All-solid-state Lithium-sulfur Batteries Research Articles

Bridging the gap between academic research and industrial development in advanced all-solid-state lithium-sulfur batteries.

The energy storage and vehicle industries are heavily investing in advancing all-solid-state batteries to overcome critical limitations in existing liquid electrolyte-based lithium-ion batteries, specifically focusing on mitigating fire hazards and improving energy density. All-solid-state lithium-sulfur batteries (ASSLSBs), featuring earth-abundant sulfur cathodes, high-capacity metallic lithium anodes, and non-flammable solid electrolytes, hold significant promise. Despite these appealing advantages, persistent challenges like sluggish sulfur redox kinetics, lithium metal failure, solid electrolyte degradation, and manufacturing complexities hinder their practical use. To facilitate the transition of these technologies to an industrial scale, bridging the gap between fundamental scientific research and applied R&D activities is crucial. Our review will address the inherent challenges in cell chemistries within ASSLSBs, explore advanced characterization techniques, and delve into innovative cell structure designs. Furthermore, we will provide an overview of the recent trends in R&D and investment activities from both academia and industry. Building on the fundamental understandings and significant progress that has been made thus far, our objective is to motivate the battery community to advance ASSLSBs in a practical direction and propel the industrialized process.

Regulate transportation of ions and polysulfides in all-solid-state Li-S batteries using ordered-MOF composite solid electrolyte.

A dilemma arises when striving to balance the maximum desired ion conductivity and minimize the undesired lithium polysulfide shuttling effect for all-solid-state lithium-sulfur batteries (ASSLSBs). Here, we introduce a strategy of using ordered MIL-125-NH2 as fillers for poly(ethylene oxide)-based electrolytes to simultaneously regulate the transportation of lithium ions and polysulfides. When compared to electrolytes lacking metal-organic frameworks (MOFs) and those containing disordered MOFs, the electrolyte featuring an ordered-MOF structure, denoted as three-dimensional (3D) MPPL composite solid electrolyte (CSE), exhibits the highest ion conductivity of 8.3 × 10-4 siemens per centimeter at 60°C. As a result, pouch-type ASSLSBs with 3D MPPL CSE maintains stable cycling for 400 cycles at 0.5 C at 60°C, showcasing the successful implementation of this strategy in simultaneously regulating ion and polysulfide transport. This approach opens up alternative avenues to achieve high-performance ASSLSBs with exceptional energy density.

In Situ Construction of LiF-Li3N-Rich Interface Contributed to Fast Ion Diffusion in All-Solid-State Lithium-Sulfur Batteries.

All-solid-state lithium-sulfur batteries (ASSLSBs) have attracted wide attention due to their ultrahigh theoretical energy density and the ability of completely avoiding the shuttle effect. However, the further development of ASSLSBs is limited by the poor kinetic properties of the solid electrode interface. It remains a great challenge to achieve good kinetic properties, by common strategies to substitute sulfur-transition metal and organosulfur composites for sulfur without reducing the specific capacity of ASSLSBs. In this study, a sulfur-(Ketjen Black)-(bistrifluoromethanesulfonimide lithium salt) (S-KB-LiTFSI) composite is constructed by introducing LiTFSI into the S-KB composite. The initial discharge capacity reaches up to 1483 mA h g-1, benefited from the improved ionic conductivity and diffusion kinetics of the S-KB-LiTFSI composite, where numerous LiF interphases with a Li3N component are in situ formed during cycling. Combined with DFT calculations, it is found that the migration barriers of LiF and Li3N are much smaller than that of the Li6PS5Cl solid electrolyte. The fast ionic conductors of LiF and Li3N not only enhance the Li+ transfer efficiency but also improve the interfacial stability. Therefore, the assembled ASSLSBs operate stably for 600 cycles at 200 mA g-1, and this study provides an effective strategy for the further development of ASSLSBs.

Constructing the Interconnected Charge Transfer Pathways in Sulfur Composite Cathode for All-Solid-State Lithium-Sulfur Batteries.

All-solid-state lithium-sulfur batteries (ASSLSBs) have advantageous features, such as high energy, low costs, enhanced safety, and no polysulfide dissolution. However, the use of sulfur as an active material in all-solid-state batteries is difficult because of its ionic and electrical insulating properties. Herein, we introduce a flower-shaped composite material consisting of MoS2 nanoparticles and sulfur, designed to establish interconnected ionic and electrical conduction pathways at the cathode. As a host material, MoS2 nanoparticles with a large specific surface area can coconduct Li ions and electrons, possessing the potential for effectively utilizing sulfur. However, MoS2 nanoparticles are prone to physical-electrochemical isolation by being surrounded by sulfur due to their crumpling property in the process of mixing and impregnation with sulfur. This problem is addressed by mildly milling the MoS2 nanoparticles and sulfur, after which melt diffusion is applied to generate uniform MoS2/sulfur composite materials to establish an interconnected conducting pathway within the composite. A sulfide solid electrolyte (Li6PS5Cl)-based ASSLSB incorporating the proposed MoS2/sulfur composite demonstrates a stable operation over 1000 cycles with a Coulombic efficiency of nearly 100%. This study emphasizes the significance of the structural design of the sulfur composite material on top of the intrinsic properties of the material for high-performance ASSLSBs.

Synergistic Interfacial Optimization for High-Sulfur-Content All-Solid-State Lithium-Sulfur Batteries.

Improving the sulfur content in the cathode is essential for achieving high-energy-density all-solid-state lithium-sulfur batteries (ASSLSBs). However, the complex multiinterfaces, akin to the short wooden planks that consist of the cask, severely limit the performance of ASSLSBs with high sulfur content. Since singular approaches fail to optimize these interfaces simultaneously, we propose a synergistic approach using a dual-doped sulfide solid electrolyte (Y2S3 and LiI) and an SbSn alloy sulfur host in this work. The incorporation of Y2S3 in the solid electrolyte serves to improve the electrolyte-electrolyte interfaces and enhance the ionic conductivity, while the inclusion of LiI helps stabilize the electrolyte-anode interface and suppress dendrite formation. Meanwhile, the SbSn alloy sulfur host facilitates the transfer of Li+ at the electrolyte-cathode interfaces. Consequently, the solid-solid interfaces are significantly improved, leading to impressive specific capacities in ASSLSBs with high sulfur content (>44% in the cathode composite) at room temperature (1163.5 mAh g-1) and at 60 °C (1408.7 mAh g-1) during the 50th cycle at 0.05C. This work presents a promising strategy for achieving practical high-performance ASSLSBs.

Effect of Borophene on the Electrochemical Performances of Li7P3S11 based AllSolid-State Lithium Sulfur Batteries

This study has investigated the effect of 2-dimensional (2D) beta borophene as a cathode additive for all-solid-state lithium-sulfur batteries. The comparisons have been carried out regarding the impact on ionic conductivity based on borophene content. Although the studies of borophene's contributions in the literature on the anode component, this study focuses on the cathode contribution for the first time. While MoS2 has been selected as the cathode active material, carbon black has been selected as the electrical conductor, and Li7P3S11 solid electrolyte has been synthesized as an ionic conductor in all-solid-state lithium-sulfur cells. Borophene has been synthesized from boron powder by the exfoliation method. As a cathodeactive material, MoS2, containing sulfur, and its 2D material nature, eliminates many of the disadvantages that sulfur exhibits when used alone. To investigate the effect of borophene on ionic conductivity in all-solid-state lithium-sulfur cells, multicomponent composite cathodes were prepared in (MoS2 / Conductive Carbon / Li7P3S11 + Borophene) overall compositions. According to the results, the specific capacity of the cells is affected negatively, while the stability of the cell is affected positively when increased the borophene amount.

High-areal-capacity all-solid-state Li-S battery enabled by dry process technology

All-solid-state lithium-sulfur batteries (ASSLSBs) based on sulfide solid electrolyte (SSE) hold great promise as the next-generation energy storage technology with great potential for high energy density and improved safety. However, the development of practical ASSLSBs is restricted by the scalable fabrication of sulfur cathode sheets with outstanding electrochemical performance, which remains a complex and challenging endeavor. Herein, we employ dry electrode technology to fabricate free-standing sulfur cathode sheets with both high sulfur content and loading. By utilizing polytetrafluoroethylene (PTFE) binders with unique fibrous morphologies in the dry electrodes, we achieved sulfur cathode sheets with high flexibility without compromising ionic and electronic conductivity. Remarkably, even with thickened dry cathode sheets featuring high sulfur loading of 4.5 mg cm-2, the sulfur cathodes exhibit high initial discharge capacity of 1114.8 mAh g-1 with good cycle stability and rate capability. Additionally, we successfully demonstrate the construction of sheet-type all-solid-state Li3.75Si/SSE/S cells, showcasing favorable electrochemical performance with a high reversible capacity of 1067.4 mAh g-1 after 30 cycles even at a high sulfur loading of 4.5 mg cm-2 and high current density of 1 mA cm-2 (0.2C). Our findings represent a demonstration of batteries coupled with high-capacity sulfur cathode and lithiated silicon anode exhibiting exceptional electrochemical performance. It also underscores the significant potential of dry-process technology in addressing the critical challenges associated with the practical production of ASSLSBs. This contribution propels ongoing endeavors in the development of next-generation energy storage systems.

An Electron/Ion Dual Conductive Integrated Cathode Using Cationic/Anionic Redox for High‐Energy‐Density All‐Solid‐State Lithium‐Sulfur Batteries

AbstractAll‐solid‐state lithium‐sulfur batteries (ASSLSB), composed of sulfur cathode and lithium metal anode with high theoretical capacity, have a potentially higher energy density by weight than a typical lithium‐ion battery (LIB). However, due to insulating sulfur, a relatively large proportion of electronic (carbon) and ionic (solid electrolyte) conductors are mixed for cathode fabrication, leading to inferior practical capacity. Herein, we report a novel integrated cathode Li2S‐LiI‐MoS2 which has relatively high electronic and ionic conductivities (the order of 10−4 S cm−1) without any carbon and solid electrolyte. The ASSLSB with integrated Li2S‐LiI‐MoS2 cathode delivers a remarkably high energy density of 1020 Wh kg−1 at the cathode level at room temperature. By applying precise X‐ray diffraction, pair distribution function analysis and X‐ray computed tomography, it is found that the formation of an ionic conducting phase composed mainly of LiI during discharge is responsible for the high rate capability. Furthermore, X‐ray absorption fine structure (XAFS) has also revealed the charge compensation mechanism and ascertained the involvement of both Mo 3d and S 3p orbitals during the charging and discharging process. It is believed the strategy will pave the way for developing high practical energy density at room temperature for all‐solid‐state batteries.

Investigation of the Reaction Mechanism of All-Solid-State Lithium-Sulfur Batteries by Operando in Situ Raman Spectroscopy

In recent years, all-solid-state lithium-sulfur batteries (ASSLSBs) with sulfide-based solid electrolytes have become a leading energy storage system due to their high ionic conductivity, ultra-high energy density, high safety, and low cost. There have been many challenges with the practical applications of Li-S batteries, however, as a result of the sluggish redox kinetics of lithium polysulfide (LPS) and its shuttling effects. Single-atom catalysts (SACs) with atomically dispersed metal-based sites have proven to be promising electrocatalysts in Li-S batteries. To construct the ASSLSBs, we design and develop MoS2/SnS2 and Fe SACs with MoS2/SnS2 cathodes, Li5.4PS4.4Cl1.6 sulfide-based solid electrolytes, and Li-In anode. In the current study, in situ Raman spectroscopy is used to determine the LPS species in the sulfur cathode with SACs and without SACs during the ASSLSBs cycling. The aim is to understand the charge-discharge mechanism and the influence of SACs on the dissolution of sulfur and poly-sulfides. As compared to the MoS2/SnS2 cathode, the Fe@MoS2/SnS2 cathode exhibit the highest catalytic LPS conversion. In addition, the Fe@MoS2/SnS2 cathode delivers a high discharge capacity and long-cycling performance with high coulombic efficiency in ASSLSBs. In operando in situ Raman studies, SACs provide important new insights into the charge-discharge reaction mechanism for the next generation of ASSLSBs.

Synergistic Defect Engineering and Interface Stability of Activated Carbon Nanotubes Enabling Ultralong Lifespan All-Solid-State Lithium-Sulfur Batteries.

Due to the high energy density, high safety, and low cost of sulfur, all-solid-state lithium-sulfur batteries (ASSLSBs) are considered one of the most promising next-generation energy storage devices. Nevertheless, the insufficient interfacial contact between solid electrolytes (SEs) and the active material of sulfur leads to inadequate electronic and ionic conduction, which increases interfacial resistance and capacity decay. In this paper, commercial carbon nanotubes (CNTs) are activated to form porous-CNTs (P-CNTs), which are used as sulfur-bearing matrix, forming S@P-CNTs-based composite cathodes for ASSLSBs. Compared with CNTs, P-CNTs possess a larger specific surface area and more oxygen-containing groups, providing enhanced interfacial contact and stability between S@P-CNTs and Li6PS5Cl SE, which are confirmed by scanning electron microscopy, X-ray photoelectron spectroscopy, and density functional theory calculations. Moreover, P-CNTs can form a 3D conductive network in the composite cathodes, facilitating the migration of electrons and the diffusion of ions, as well as improving the utilization of sulfur. As a result, the S@P-CNTs-based ASSLSBs display excellent electrochemical performances, especially rarely reported ultralong lifespan, which deliver a capacity of 1099.2 mA h g-1 at a current density of 1.34 mA cm-2, and remarkably maintain 70.4% of the initial capacity over 1400 cycles.

Insight into the role of crystallinity in oxide electrolytes enabling high-performance all-solid-state lithium-sulfur batteries

All-solid-state lithium-sulfur batteries (ASSLSBs) would be a promising candidate for the next-generation batteries due to the utilization of energy-dense electrodes and the non-flammable oxide solid-state electrolytes (SSEs), but still face great challenges such as low ionic conductivity of SSEs, poor interfacial contact and lithium (Li) dendrite propagation. Herein, we regulated the crystallinity degrees of the large-scale-fabricated Li1.5Al0.5Ge1.5(PO4)3 (LAGP) SSEs and explored the critical role of crystallinity optimization in reinforcing the basic properties of LAGP, developing a fundamental explanation for the inherent relation between the crystallinity and the performance of ASSLSBs. Benefiting from the optimized crystallinity (∼99.9 %), the large-scale-fabricated LAGP not only realizes the low surface roughness and high ionic conductivity (2.11 × 10−4 S cm−1) to improve interfacial contact and reduce resistance in ASSLSBs, but also possesses the dense internal structure with low porosity (1.49 %) to physically resist dendritic propagation and penetration. Consequently, the ASSLSB with the optimized LAGP delivers a high reversible capacity of 647.9 mAh/g even after 150 cycles at 0.1 C. This work confirms the significance of crystallinity in understanding the working mechanisms of oxide SSEs and developing future high-performance ASSLSBs.

Cross-Linked Solid Polymer-Based Catholyte for Solid-State Lithium-Sulfur Batteries

All-solid-state lithium-sulfur batteries (ASSLSBs) are a promising next-generation battery technology. They exhibit high energy density, while mitigating intrinsic problems such as polysulfide shuttling and lithium dendrite growth that are common to liquid electrolyte-based batteries. Among the various types of solid electrolytes, solid polymer electrolytes (SPE) are attractive due to their superior flexibility and high safety. In this work, cross-linkable polymers composed of pentaerythritol tetraacrylate (PETEA) and tri(ethylene glycol) divinyl ether (PEG), are incorporated into sulfur–carbon composite cathodes to serve a dual function as both a binder and electrolyte, as a so-called catholyte. The influence of key parameters, including the sulfur–carbon ratio, catholyte content, and ionic conductivity of the electrolyte within the cathode on the electrochemical performance, was investigated. Notably, the sulfur composite cathode containing 30 wt% of the PETEA-PEG copolymer catholyte achieved a high initial discharge capacity of 1236 mAh gS−1 at a C-rate of 0.1 and 80 °C.

Lattice Structures, Electronic Properties and Lithium-ion Transport Dynamics of Li10SnP2S12/Li interface

All-solid-state lithium-sulfur batteries (ASSLSBs) are considered one of the most desirable battery technologies thanks to their ultra-high theoretical capacity, low cost, and environmental friendliness. Li10GeP2S12 (LGPS), the existing solid electrolyte with the highest lithium-ion conductivity, is supposed to be replaced by Li10SnP2S12 (LSPS). Current LSPS-related applications and researches focus on structural properties, electrochemical performance, and interface regulation, while such topics as surface properties, interface properties, and the lithium-ion transport mechanism of LSPS interface with metal Li anode are rarely mentioned. Therefore, this paper investigates the interfacial structure, electrical properties, and lithium-ion transport of the LSPS/Li interface using the first-principles calculation method, observing the formation of a interface layer between LSPS and Li, which blocks the conduction of electrons, accelerates the diffusion of lithium-ion, and undermines their surface structures. Ab initio molecular dynamics (AIMD) simulations confirm that the interface benefits Li+ conduction. In addition, S and P in the surface layer of LSPS experience rapid diffusion and eventually penetrate deep into the metal Li anode to dent its integrity, which indicates less active material, disrupted anode surface structure, worse battery performance, and safety issues. This paper may theoretically guide the future application of LSPS in practical engineering.

Li2S-Based Composite Cathode with in Situ-Generated Li3PS4 Electrolyte on Li2S for Advanced All-Solid-State Lithium–Sulfur Batteries

All-solid-state lithium-sulfur batteries (ASSLSBs) are considered to be a promising solution for the next generation of energy storage systems due to their high theoretical energy density and improved safety. However, the practical application of ASSLSBs is hindered by several critical challenges, including the poor electrode/electrolyte interface, sluggish electrochemical kinetics of solid-solid conversion between S and Li2S in the cathode, and big volume changes during cycling. Herein, the 85(92Li2S-8P2S5)-15AB composite cathode featuring an integrated structure of a Li2S active material and Li3PS4 solid electrolyte is developed by in situ generating a Li3PS4 glassy electrolyte on Li2S active materials, resulting from a reaction between Li2S and P2S5. The well-established composite cathode structure with an enhanced electrode/electrolyte interfacial contact and highly efficient ion/electron transport networks enables a significant enhancement of redox kinetics and an areal Li2S loading for ASSLSBs. The 85(92Li2S-8P2S5)-15AB composite demonstrates superior electrochemical performance, exhibiting 98% high utilization of Li2S (1141.7 mAh g(Li2S)-1) with both a high Li2S active material content of 44 wt % and corresponding areal loading of 6 mg cm-2. Moreover, the excellent electrochemical activity can be maintained even at an ultrahigh areal Li2S loading of 12 mg cm-2 with a high reversible capacity of 880.3 mAh g-1, corresponding to an areal capacity of 10.6 mAh cm-2. This study provides a simple and facile strategy to a rational design for the composite cathode structure achieving fast Li-S reaction kinetics for high-performance ASSLSBs.

Understanding Electrochemical Reaction Mechanisms of Sulfur in All‐Solid‐State Batteries through Operando and Theoretical Studies **

AbstractDue to its outstanding safety and high energy density, all‐solid‐state lithium‐sulfur batteries (ASLSBs) are considered as a potential future energy storage technology. The electrochemical reaction pathway in ASLSBs with inorganic solid‐state electrolytes is different from Li‐S batteries with liquid electrolytes, but the mechanism remains unclear. By combining operando Raman spectroscopy and ex situ X‐ray absorption spectroscopy, we investigated the reaction mechanism of sulfur (S8) in ASLSBs. Our results revealed that no Li2S8, Li2S6, and Li2S4 were formed, yet Li2S2 was detected. Furthermore, first‐principles structural calculations were employed to disclose the formation energy of solid state Li2Sn (1≤n≤8), in which Li2S2 was a metastable phase, consistent with experimental observations. Meanwhile, partial S8 and Li2S2 remained at the full lithiation stage, suggesting incomplete reaction due to sluggish reaction kinetics in ASLSBs.

Understanding Electrochemical Reaction Mechanisms of Sulfur in All-Solid-State Batteries through Operando and Theoretical Studies.

Due to its outstanding safety and high energy density, all-solid-state lithium-sulfur batteries (ASLSBs) are considered as a potential future energy storage technology. The electrochemical reaction pathway in ASLSBs with inorganic solid-state electrolytes is different from Li-S batteries with liquid electrolytes, but the mechanism remains unclear. By combining operando Raman spectroscopy and ex situ X-ray absorption spectroscopy, we investigated the reaction mechanism of sulfur (S8 ) in ASLSBs. Our results revealed that no Li2 S8, Li2 S6, and Li2 S4 were formed, yet Li2 S2 was detected. Furthermore, first-principles structural calculations were employed to disclose the formation energy of solid state Li2 Sn (1≤n≤8), in which Li2 S2 was a metastable phase, consistent with experimental observations. Meanwhile, partial S8 and Li2 S2 remained at the full lithiation stage, suggesting incomplete reaction due to sluggish reaction kinetics in ASLSBs.

Multiscale Structural Engineering of Sulfur/Carbon Cathodes Enables High Performance All-Solid-State LiS Batteries.

Constructing all-solid-state lithium-sulfur batteries (ASSLSBs) cathodes with efficient charge transport and mechanical flexibility is challenging but critical for the practical applications of ASSLSBs. Herein, a multiscale structural engineering of sulfur/carbon composites is reported, where ultrasmall sulfur nanocrystals are homogeneously anchored on the two sides of graphene layers with strong SC bonds (denoted as S@EG) in chunky expanded graphite particles via vapor deposition method. After mixing with Li9.54 Si1.74 P1.44 S11.7 Cl0.3 (LSPSCL) solid electrolytes (SEs), the fabricated S@EG-LSPSCL cathode with interconnected "Bacon and cheese sandwich" feature can simultaneously enhance electrochemical reactivity, charge transport, and chemomechanical stability due to the synergistic atomic, nanoscopic and microscopic structural engineering. The assembled InLi/LSPSCL/S@EG-LSPSCL ASSLSBs demonstrate ultralong cycling stability over 2400 cycles with 100% capacity retention at 1 C, and a record-high areal capacity of 14.0mAhcm-2 at a record-breaking sulfur loading of 8.9mgcm-2 at room temperature as well as high capacities with capacity retentions of ≈100% after 600 cycles at 0 and 60°C. Multiscale structural engineered sulfur/carbon cathode has great potential to enable high-performance ASSLSBs for energy storage applications.

A Nickel-decorated porous graphitized carbon/sulfur cathode enabling excellent cycling stability of all-solid-state lithium-sulfur batteries

• A high electrical conductivity of Nickel-decorated porous graphitized carbon (Ni-PGC) host materials are prepared by a simple and effective calcination. • Ni-PGC-sulfur cathode realizes the fast redox kinetics of all-solid-state lithium-sulfur batteries. • Applying Ni-PGC-S material to all-solid-state Li-S battery can significantly improve the utilization of active materials. All-solid-state lithium-sulfur batteries (ASSLSBs) with high theoretical specific capacity and low cost are considered a promising electrochemical energy storage system. However, it suffers from large polarization, low sulfur utilization, and severe capacity decay, owing to the sluggish solid-solid reactions between sulfur and its discharging products (such as lithium sulfide, etc.). Herein, a Nickel-decorated porous graphitized carbon (Ni-PGC) is prepared using a one-step calcination method for the sulfur host in ASSLSBs with PEO-based solid electrolytes. The high specific surface area (638.2 m 2 g -1 ) of porous carbon structure with sufficient pore volume (0.69 cm 3 g -1 ) could uniformly disperse the active material (Sulfur). The metallic Nickel nanoparticles embedding in the porous network could significantly improve the electronic conductivity of composite cathode in ASSLSBs. As a result, the higher electrical conductivity of 8.22 S cm -1 is achieved from the Ni-PGC-S cathode, compared to 0.33 S cm -1 for the amorphous carbon-sulfur cathode. Furthermore, Li + diffusion coefficients (4.19×10 -11 cm 2 s -1 at the cathodic peak of 2.40 V, 7.54×10 -11 cm 2 s -1 at the cathodic peak of 2.05 V, and 2.69×10 -10 cm 2 s -1 at the anodic peak of 2.35 V) of the Ni-PGC-S cathode at 60 o C, are 11.11 times, 3.17 times and 2.17 times of the amorphous carbon-sulfur cathode without Ni doping. Therefore, the all-solid-state lithium-sulfur batteries assembled with the Ni-PGC-S cathode exhibit an extraordinary initial discharge capacity of 1311.3 mAh g -1 and a low cycling degradation (0.30 % per cycle) at 60 o C and 0.1 C. Even at 1 C, the battery delivers 375.8 mAh g -1 after 300 cycles.

A nitrogen-doped carbon skeleton derived from biomass as conductive agent for electrochemically stable cathode of all-solid-state lithium-sulfur batteries

All-solid-state lithium–sulfur batteries (ASSLSBs) have attracted much attention for the next-generation storage system due to their high energy density and safety. However, the oxidative and reductive decomposition of sulfide electrolyte during cycling causes limited application of ASSLSBs. Herein, we design a porous nitrogen-doped carbon skeleton derived from biomass material. The porous design minimizes the adverse effect of volume change of sulfur. Meanwhile, the introduction of N-doped carbon skeleton improves the electronic conductivity of composite cathode and the sulfur on this skeleton reduces direct contact between the electronic conductor and sulfide electrolyte, thus effectively promoting rapid electron transfer and inhibiting electron aggregation on the surface of electrolyte. Therefore, such an efficient electron transfer network notably suppresses the irreversible decomposition of electrolyte and enhances its cycling stability during charge/discharge process. The composite cathode delivers initial discharge capacity of 1145.9 mAh/g and a capacity retention of 88.14% after 100 cycles at 0.1 C.

Advances in sulfide-based all-solid-state lithium-sulfur battery: Materials, composite electrodes and electrochemo-mechanical effects

Sulfide-based all-solid-state lithium-sulfur batteries (ASSLSBs) have recently attracted great attention. The “shuttle effect” caused by the migration of polysulfides in conventional liquid lithium-sulfur batteries could be eliminated. Therefore, the utilization of active materials and cycling stability, as well as battery safety, can be significantly improved. Impressive progress has been made in the research of materials for sulfide-based ASSLSBs, including sulfide solid-state electrolytes (SSEs), sulfur-based cathode materials, and anode materials. However, challenges such as scalable fabrication of large-scale, high-areal capacity composite electrodes and robust, high-conductivity thin SSE films, as well as the serious electrochemo-mechanical issues in sulfur-based electrodes, still hinder the practical application and development of sulfide-based ASSLSBs. In this review, recent research progress on sulfide-based ASSLSBs materials is summarized and discussed. In addition, the challenges in the practical application of sulfide-based ASSLSBs, such as scalable composite electrodes/SSE membranes fabrication and complicated electrochemo-mechanical coupling effects, are also systematically overviewed.