Lithium Metal Battery

Insight into the Integration Way of Ceramic Solid-State Electrolyte Fillers in the Composite Electrolyte for High Performance Solid-State Lithium Metal Battery

Enhanced Electrochemical Performance of Al- and Nb-Codoped LLZO Ceramic Powder and Its Composite Solid Electrolyte

Using a solid-state method, a Li6.25Al0.2La3Zr1.85Nb0.15O12 (LALZNO) ceramic solid-state electrolyte (SSE) was prepared by codoping with Al and Nb. A PEO-LiTFSI-20%LALZNO composite solid electrolyte (CSE) was prepared by incorporating LALZNO into a poly(ethylene oxide) (PEO) polymer using a solution casting method. Characterization of these materials shows that the lattice distortion caused by the codoping of Al and Nb into Li and Zr sites increases Li+ vacancy concentration and modifies Li+ transmission channels. The ionic conductivity of the LALZNO ceramic SSE at room temperature (RT, 25 °C) can reach 3.04 × 10–4 S/cm. When the LALZNO concentration in the LALZNO/PEO composite is 20 wt %, the PEO-LiTFSI-20%LALZNO CSE exhibits a maximum ionic conductivity (7.64 × 10–5 S/cm at RT), a wide electrochemical window (5.5 V vs Li/ Li+), and a high lithium-ion transport number (0.28). Testing a Li||PEO-LiTFSI-20%LALZNO||Li symmetrical cell shows that this solid electrolyte can be stably cycled for 500 h at 60 °C with a fixed areal capacity of 0.2 mAh/cm2. Furthermore, performance tests of the all-solid-state battery LiFePO4||PEO-LiTFSI-20%LALZNO||Li show that the CSE has excellent cycling and rate performance. This all-solid-state battery can stably cycle for more than 100 cycles under conditions of 60 °C and 0.2C. Furthermore, it retains a specific discharge capacity of 91.6% after 100 cycles, and its Coulombic efficiency is close to 100%.

Efficient Mutual-Compensating Li-Loss Strategy toward Highly Conductive Garnet Ceramics for Li-Metal Solid-State Batteries.

Garnet-type Li7La3Zr2O12 (LLZO) is a promising solid-state electrolyte (SSE) due to its high Li+ conductivity and stability against lithium metal. However, wide research and application of LLZO are hampered by the difficulty in sintering highly conductive LLZO ceramics, which is mainly attributed to its poor sinterability and the hardship of controlling the Li2O atmosphere at a high sintering temperature (∼1200 °C). Herein, an efficient mutual-compensating Li-loss (MCLL) method is proposed to effectively control the Li2O atmosphere during the sintering process for highly conductive LLZO ceramics. The Li6.5La3Zr1.5Ta0.5O12 (LLZTO) ceramic SSEs sintered by the MCLL method own high relative density (96%), high Li content (5.54%), high conductivity (7.19 × 10-4 S cm-1), and large critical current density (0.85 mA cm-2), equating those sintered by a hot-pressing technique. The assembled Li-Li symmetric battery and a Li-metal solid-state battery (LMSSB) show that the as-prepared LLZTO can achieve a small interfacial resistance (17 Ω cm2) with Li metal, exhibits high electrochemical stability against Li metal, and has broad potential in the application of LMSSBs. In addition, this method can also improve the sintering efficiency, avoid the use of mother powder, and reduce raw-material cost, and thus it may promote the large-scale preparation and wide application of LLZO ceramic SSE.

A commentary of Lithium-metal batteries in MIT Technology Review 2021

Battery technology is a major challenge restricting the development of the electric vehicle industry. Lithium-ion batteries have been widely applied in electric vehicles. The lithium-ion battery based on organic electrolyte is expensive, bulky with a low energy density, and flammable in the collision. These shortcomings of the batteries are reflected in electric vehicles by their high price, limited battery life, long charging time, and potential safety hazards, which are the main reasons why electric vehicles are not preferred. However, if these limitations are addressed by a breakthrough in battery technology, electric vehicles can be more competitive than gasoline vehicles. QuantumScape, a Silicon Valley startup, claims to have developed an emerging lithium-metal battery that overcomes these drawbacks of routine lithium-ion batteries with a ceramic solid-state electrolyte.①①Original source in Chinese: Q. Zhang, Lithium-metal batteries, Bulletin of National Natural Science Foundation of China. 35 (3) (2021) 407-408.

Electrolyte melt infiltration for scalable manufacturing of inorganic all-solid-state lithium-ion batteries.

All-solid-state lithium (Li) metal and lithium-ion batteries (ASSLBs) with inorganic solid-state electrolytes offer improved safety for electric vehicles and other applications. However, current inorganic ASSLB manufacturing technology suffers from high cost, excessive amounts of solid-state electrolyte and conductive additives, and low attainable volumetric energy density. Such a fabrication method involves separate fabrications of sintered ceramic solid-state electrolyte membranes and ASSLB electrodes, which are then carefully stacked and sintered together in a precisely controlled environment. Here we report a disruptive manufacturing technology that offers reduced manufacturing costs and improved volumetric energy density in all solid cells. Our approach mimics the low-cost fabrication of commercial Li-ion cells with liquid electrolytes, except that we utilize solid-state electrolytes with low melting points that are infiltrated into dense, thermally stable electrodes at moderately elevated temperatures (~300 °C or below) in a liquid state, and which then solidify during cooling. Nearly the same commercial equipment could be used for electrode and cell manufacturing, which substantially reduces a barrier for industry adoption. This energy-efficient method was used to fabricate inorganic ASSLBs with LiNi0.33Mn0.33Co0.33O2 cathodes and both Li4Ti5O12 and graphite anodes. The promising performance characteristics of such cells open new opportunities for the accelerated adoption of ASSLBs for safer electric transportation.

High performance sodium-sulfur batteries at low temperature enabled by superior molten Na wettability

Reducing the operating temperature of conventional molten sodium-sulfur batteries (∼350 °C) is critical to create safe and cost-effective large-scale storage devices. By raising the surface treatment temperature of lead acetate trihydrate, the sodium wettability on β''-Al2O3 improved significantly at 120 °C. The low temperature Na-S cell can reach a capacity as high as 520.2 mA h g-1 and stable cycling over 1000 cycles.

Synthesis and interface modification of oxide solid-state electrolyte-based all-solid-state lithium-ion batteries: Advances and perspectives

All-solid-state Li-ion batteries (ASSLiBs) are considered as promising next-generation energy storage devices, and the one that is based on oxide ceramic solid-state electrolyte (SSE) has attracted much attention for its high safety and stability in ambient conduction compared with that of used sulfur and polymer SSEs. However, the undeformable nature of the ceramic SSEs brings new issues such as poor interface bonding, limited contact area and limited cathode utilization for the ASSLiBs. In addition, the interface reaction and resistance are also obstacles for ASSLiBs application. In this review, we focus on the synthesis and electrochemical properties, interface modification and failure mechanism of ASSLiBs. Finally, perspectives of future researches on the ceramic SSEs-based ASSLiBs are discussed.

Printable, high-performance solid-state electrolyte films.

Current ceramic solid-state electrolyte (SSE) films have low ionic conductivities (10-8 to 10-5 S/cm ), attributed to the amorphous structure or volatile Li loss. Herein, we report a solution-based printing process followed by rapid (~3 s) high-temperature (~1500°C) reactive sintering for the fabrication of high-performance ceramic SSE films. The SSEs exhibit a dense, uniform structure and a superior ionic conductivity of up to 1 mS/cm. Furthermore, the fabrication time from precursor to final product is typically ~5 min, 10 to 100 times faster than conventional SSE syntheses. This printing and rapid sintering process also allows the layer-by-layer fabrication of multilayer structures without cross-contamination. As a proof of concept, we demonstrate a printed solid-state battery with conformal interfaces and excellent cycling stability. Our technique can be readily extended to other thin-film SSEs, which open previously unexplores opportunities in developing safe, high-performance solid-state batteries and other thin-film devices.

Local electrical degradations of solid-state electrolyte by nm-scale operando imaging of ionic and electronic transports

We report on degradation mechanisms of solid-state electrolyte (SSE) based on insights from nm-scale ionic conduction and electronic leakage for solid-state batteries. The significantly different local degradations revealed by nm-scale ionic and electronic transport imaging demonstrate the need for this nm-scale investigation. State-of-the-art lithium-ion conductive glass ceramic (Li2O–Al2O3–SiO2–P2O5–TiO2-GeO2) SSE shows at least two types of degradations spatially separated within the SSE, namely: (1) ionic conduction blocking and slight electronic leaking and (2) highly electronic shunting. Degradation was significantly suppressed by application of a Li-containing polyacrylonitrile thin coating on both sides of the ceramic SSE. With this coating, the ionic conduction was not reduced by the extensive cycling; instead, it improved slightly, although accompanied by a slight increase in electronic leaking. Our nm-scale transport imaging was achieved using an atomic force microscopy (AFM)-based half-cell setup and a logarithmic-scale amplifier with current sensitivity down to the fA (10−15 A) range. This half-cell setup consisting of an AFM-probe/SSE/Li structure can distinguish the ionic from the electronic current by flipping the bias-voltage polarity. This nm-scale operando imaging opens up novel characterization of ionic and electronic transport in the field of solid-state batteries.

A facile strategy to reconcile 3D anodes and ceramic electrolytes for stable solid-state Li metal batteries

Lithium metal batteries (LMBs) are regarded as the promising candidate for next-generation energy storage devices. Three-dimensional (3D) current collector is one of the effective anode materials for suppressing lithium (Li) dendrite and accommodating the variation of Li volume during the cycling. However, since the protruding 3D skeleton will also pierce the separator and cause catastrophic battery failure, the safety risk of short circuit still exists. The use of ceramic solid-state electrolyte (SSE) with high mechanical stability on the 3D anode can eliminate the danger of short circuit caused by Li dendrites or 3D skeleton. Nevertheless, in solid-state batteries, 3D anodes with highly electroactive areas suffer from considerable interface reactions and high interface impedance. Herein, we demonstrate a facile in-situ polymerized sealing (IPS) strategy to reconcile the 3D anode with ceramic SSE. The optimized battery configuration consists of 3D anode, in-situ polymerized interlayer and NASICON-type ceramic electrolyte of Li1.3Ti1.7Al0.3(PO4)3 (LATP). The in-situ polymerized interlayer not only significantly reduces the interfacial resistance between the 3D anode and LATP, but also encapsulates liquid electrolyte within the electrode for indispensable interface reactions and rapid Li+ transport. Resultingly, the symmetric cell of 3D Li | LATP | 3D Li delivered a long cycle life of 500 ​h. Moreover, this unique configuration can be paired with a LiNi0.6Co0.2Mn0.2O2 cathode and operate at room temperature, which exhibits excellent performances. This work provides a practical strategy for building safe and durable high-energy solid-state LMBs suitable for next-generation energy storage devices.

Improved Stability and Cyclability of Ceramic Solid Electrolyte by Coating Polymer

Rechargeable all-solid-state lithium (Li) metal batteries show improved safety and energy density compared to commercial Li-ion batteries using liquid electrolyte. As the key component of Li metal batteries, ceramic solid-state electrolyte has attracted great interest because of its high ion conductivity and great potential in interfacing with Li metal. Ceramic electrolyte has a more stable interface with Li metal than liquid electrolyte, but chemical reaction and Li dendrite growth at the electrolyte/Li interface are still significant, which causes device degradation and failure by cycling of Li plating and stripping. Unlike ceramic electrolyte, polymer electrolyte has a relatively stable interface with Li metal and better mechanical flexibility. Therefore, we introduced a polymer electrolyte coating to protect the ceramic electrolyte from direct contact with Li metal. The galvanotactic cycling Li plating/striping data on the devices with (without) the coating illustrates increased (decreased) overall conductivity and cyclability of the test cell by the cycling. Nanometer-scale ionic-transport imaging, based on atomic force microscopy, shows that cycling degrades the ceramic-only electrolyte by partially blocking ionic transport in areas; in contrast, cycling on the polymer-coated electrolyte improves ionic conductivity. Compared with the ceramic-only electrolyte, this novel polymer electrolyte coating on ceramic electrolyte shows less degradation when in contact with Li metal.

Oxygen Barrier Composite Membrane for Li-Air Battery Using Cuboid LiAlTiPO4 in Orthogonal Array

The Li-Air batteries which convert the electrochemical reactions of lithium and O2 into electrical energy have high theoretical gravimetric capacity (3861 mAh/gLi) that is ten times higher than that of lithium ion batteries (372 mAh/gc). Its potential to generate high energy density makes it a promising candidate to replace the lithium ion in the electric vehicle applications. To meet the requirements of the electric vehicle applications, the technical barriers that limit the cycle life such as oxygen permeation, electrolyte and cathode instability and low rate capability need to be overcome. Especially the consumption/de-activation of Li metal is accelerated when oxygen in cathode side moves into Li metal side through the electrolyte, which is one of the most significant factors preventing long-term operation of the system. Ceramic solid state electrolyte (SSE) separator has a remarkable gas blocking capability, but it should be thick and heavy (~0.3 mm) to be used as a gas barrier of Li-Air battery due to fragile property. This leads to a sharp decrease in energy density. We fabricated composite membrane consisting of micron-sized SSE particles arrayed in matrix shape and polymer grid. Here SSE particles and polymer have functions of lithium ion conduction and gas blocking, respectively. Cuboid particles were synthesized using silicon wafer template with cuboid pattern on it in size of 50 ~ 200um. Interface energy between particle and polymer was controlled by bimodal surface modification for better mechanical strength of membrane. Compared to amorphous particles, composite membrane using cuboid LATP particle has many benefits in high ionic conductivity, uniform thickness, light weight and flexibility. In this presentation, how to fabricate cuboid SSE particles in matrix shape array and characterization of composite membrane using it will be discussed.

Hot Pressed, Fiber-Reinforced (Li2S)70(P2S5)30 Solid-State Electrolyte Separators for Li Metal Batteries

Herein, we detail a hot pressing process that was used to fabricate dense, aramid-fiber-reinforced (Li2S)70(P2S5)30 glass–ceramic solid-state electrolyte (SSE) composites. Green SSE composites were hot pressed at 240 °C and 200 MPa so that the softened sulfide glass flowed around the rigid aramid fibers. The SSE composite with 10 wt % aramid fiber loading had a relative density of 99.8% and an ionic conductivity of 2.4 mS/cm. The composites were mechanically robust and flexible and showed no signs of macrocracking even after uniaxial compression to 3 MPa. Furthermore, the fabrication of freestanding films with 100 μm thickness was demonstrated. Scanning electron microscopy (SEM) revealed that the improved strength of the SSE composites was attributable to aramid fibers impeding the propagation of microcracks in the sulfide glass phase. Critical current density tests were performed on green and hot pressed SSE composite separators. A green sample shorted at 200 μA/cm2, a green sample made with preannealed ...

Polysulfide-Shuttle Control in Lithium-Sulfur and Sodium-Sulfur Batteries with Polymer-Coated Solid-State Electrolytes

The emerging lithium-sulfur (Li-S) batteries are gaining much attention as a promising next-generation energy storage technology.1 An analogous battery system with a sodium-sulfur chemistry has recently started to receive considerable attention as well.2 The electrochemical mechanism of the Li-S and Na-S batteries is quite similar and the charge-discharge processes of these two batteries involve the formation of soluble polysulfide intermediate species. Therefore, the development of both of these two battery systems is facing a critical obstacle due to the so-called “polysulfide-shuttle” behavior during cell operation.3, 4 Although a lot of efforts have been attempted to address such a challenge since it has been recognized many years ago, there is still a lack of reliable approaches that can fully prevent the polysulfide-shuttle without bringing any other negative effects to the Li-S or Na-S cell systems. Herein we present an alternative strategy to suppress the polysulfide-shuttle in Li-S and Na-S batteries with, respectively, a Li+-ion conductive and a Na+-ion conductive solid-state electrolytes.5, 6 However, the use of a solid electrolyte usually brings an additional challenge in maintaining an adequate ionic interface between the lithium or sodium anodes and the solid electrolytes. Therefore, a strategic approach by coating the solid-state electrolytes with a thin layer of a polymer has been developed. The polymer coating on the ceramic solid-state electrolyte offers a facile interface with the metal electrodes. Both the Li-S batteries and the Na-S batteries with the polymer-coated solid-electrolyte membrane show enhanced cycling stability. References X. W. Yu and A. Manthiram, Accounts Chem Res, 2017, 50, 2653-2660.A. Manthiram and X. W. Yu, Small, 2015, 11, 2108-2114.Y. X. Wang, B. W. Zhang, W. H. Lai, Y. F. Xu, S. L. Chou, H. K. Liu and S. X. Dou, Adv Energy Mater, 2017, 7, 1602829.A. Manthiram, X. W. Yu and S. Wang, Nat Rev Mater, 2017, 2, 16103.X. Yu and A. Manthiram, Adv Funct Mater, In Presss, doi.org/10.1002/adfm.201805996.X. W. Yu, Z. H. Bi, F. Zhao and A. Manthiram, Adv Energy Mater, 2016, 6, 1601392.