Electrochemically and chemically stable electrolyte–electrode interfaces for lithium iron phosphate all-solid-state batteries with sulfide electrolytes

Abstract

All-solid-state batteries which use inorganic solid materials as electrolytes are the futuristic energy storage technology because of their high energy density and improved safety. One of the significant challenges facing all-solid-state batteries is the poor compatibility between electrolyte and electrode materials at their point of contact, which negatively impacts battery performance. Therefore, it is important to find appropriate interfacial materials that can mediate the electrolyte–electrode reaction while maintaining efficient ionic transportation in all-solid-state batteries. In the past, the mechanism of interaction between the electrolyte and the electrode was explored and a number of potential coating materials for layered NCM and LiCoO₂ cathodes were found. In this paper, employing a similar computational scheme, we extend such coating material screening to LiFePO₄-based all-solid-state batteries with sulfide electrolytes. Harnessing a trove of first-principles data in the Atomly materials database, we comprehensively evaluated and screened the coating compounds based on their thermodynamic stability, (electro)chemical stability, electronic conductance, ionic conductance, etc., and successfully found 41 promising coating compounds out of the 54 005 candidates. This paper offers insightful directives for optimizing the performance of LiFePO₄-based all-solid-state batteries.