All-solid-state Batteries Research Articles

Understanding the Mechanical Behavior of Sulfide Solid Electrolyte Membranes for Practical Applications in All-Solid-State Batteries

All-solid-state batteries (ASSBs) hold great promise as next-generation energy storage systems due to their enhanced stability and high energy density compared to traditional lithium-ion batteries. This improvement stems from the use of a solid electrolyte (SE) instead of a highly volatile liquid electrolyte and the incorporation of a lithium metal anode. In general, sulfide-based SSBs require adequate pressurization conditions to establish an intimate interface between the solid particles, ensuring a continuous electron/ion conduction path. At the cell level, maintaining external stack pressure during operation is crucial to preserve conformal solid-solid contact. Furthermore, when scaling up, fabrication pressure should be carefully considered to enhance electrode densification without causing damage. In particular, the fabrication of thin, robust, and scalable SE membranes faces practical challenges due to a limited amount of polymeric binder and the low intrinsic ductility of SEs after densification. Understanding the mechanical behavior of these SE membranes is essential to ensure their structural stability during manufacturing.In this study, we systematically examined the mechanical properties of SE and SE membranes. The deformability of various types of sulfide SEs was assessed using a powder compaction test, departing from the commonly used indentation method. The yield pressure, which indicates the deformability of the SE powder, is influenced by the composition and synthesis conditions of the SEs. The stress-strain behaviors of the SE membranes were obtained through tensile and flexural tests for both as-prepared and pressed samples, respectively. The tensile and bending behaviors of the SE membranes strongly depend on the combination of the SE and polymeric binder. The utilization of a ductile SE and a rubbery polymer binder can enhance the flexibility and ductility of the membrane, leading to increased densification degree and low interfacial resistance even under lower fabrication pressure. The details of cell configuration, fabrication procedure, and the resulting performances of the cell will be discussed in this talk.

Solid-State Electrolytes: Probing Interface Regulation from Multiple Perspectives.

Solid-state electrolytes (SSEs), as the heart of all-solid-state batteries (ASSBs), are recognized as the next-generation energy storage solution, offering high safety, extended cycle life, and superior energy density. SSEs play a pivotal role in ion transport and electron separation. Nonetheless, interface compatibility and stability issues pose significant obstacles to further enhancing ASSB performance. Extensive research has demonstrated that interface control methods can effectively elevate ASSB performance. This review delves into the advancements and recent progress of SSEs in interfacial engineering over the past years. We discuss the detailed effects of various regulation strategies and directions on performance, encompassing enhancing Li+ mobility, reducing energy barriers, immobilizing anions, introducing interlayers, and constructing unique structures. This review offers fresh perspectives on the development of high-performance lithium-metal ASSBs.

Accelerating ionic–electronic percolation pathways via catecholate coordination of bioinspired-polymer dopamine in all-solid-state composite cathode

All-solid-state batteries (ASSBs) are becoming recognized as encouraging energy storage solutions due to their great energy density and superior safety features with sulfide-based solid-state electrolytes (SSEs). However, a major challenge is the unstable interface between conductive additives and SSEs, leading to a performance degradation. To overcome this obstacle, there is an urgent need to enhance ionic conductivity at the SSE–conductive additive interface and control interfacial kinetics to prevent undesired side reactions. Herein, we investigate the critical roles of self-polymerized dopamine coated vapor-grown carbon fibers (PDA@VGCF) in optimizing ionic–electronic percolation pathways in composite cathodes. The electrochemical properties, charge transfer kinetics, and interfacial side reactions of the composite cathodes consisting of LiNi0.8Co0.15Al0.05O2–Li6PS5Cl and VGCF as a conductive additive are thoroughly examined. In practice, the composite cathode employing PDA@VGCF exhibits superior to discharge capacity of 165.5 mAh g−1 (3.81 mAh cm−2) with outstanding capacity retention (≥96 %) at a current density of 0.1C (0.46 mA cm−2) compared to the composite cathode with VGCF (118.7 mAh g−1) over 100 cycles. The enhancement can be appropriate to the integration of a PDA surface layer onto VGCF, enhancing both Li+ diffusivity and the distribution of cathode components while suppressing undesirable capacity fading. This work proposes a promising approach for the surface modification of conductive additives in composite cathodes, thereby enhancing the electrochemical performance of sulfide-based ASSBs.

Atmospheric Influences on Li6PS5Cl Separators and the Resulting Ionic Conductivity for All-Solid-State Batteries

All-solid-state batteries (ASSBs), defined through a solid electrolyte, are emerging as a promising solution to address current challenges in energy and power density demands for electromobility. Within the various possible types of solid electrolytes, sulfide-based materials exhibit advantageous high ionic conductivities. However, due to the strong reactivity of sulfides, atmospheric exposure can lead to the formation of toxic hydrogen sulfide and additionally negatively impact the resulting battery performance. Both factors present key challenges for ASSB production, as they necessitate the development of a material-adapted, economically viable and safe process atmosphere. In the present study, the influence of different production atmospheres on sulfide-based solid electrolytes is experimentally investigated. For this purpose, sulfide sheets are exposed to defined atmospheres with dynamic air fluctuations at dew points ranging from −60 °C to 0 °C. The resulting ionic conductivities indicate a dependency on the prevailing dew point and exposure time with a discernible impact on performance even at dew points of −60 °C within atmospheres with constant air circulation. With the acquired results, a detailed and knowledge-based selection and design of dry room production atmospheres for ASSB cell assembly is possible, which is a necessary step for further industrialization.

Stabilizing the interface between high-Ni oxide cathode and Li6PS5Cl for all-solid-state batteries via dual-compatible halides

All-solid-state batteries (ASSBs) with enhanced safety are promising next-generation energy storage systems for electric vehicles. However, the utilization of ASSBs is hindered by the high interfacial resistances between high-Ni-oxide cathodes and sulfide solid electrolytes (SEs). Passivating interphases form on the cathode in contact with the SE upon charging, deteriorating the power capability and cyclability. Inspired by the excellent stability of halides at high voltages, herein, we propose the interfacial engineering of LiNixCoyMnzO2 (NCM) and Li6PS5Cl (LPSCl) using Li+-conductive halides with ʻdual compatibilityʼ. The charge-transport and interfacial resistances of the halide-coated NCM (NCM@halide) electrodes are analyzed using a transmission-line-based impedance model. Impedance analyses indicate that the interfacial halide nanolayers slightly increase the Li+-transport resistance, but the NCM@halide electrodes exhibit considerably lower interfacial resistances than bare NCM. Furthermore, the interfacial resistance is highly dependent on the halide composition: NCM@Li2ZrCl6 shows a lower interfacial resistance than NCM@Li3InCl6 and NCM@Li3YCl6, resulting in superior rate-capability and cycling stability. The composition-dependent electrochemical properties of the NCM@halide electrodes are discussed in terms of the dual compatibility of the halides with NCM and LPSCl. This study offers an effective approach for addressing the interfacial challenges of sulfide-based ASSBs with high-Ni oxide cathodes.

Paper‐like 100% Si Nanowires Electrodes Integrated with Argyrodite Li6PS5Cl Solid Electrolyte

Silicon anodes are a promising solution in all‐solid‐state batteries (ASSBs) due to minor lithium dendrite risk, high capacity, and low potential. Research on Si integration in ASSBs is still nascent, requiring a deep understanding of the interplay between electrode composition, structure, and performance. Here, we present the first study on 100% Si nanowires integrated with Li6PS5Cl solid electrolyte (SE). The anodes are paper‐like networks of aggregated Si nanowires produced by a slurry‐free method without carbon/binders. Despite the lack of any conductor, the Si anodes provide >2.5 Ah/g capacity at a high mass loading of 1.7 mg/cm2(~5 mAh/cm2), demonstrating sufficient electric and ionic conductivities. Electro‐chemo‐mechanical properties of the electrodes over (de)lithiation were probed through electrochemical impedance spectroscopy, ex‐situ microscopy, and in‐operando pressure regulation measurements. The lithiated electrode/SE interface was found to be electrochemically stable. Cross‐sectional microscopy at various states‐of‐charge confirmed the buffering effect of the anode porosity, resulting in the preservation of the electrode’s thickness after the first lithiation but a considerable shrinkage during delithiation, producing cracking and formation of the new interface. Capacity remains constant for five cycles, then decreases linearly up to 40 cycles. This is attributed to repeated fracture of the anode/electrolyte interface and the corresponding impedance increase

Rationally designed poly(propylene carbonate)-based electrolyte for dendrite-free all solid-state lithium metal batteries

Solid polymer electrolytes (SPEs)-based lithium metal batteries (LMBs) perform tremendous potential due to their high energy density and increased safety in comparison to conventional lithium-ion batteries. However, narrow electrochemical stability window (ESW), poor mechanical properties and confining current densities of traditional polyethylene oxide (PEO)-based electrolytes limit their ability to be compatible with high-energy density cathode materials. To tackle these challenges, a novel scalable SPE is hence designed for LMBs. This SPE is primarily composed of an allyl glycidyl ether modified poly(propylene carbonate) (PPCAGE) produced through metal-free polymerization method, an electrospun sulfonated poly(fluorenyl ether ketone) (SPFEK) framework and LiTFSI, which shows good mechanical property (tensile strength = 6.70 MPa and modulus of elasticity (MOE) = 82.5 MPa), high ionic conductivity (2.62 × 10−4 S cm−1 at 60 °C) and wide ESW (5.1 V). The all-solid-state batteries (ASSBs) are assembled with three different cathode materials including LFP, NCM811, and LCO to evaluate the application prospects of this SPE. The Li/LFP ASSB demonstrates a capacity of 101 mAh g−1 at 1 C, maintaining 78 % capacity retention after 500 loops. Even in the Li/LCO cell with a high cut off voltage of 4.5 V, the ASSB still achieves 132 mAh g−1 at 0.5 C, with 91 % capacity retention after 500 cycles. This SPFEK-PPCAGE/LiTFSI based electrolyte has promising application in energy-dense ASSBs.

Interfacial Stabilization by Prelithiated Trithiocyanuric Acid as an Organic Additive in Sulfide-Based All-Solid-State Lithium Metal Batteries.

Sulfide-based all-solid-state battery (ASSB) with a lithium metal anode (LMA) is a promising candidate to surpass conventional Li-ion batteries owing to their inherent safety against fire hazards and potential to achieve a higher energy density. However, the narrow electrochemical stability window and chemical reactivity of the sulfide solid electrolyte towards the LMA results in interfacial degradation and poor electrochemical performance. In this direction, we introduce an organic additive approach, that is the mixing of prelithiated trithiocyanuric acid, Li3TCA, with Li6PS5Cl, to establish a stable interface while preserving high ionic conductivity. Including 2.5 wt % Li3TCA alleviates the decomposition of the electrolyte on the lithium metal interface, decreasing the Li2S content in the solid-electrolyte interface (SEI) thus forming a more stable interface. In Li|Li symmetric cells, this strategy enables a rise in the critical current density from 1.0 to 1.9 mA cm-2 and stable cycling for over 750 hours at a high current density of 1.0 mA cm-2. This approach also enables Li|NbO-NCM811 full cell to operate more than 500 cycles at 0.3 C.

Interfacial Stabilization by Prelithiated Trithiocyanuric Acid as an Organic Additive in Sulfide‐Based All‐Solid‐State Lithium Metal Batteries

AbstractSulfide‐based all‐solid‐state battery (ASSB) with a lithium metal anode (LMA) is a promising candidate to surpass conventional Li‐ion batteries owing to their inherent safety against fire hazards and potential to achieve a higher energy density. However, the narrow electrochemical stability window and chemical reactivity of the sulfide solid electrolyte towards the LMA results in interfacial degradation and poor electrochemical performance. In this direction, we introduce an organic additive approach, that is the mixing of prelithiated trithiocyanuric acid, Li3TCA, with Li6PS5Cl, to establish a stable interface while preserving high ionic conductivity. Including 2.5 wt % Li3TCA alleviates the decomposition of the electrolyte on the lithium metal interface, decreasing the Li2S content in the solid‐electrolyte interface (SEI) thus forming a more stable interface. In Li|Li symmetric cells, this strategy enables a rise in the critical current density from 1.0 to 1.9 mA cm−2 and stable cycling for over 750 hours at a high current density of 1.0 mA cm−2. This approach also enables Li|NbO‐NCM811 full cell to operate more than 500 cycles at 0.3 C.

Innovative Sn-gradient sulfide solid electrolytes with superior air-stability for practical all-solid-state batteries

Sulfide solid electrolytes (SSEs) with high ionic conductivity and mechanical flexibility are considered promising Li+ transport media for all-solid-state batteries (ASSBs). However, susceptibility to moisture originating from their crystal structures degrades their inherent superior properties. In this study, we synthesized core–shell structured SSEs by inducing the growth of compounds with moisture-stable SnS44− units on the surface of Li6PS5Cl (LPSC). This Li10SnP2S12 (LSPS)@LPSC showed > 30 times higher Li+ conductivity than LPSC after exposure to dry room environment for 2 h. Additionally, the hydrolysis reaction was effectively inhibited in LSPS@LPSC, resulting in not only significant reduction of hydrogen sulfide (H2S) gas release, but the onset of its generation was also more delayed than in LPSC. Also, in LSPS@LPSC, the inhibition of P-O bond formation after moisture exposure contributes to retention of mechanical properties, as demonstrated by nano-indentation measurements: hardness changes from 1.42 GPa to 1.50 GPa for LSPS@LPSC versus from 1.21 GPa to 1.62 GPa for LPSC (dew point of −7.5 °C, 5 min). Furthermore, the Li(Ni0.8Co0.1Mn0.1)O2 cell with LSPS@LPSC exhibited excellent cycling stability comparable to that of LPSC under typical external pressure (30 MPa), and more remarkably, it showed superior cycle retention than LPSC cell under ultra-low external pressure (∼0.3 MPa).

Exploring superionic conduction in lithium oxyhalide solid electrolytes considering composition and structural factors

Lithium (Li) oxyhalides have emerged as promising solid electrolyte candidates for all-solid-state batteries (ASSBs) due to their superior ionic conductivity and excellent cathode capability. However, the mechanism of Li transport in oxyhalides has remained unclear due to the complex nature of these compounds, which often comprise multiple phases such as crystalline and amorphous structures. Herein, a first-principles study using density functional theory and ab initio molecular dynamic simulation is performed to gain a theoretical insight into the structural behavior and conduction pathway in oxyhalide electrolytes. Li2.5ZrCl5.5O0.5 electrolyte, as a case of study, is comprehensively investigated by considering various phases. It’s revealed that the P3̅m1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\rm{P}}\\bar{3}{\\rm{m}}1$$\\end{document} phase is energetically more stable and exhibits one order of magnitude higher Li conductivity compared to the C2/m phase among potential crystalline phases (1.63 mS cm−1 versus 0.24 mS cm−1 at room temperature). Interestingly, an amorphous phase with even higher ionic conductivity (~40 mS cm−1) can be generated by creating LiCl-deficient Li-Zr-O-Cl compounds. The remarkably high ionic conductivity suggests that the amorphous structure is likely the dominant conducting pathway, facilitating fast Li transport due the weak bonding between Li and other atoms. Cl anion mobility is also observed in the amorphous phase through mean square displacement (MSD) calculation, although further analyses revealed this to be localized vibration. This study sheds light on the nature of oxychloride structures and promotes a deeper understanding of the superionic conduction mechanism in oxychlorides, which will contribute to the development of advanced solid electrolytes and ASSBs.

An Effective Catholyte for Sulfide-Based All-Solid-State Batteries Utilizing Gas Absorbents.

All-solid-state batteries (ASSBs) possess the advantage of ensuring safety while simultaneously maximizing energy density, making them suitable for next-generation battery models. In particular, sulfide solid electrolytes (SSEs) are viewed as promising candidates for ASSB electrolytes due to their excellent ionic conductivity. However, a limitation exists in the form of interfacial side reactions occurring between the SSEs and cathode active materials (CAMs), as well as the generation of sulfide-based gases within the SSE. These issues lead to a reduction in the capacity of CAMs and an increase in internal resistance within the cell. To address these challenges, cathode composite materials incorporating zinc oxide (ZnO) are fabricated, effectively reducing various side reactions occurring in CAMs. Acting as a semiconductor, ZnO helps mitigate the rapid oxidation of the solid electrolyte facilitated by an electronic pathway, thereby minimizing side reactions, while maintaining electron pathways to the active material. Additionally, it absorbs sulfide-based gases, thus protecting the lithium ions within CAMs. In this study, the mass spectrometer is employed to observe gas generation phenomena within the ASSB cell. Furthermore, a clear elucidation of the side reactions occurring at the cathode and the causes of capacity reduction in ASSB are provided through density functional theory calculations.

Rational design of hybrid electrolyte for all-solid-state lithium battery based on investigation of lithium-ion transport mechanism

Lithium all-solid-state batteries (ASSBs) are a promising technology for achieving high energy density, long cycle life, and safe rechargeable battery systems. Among these, Li ASSBs using solid polymer electrolytes (SPEs) have gained attention owing to their processability, lightweight nature, flexibility, and favorable electrode contacts. However, SPEs have low ionic conductivity, low Li+ transference number, and lack mechanical strength, limiting cell performance. Therefore, the present study focuses on the development of hybrid polymer electrolytes (HPEs) by incorporating Li1+xAlxTi2-x(PO4)3 (LATP) of Li/Na superionic conductor-type materials into SPEs. The HPEs with LATP 10 wt% exhibited significant improvements with an ionic conductivity of 7.23 × 10−4 S cm−1 at 45 °C and a Li+ transference number of 0.61. Density functional theory calculations supported the enhanced Li-ion migration through the polymer-LATP interface achieved by the optimized LATP content. The addition of LATP particles enhanced the mechanical strength of the electrolytes, effectively suppressing dendrite growth, resulting in a 66.65 % capacity retention after 320 cycles, highlighting the crucial role of high-performance HPEs in advanced ASSBs. By addressing the limitations of SPEs, HPEs offer promising opportunities to unlock the full potential of solid-state battery technologies for various energy storage systems.

High-Voltage Long-Cycling All-Solid-State Lithium Batteries with High-Valent-Element-Doped Halide Electrolytes.

All-solid-state batteries (ASSBs) have garnered considerable attention as promising candidates for next-generation energy storage systems due to their potentially simultaneously enhanced safety capacities and improved energy densities. However, the solid future still calls for materials with high ionic conductivity, electrochemical stability, and favorable interfacial compatibility. In this study, we present a series of halide solid-state electrolytes (SSEs) utilizing a doping strategy with highly valent elements, demonstrating an outstanding combination of enhanced ionic conductivity and oxidation stability. Among these, Li2.6In0.8Ta0.2Cl6 emerges as the standout performer, displaying a superionic conductivity of up to 4.47 mS cm-1 at 30 °C, along with a low activation energy barrier of 0.321 eV for Li+ migration. Additionally, it showcases an extensive oxidation onset of up to 5.13 V (vs Li+/Li), enabling high-voltage ASSBs with promising cycling performance. Particularly noteworthy are the ASSBs employing LiCoO2 cathode materials, which exhibit an extended cyclability of over 1400 cycles, with 70% capacity retention under 4.6 V (vs Li+/Li), and a capacity of up to 135 mA h g-1 at a 4 C rate, with the loading of active materials at 7.52 mg cm-2. This study demonstrates a feasible approach to designing desirable SSEs for energy-dense, highly stable ASSBs.

Towards a scalable production of β-Li3PS4-based all-solid-state batteries: Optimizing pressing parameters of the tape-casted solid electrolyte and composite cathode films

Pressing of all-solid-state batteries (ASSBs) components is one of the most important processes for scalable production. Henceforth, pressing parameters (pressure and temperature) for β-Li3PS4 (β-LPS) solid electrolyte (SE) separator films and LiNi0.6Co0.2Mn0.2 (NCM622)/β-LPS composite cathode films prepared by a slurry-based process were investigated and optimized. Compression of the β-LPS film at a temperature of 100 °C led to higher ionic conductivity than cold-pressed films. Raman and X-ray photoelectron spectroscopic analyses revealed no changes in the chemical nature of β-LPS material after hot pressing. Interestingly, time-of-flight secondary ion mass spectrometric (ToF-SIMS) analyses indicated a binder enrichment in the upper layers of the hot-pressed film. In a similar trend, increasing compression and temperature resulted in higher densification of NCM622/β-LPS composite cathode films. Based on galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) measurements, hot-pressed composite cathode at 200 MPa/100 °C exhibited a higher coverage percent of catholyte on cathode active material and a greater Li+ diffusion coefficient (DLi+) than cold-pressed one at 200 MPa/20 °C. Cycling tests of “Li–In│β-LPS│NCM/β-LPS” ASSBs with hot-pressed films displayed better cycling performance than that with cold-pressed ones, attributed to the higher concentration of electrochemically active NCM in close contact with β-LPS catholyte.

Recent Progress of In‐Depth Analysis Techniques for Si Anodes in Sulfide‐Based All‐Solid‐State Batteries: A Concise Overview and Future Perspective

AbstractThe utilization of Si anode in sulfide‐based all‐solid‐state batteries (ASSBs) has gained more research attention in recent years to overcome the interface challenges associated with ASSB‐containing Li metal anode. However, the volume expansion feature of the Si, stress/strain evolution inside the electrode, and the parasitic side reaction at the Si/sulfide SE interface are the most predominant limiting factors for practical device applications. It is necessary to investigate and understand the interface challenges through in‐depth analysis in real‐time battery operation to design highly efficient ASSBs for commercial device applications. Hence, this perspective paper provides a summary of the characterization tools and the analysis results related to the Si/sulfide SE interface. Moreover, in this perspective, we emphasize the importance of further investigation of the interface through more advanced in‐depth/operando analysis tools to gain insightful information about the anodic interface, which could be useful for the researchers to design efficient research strategies for solving the challenging issues associated with the anodic interface.

Exploring optimal cathode composite design for high-performance all-solid-state batteries

All-solid-state batteries (ASSBs) have attracted considerable attention due to their high stability, offering a safer alternative to currently used batteries. Extensive research has been conducted to improve cathode part performance. However, the conventional hand mixing (HM) process results in inhomogeneous particle distribution, causing poor interparticle contact due to uneven stress distribution, and the solution process causes unwanted solid electrolyte (SE) deterioration when using a polar solvent although it ensures uniform SE distribution. To overcome these limitations, based on the design rule considering SE surface coverage of less than 100 %, we propose a cathode/SE composite, showing decent ionic/electronic conductivities, uniform SE distribution, and intimate interparticle contact, achievable through a mass-producible mechanical mixing (MM) process. Unlike the HM cell, the MM cell forms well-defined ionic percolating pathways and shows excellent structural stability. Consequently, the MM cell exhibits improved capacity retention during 1000 cycles and stable cyclability even under the harsh condition of 7 wt% SE. Finite element analysis theoretically demonstrates that uniform electrode and electrolyte currents are responsible for the improved performances including increased cathode utilization efficiency and reduced overpotentials. This study reveals the importance of composite design and uniform SE distribution in developing high-performance ASSBs at a practical cell level.

In situ DRIFTS analysis of the evolution of surface species over Li6PS5Cl solid state electrolyte during moisture-induced degradation and during heat treatment

Sulfide SSEs (solid-state electrolytes) with high ionic conductivity are attractive for developing high-safety all-solid-state batteries (ASSBs). However, the poor chemical stability of sulfide SSEs toward moisture is a significant problem. Though the decomposition products when exposed to moisture and a possible property recovery by heat treatment are reported, the evolution of surface species in related to moisture exposure and to heat treatment is not clearly identified. This study applies in situ DRIFTS (diffuse reflectance infrared Fourier-transformed spectroscopy) analysis to examine the evolution of the surface species over pristine Li6PS5Cl (LPSC), during moisture exposure, and during heat treatment, complementary with tools like XRD, Raman, etc. The observed surface impurities over pristine LPSC include LiCl·H2O, LiOH·H2O, S3P-SH, PS4-xOx, SOx and carbonate species. Moisture exposure leads to increasing accumulation of these species over LPSC and evolving hydrogen sulfide. A stepwise heat treatment up to 480 °C illustrates the sequential removal of hydrated water, the decomposition of carbonate, LiOH, and PS4-xOx, leaving species like LiCl, Li2O, and PO4 on the surface. The EIS results shows a gradual increase in the ionic conductivity of LPSC with increasing heating temperature, mainly owing to the decreasing surface layer impedance. This strongly suggests that the surface species govern the properties of LPSC. When using the pristine LPSC after heat treatment at 480 °C, the Li||pristine LPSCHT||Li symmetric cell demonstrates a decreased polarization and a much-enhanced cycle stability comparing to the Li||pristine LPSC||Li symmetric cell.

Atomic Origin of Chemomechanical Failure of Layered Cathodes in All-Solid-State Batteries.

The ever-increasing demand for safety has thrust all-solid-state batteries (ASSBs) into the forefront of next-generation energy storage technologies. However, the atomic mechanisms underlying the failure of layered cathodes in ASSBs, as opposed to their counterparts in liquid electrolyte-based lithium-ion batteries (LIBs), have remained elusive. Here, leveraging artificial intelligence-enhanced super-resolution electron microscopy, we unravel the atomic origins dictating the chemomechanical degradation of technologically crucial high-Ni layered oxide cathodes in ASSBs. We reveal that the coupling of surface frustration and interlayer-shear-induced phase transformation exacerbates the chemomechanical breakdown of layered cathodes. Surface frustration, a phenomenon previously unobserved in liquid electrolyte-based LIBs, emerges through electrochemical processes involving surface nanocrystallization coupled with rock salt transformation. Simultaneously, delithiation-induced interlayer shear yields the formation of chunky O1 phases and intricate interfaces/transition motifs, distinct from scenarios observed in liquid electrolyte-based LIBs. Bridging the knowledge gap between the failure mechanisms of layered cathodes in solid-state electrolytes and conventional liquid electrolytes, our study provides unprecedented atomic-scale insights into the degradation pathways of layered cathodes in ASSBs.

Large-Scale Fabrication of Stable Silicon Anode in Air for Sulfide Solid State Batteries via Ionic-Electronic Dual Conductive Binder.

The construction of a continuous ionic/electronic pathway is critical for Si-based sulfide all-solid-state batteries (ASSBs) with the advantages of high-energy density and high-cycle stability. However, a significant impediment arises from the parasitic reaction occurring between the ionic sulfide solid-state electrolyte and electronic carbon additive, posing a formidable challenge. Additionally, the fabrication of electrodes necessitates stringent operational conditions, further limiting practical applicability. Herein, an ionic-electronic dual conductive binder for the fabrication of robust silicon anode under ambient air conditions in the absence of high-cost and air-sensitive sulfide solid-state electrolyte for ASSBs is reported. This binder incorporates in situ reduced silver nanoparticles into a high-strength polymer rich in ether bonds, establishing a conductive pathway for lithium ions and electrons. With the binder-composited Si anode, the half-cell exhibits a remarkable capacity of 1906.9mAhg-1 and stable cycling for 500 cycles at a current density of 2C (4.4mAcm-2) under a low stack pressure of 5MPa. The full cell using Ni0.9Co0.075Mn0.025O2 (NCM90) exhibits a remark cycling stability within 2000 cycles at 5C (8mAcm-2). This work presents an inspired design of functional binders for large-scale manufacture and mild operation in a low-cost way for Si anodes in ASSBs.