Challenges and Developments of High Energy Density Anode Materials in Sulfide‐Based Solid‐State Batteries

Abstract

All-solid-state batteries (ASSBs) are considered the most promising next-generation energy storage device owing to their high safety. The sulfide solid electrolytes (SEs) possess high ionic conductivity (10 À 4 -10 À 2 S cm À 1 ) at room temperature, nonflammable properties, and moderate modulus, all of which are crucial requirements for the scalable application of highperformance ASSBs. However, achieving a high energy density of > 300 Wh kg À 1 appears to be a significant hurdle in current ASSBs. Research on high-energy-density anode materials is of great importance for enhancing the overall energy density in ASSBs. However, relatively few review articles have focused on the overall development profile of representative anode materials in sulfide SEs. Here, we start by underlining the importance of the multi-physical properties of sulfide SEs, including ionic conductivity, chemical properties, and mechanical properties. Furthermore, the potential failure mechanisms of sulfide SEs with Li anodes and corresponding improvement strategies are systematically discussed. Finally, we summarize recent notable works of anode materials in sulfide-based ASSBs, aiming to provide important guidance for fulfilling a real leap of high energy density anode materials in sulfide ASSBs.

Dendrite growth and inhibition in all-solid-state lithium metal batteries: in situ optical observation

“…All-solid-state lithium metal batteries based on inorganic solidstate electrolytes (SSEs) could potentially provide higher energy density and better integration capability, which is desirable for future electrical vehicles and other applications. [1][2][3][4][5][6] Suldebased solid electrolyte Li 6 PS 5 Cl (LPSC) has been widely studied due to its high ionic conductivity (over 10 −3 S cm −1 ), simple synthesis process, excellent mechanical properties and negligible grain boundary impedance. [7][8][9][10][11][12][13][14][15] However, all-solidstate lithium metal batteries based on LPSC still face a serious short-circuiting problem.…”

“…[7][8][9][10][11][12][13][14][15] However, all-solidstate lithium metal batteries based on LPSC still face a serious short-circuiting problem. 1,9,[16][17][18][19][20] Dendrite growth in inorganic SSEs has been investigated before, but a clear picture of its growth mechanism is still missing. 17,[21][22][23][24][25] For a polycrystalline SSE sample such as LPSC, there are two possible dendrite growth mechanisms.…”