Interface Issues and Challenges in All‐Solid‐State Batteries: Lithium, Sodium, and Beyond

Abstract

Owing to the promise of high safety and energy density, all‐solid‐state batteries are attracting incremental interest as one of the most promising next‐generation energy storage systems. However, their widespread applications are inhibited by many technical challenges, including low‐conductivity electrolytes, dendrite growth, and poor cycle/rate properties. Particularly, the interfacial dynamics between the solid electrolyte and the electrode is considered as a crucial factor in determining solid‐state battery performance. In recent years, intensive research efforts have been devoted to understanding the interfacial behavior and strategies to overcome these challenges for all‐solid‐state batteries. Here, the interfacial principle and engineering in a variety of solid‐state batteries, including solid‐state lithium/sodium batteries and emerging batteries (lithium–sulfur, lithium–air, etc.), are discussed. Specific attention is paid to interface physics (contact and wettability) and interface chemistry (passivation layer, ionic transport, dendrite growth), as well as the strategies to address the above concerns. The purpose here is to outline the current interface issues and challenges, allowing for target‐oriented research for solid‐state electrochemical energy storage. Current trends and future perspectives in interfacial engineering are also presented.

Material design and structure optimization for rechargeable lithium-sulfur batteries

“…To address these issues, various function layers, such as polymer interlayers, in-situ-formed inorganic coatings, and Li alloys have been successfully used to lower the interface impedance and enhance the compatibility. [243][244][245][246][247] A few SIEs, such as hydrides (LiBH 4 and LiBH 4 -LiCl) 248,249 and sulfides (Li 10 GeP 2 S 12 , Li 10 SnP 2 S 12 and Li 3 PS 4 . ), [250][251][252][253] have been successfully used for all-solid-state Li-S batteries.…”

Progress and Challenges for All‐Solid‐State Sodium Batteries

“…The HT sintering process would introduce unwanted side reactions, however, and elemental inter‐diffusion, thus enlarging the interfacial resistance. [ 156 ]…”

“…[ 169 ] In addition, Na metal has a lower melting point and mechanical modulus, which will contribute to a highly wettable anode interface; therefore, it is a great interest to develop ASSBs. [ 106,156 ] Nevertheless, directly utilizing Na metal may present a safety issue because of its high chemical reactivity. There are still two issues facing sodium metal anode that significantly restrict its practical application.…”

Dendrites in Solid‐State Batteries: Ion Transport Behavior, Advanced Characterization, and Interface Regulation

“…[ 3 ] Nevertheless, the highly electrochemical reactivity of lithium metal and continuous growth of dendrites in commonly used organic and unstable flammable electrolytes are critically challenging for lithium‐metal batteries. [ 4 ] Moreover, the flammable and explosive cases of liquid‐electrolyte LIB triggered by the potential overcharging or short‐circuiting have been widely reported around the world, [ 5–7 ] which is expected to be overcome urgently.…”