Recent advances in solving Li2CO3 problems in garnet-based solid-state battery: A systematic review (2020–2023)

Garnet solid electrolytes are one of the most promising electrolytes for solid-state batteries. However, Li2CO3 is a critical issue that hinders the practical application of garnet-based solid-state lithium-ion batteries. There are two sources of Li2CO3 contamination. The main one is the aging of garnet electrolytes in the atmosphere. Garnet electrolytes can react with H2O and CO2 in the air to form Li2CO3, which reduces ion conductivity, increases electrode/garnet electrolyte interface resistance, and deteriorates the electrochemical performance of the battery. Various strategies, such as elemental doping, grain boundary manipulation, and interface engineering, have been suggested to address these issues. The other is the passivation layer (Li2CO3, Li3N, LiOH, Li2O) formed on the surface of the lithium foil after long-term storage, which is ignored by most researchers. To better understand the current strategies and future trends to address the Li2CO3 problem, this perspective provides a systematic review of journals published in this field from 2020–2023.