Understanding the short-circuiting mechanism of solid-state electrolytes for realizing high performance of an all-solid-state-lithium battery

Abstract

This paper introduces the recent progress in our understanding of the short-circuiting mechanism of inorganic-solid-state electrolytes during charging/discharging of an Li metal anode in a solid-state battery.　Solid-state electrolytes are recognized as a key material, which could pave the path to realizing high-energy-density-secondary batteries.　Cubic-Li₇La₃Zr₂O₁₂ (LLZ) is a strong candidate as a solid-state electrolyte to achieve a highly reversible Li metal anode.　However, a short-circuiting event is inevitable with LLZ.　The mechanism for a softer Li to penetrate a more rigid LLZ remains unelucidated, but it has been understood that tiny voids, which are formed near the Li/LLZ interface during Li stripping, cause an increase in local current density.　This increased local current density eventually exceeds the threshold for short-circuiting to occur.