An Air‐Stable and Li‐Metal‐Compatible Glass‐Ceramic Electrolyte enabling High‐Performance All‐Solid‐State Li Metal Batteries

Abstract

All-solid-state lithium metal batteries (ASSLMBs) have been regarded as ideal energy storage devices because of their potential to maximize energy density and improve safety. [1-3] As a key part of ASS-LMBs, the development of solid-state electrolytes (SSEs) has drawn increasing attention. [4,5] Among the various types of SSEs, the inorganic glass-ceramic SSE is one of the most promising categories. [6,7] Apart from the advantages of high ionic conductivity and superior mechanical properties in comparison to organic polymer-based SSEs, the glass-ceramic SSEs also show minimal grain boundary resistance and good contact with electrode materials compared to other inorganic ceramic SSEs. [8,9] Sulfide-based glass-ceramic SSEs have received great attention due to their relatively low glass transition temperature (T g , lower than 300 °C). [6,10] The metastable Li-ion conductors (e.g., β-Li 3 PS 4 and Li 7 P 3 S 11) can be precipitated from glass precursors and stabilized in a glass The development of all-solid-state Li metal batteries (ASSLMBs) has attracted significant attention due to their potential to maximize energy density and improved safety compared to the conventional liquid-electrolyte-based Li-ion batteries. However, it is very challenging to fabricate an ideal solid-state electrolyte (SSE) that simultaneously possesses high ionic conductivity, excellent air-stability, and good Li metal compatibility. Herein, a new glassceramic Li 3.2 P 0.8 Sn 0.2 S 4 (gc-Li 3.2 P 0.8 Sn 0.2 S 4) SSE is synthesized to satisfy the aforementioned requirements, enabling high-performance ASSLMBs at room temperature (RT). Compared with the conventional Li 3 PS 4 glass-ceramics, the present gc-Li 3.2 P 0.8 Sn 0.2 S 4 SSE with 12% amorphous content has an enlarged unit cell and a high Li + ion concentration, which leads to 6.2-times higher ionic conductivity (1.21 × 10 −3 S cm −1 at RT) after a simple cold sintering process. The (P/Sn)S 4 tetrahedron inside the gc-Li 3.2 P 0.8 Sn 0.2 S 4 SSE is verified to show a strong resistance toward reaction with H 2 O in 5%-humidity air, demonstrating excellent air-stability. Moreover, the gc-Li 3.2 P 0.8 Sn 0.2 S 4 SSE triggers the formation of Li-Sn alloys at the Li/SSE interface, serving as an essential component to stabilize the interface and deliver good electrochemical performance in both symmetric and full cells. The discovery of this gc-Li 3.2 P 0.8 Sn 0.2 S 4 superionic conductor enriches the choice of advanced SSEs and accelerates the commercialization of ASSLMBs.

Ultrafast Synthesis of I‐Rich Lithium Argyrodite Glass–Ceramic Electrolyte with High Ionic Conductivity

“…The annealed Li 6 PS 5 I shows strong and high-contrast peaks, indicating that post-annealing can synthesize pure argyrodite phase. While for the ball-milled samples, broadened peaks as well as halo backgrounds can be observed, which is very similar to the reported glass-ceramic Li 3 PS 4 and Li 7 P 3 S 11 electrolytes, [39][40][41] suggesting that the electrolytes prepared by UEMA method have partially crystallized small grains within amorphous matrix, named as glass-ceramic argyrodites. According to the Scherrer equation, [42] the mean crystallite size of the LPSI 1+x -gc is ≈15 nm.…”

Energy Storage Materials for Solid‐State Batteries: Design by Mechanochemistry

“…in a Li 3.2 P 0.8 Sn 0.2 S 4 glass–ceramic. [ 161 ] The usage of mechanochemical synthesis again demonstrates how the kinetic energy transfer enables the formation of metastable compounds and local structures that are not accessible via classic solid‐state routes.…”

Air‐stable inorganic solid‐state electrolytes for high energy density lithium batteries: Challenges, strategies, and prospects

“…Then, the optimum As-doped Li 3.833 Sn 0.833 As 0.166 S 4 possessed a high conductivity of 1.39 Â 10 À3 S cm À1 at 25 C. 57 In addition, Sn 4+ -doped glass-ceramic Li 3.2 P 0.8 Sn 0.2 S 4 showed strong resistance to H 2 O in 5% humidity air, benefiting from the (P/Sn)S 4 tetrahedron structure. 98 Sun et al 99 reported the strong Sn S bond in Li 6.2 P 0.8 Sn 0.2 S 5 I stabilized crystal structure and improved air stability when exposed to air. Liang et al reported that Li 10 Ge(P 0.025 Sb 0.075 )S 12 exhibited a good air stability of sulfide SSEs due to the softer acid Sb 5+ through HSAB theory.…”