Characterization of cathode degradation and development of a coupled electrochemical-aging model for sulfide-based all-solid-state batteries

Abstract

With the rapid advancement of the electric vehicle industry, traditional lithium-ion batteries with organic liquid electrolytes are increasingly falling short of meeting the demanding standards for energy density and safety. All-solid-state batteries, characterized by their high safety and energy density, are considered the next generation of battery technologies. Among these, sulfide solid-state electrolytes have garnered significant attention due to their high ionic conductivity and excellent processability. However, the aging mechanisms of sulfide-based all-solid-state batteries remain inadequately studied, and the development of aging models for these systems is still in its early stages. This paper primarily investigates the aging mechanisms of the cathode of a sulfide-based all-solid-state battery through various characterization techniques and establishes a coupled electrochemical-aging model correspondingly. Additionally, it emphasizes the often-overlooked role of sulfide electrolyte cracking in the composite cathode as a contributor to the loss of active material. The proposed model demonstrates high accuracy in estimating the state of health of the battery during cyclic aging, offering a new approach to the aging modeling of all-solid-state batteries.