Super Long‐Cycling All‐Solid‐State Battery with Thin Li₆PS₅Cl‐Based Electrolyte

Abstract

high interfacial impedance between SSEs and electrodes, and relatively high fabrication cost, which impede their applications. SSEs with high ionic conductivity, wide electrochemical window and low interfacial impedance are critical in developing ASSBs with high specific energy and power density. [2,3] Currently, among various SSEs, sulfide SSEs have a Li-ion conduction capability comparable to that of organic liquid electrolytes (≈10 -2 S cm -1 at room temperature). [4][5][6][7][8][9][10] Various sulfide materials with a high Li-ion conductivity of 10 -3 -10 -2 S cm -1 at room temperature, such as Li 10 GeP 2 S 12 (LGPS), [5] Li 10 SnP 2 S 12 , [6] and Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 , [7] have been investigated. Among them, a family of sulfide SSEs, lithium argyrodites Li 6 PS 5 X (X = Cl, Br), [8] are attracting more attention due to high Li-ion conductivity (e.g., Li 5.3 PS 4.3 ClBr 0.7 : 2.4 × 10 -2 S cm -1 ; [9] Li 6 PS 5 Cl (denoted as LPSCl): 3.15 × 10 -3 S cm -1 [10] ) and relatively good electrochemical compatibility. The ASSB cells using argyrodites have demonstrated good cycling and rate performance. For example, recently, a sandwiched SSE separator of LPSCl-LGPS-LPSCl has been designed to prevent the growth of Li dendrites and thus enable superior cycling performance of ASSB cells; [11] and LPSCl SSE has also been matched with the silicon anode, capable of operating with high current densities and achieving a long cycle. [12] One drawback of pressed sulfide SSE separator layers is that micro-cracks easily appear and expands during Li plating/stripping in sulfide electrolytes due to the rigidness of sulfide powders, leading to short circuit in ASSB cells. [13] Thus a thicker sulfide SSE layer (e.g., ≈0.5-1.2 mm) via pressing sulfide powder was usually used in laboratory-type cells to guarantee the long-term cycling performance of the ASSBs, [13a,b,14] but this way reduces the cell-level energy density and is detrimental to scalable fabrication. Thus, it is desired to prepare sulfide SSE membranes with a small thickness and compact structure for advanced ASSBs.To obtain a thin, free-standing sulfide SSE membrane, a soft polymeric component is often used. Recently, much progress in sulfide-polymer composite solid electrolytes (CSEs) has been made. [15][16][17][18] Among them, Luo et al. prepared a 65 µm-thick bendable sulfide SSE using LPSCl and poly(ethylene oxide) (PEO), [16] and their ASSB cell of LiNi 0.7 Co 0.2 Mn 0.1 O 2 (LiNi x Co y Mn 1-x-y O 2 , denoted as NCM)||CSE||lithium-indium All-solid-state batteries (ASSBs) using sulfide electrolytes have attracted everincreasing interest due to high ionic conductivity of the sulfides. Nevertheless, a thin, strong solid-state sulfide electrolyte membrane maintaining high ionic conductivity is highly desired for ASSBs. Here, a thin, flexible composite solid electrolyte membrane composed of argyrodite sulfide Li 6 PS 5 Cl and a polar poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) framework is prepared via an electrospinning-infil...

A Review of Polymer‐based Solid‐State Electrolytes for Lithium‐Metal Batteries: Structure, Kinetic, Interface Stability, and Application

“…Nan and his colleague constructed a three-dimensional poly(vinylidene fluorideÀ cotrifluoroethylene) P(VDFÀ TrFE) network composed of argyrodite Li 6 PS 5 Cl (LPSCl) by electrospinning-infiltration-hot-pressing method. [70] Interaction of polar P(VDFÀ TrFE) and LPSCl not only generates high ionic conductivities, but also produce good mechanical and reach the thickness of 30-40 μm.…”

A review of all-solid-state electrolytes for lithium batteries: high-voltage cathode materials, solid-state electrolytes and electrode–electrolyte interfaces

“…There are three types of ternary high nickel cathode materials: LiNi 0.5 Mn 0.3-Co 0.2 O 2 (NCM 523 ), 76,77,[86][87][88] LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NCM 622 ) 89-94 and LiNi 0.8 Mn 0.8 Co 0.1 O 2 (NCM 811 ). [95][96][97][98][99][100] In these three types of ternary cathode materials, Ni has two valence states, namely +2 and +3, while Co is in its +3 state and Mn still maintains its +4 state, which is used to keep the material structure stable. When the charging voltage is lower than 4.4 V, Ni 2+/3+ is oxidized to Ni 4+ in the reaction.…”

Phosphorus‐Based Materials for High‐Performance Alkaline Metal Ion Batteries: Progress and Prospect

“…Zhang et al have revealed the evolution of the space charge layer of NCM811/ Li 6 PS 5 Cl /Li batteries by in situ electrochemical impedance spectroscopy and Raman spectroscopy. [173] In the early stage of the cycle, the space charge layer is the main factor affecting the deterioration of the battery interface. The migration and redistribution of Li + at the interface caused by the space charge layer (Li + transfers from the sulfide side to the oxide side) leads to the interfacial change of PS bond state in the sulfide electrolyte Li 6 PS 5 Cl.…”

“…The migration and redistribution of Li + at the interface caused by the space charge layer (Li + transfers from the sulfide side to the oxide side) leads to the interfacial change of PS bond state in the sulfide electrolyte Li 6 PS 5 Cl. [173] The increase in battery cycles, interfacial reactions, mechanical failures, and dendrite growth lead to the deterioration of the interface, resulting in the degradation of battery performance. This in-depth interfacial research work provides an important theoretical reference for optimizing all-solid-state batteries.…”