Digital‐twin‐driven structural and electrochemical analysis of Li+ single‐ion conducting polymer electrolyte for all‐solid‐state batteries

Abstract

AbstractThe electrode structure is a crucial factor for all‐solid‐state batteries (ASSBs) since it affects the electronic and ionic transport properties and determines the electrochemical performance. In terms of electrode structure design, a single‐ion conducting solid polymer electrolyte (SIC‐SPE) is an attractive solid electrolyte (SE) for the composite electrode among various SEs. Although the ionic conductivity of SIC‐SPE is lower than other inorganic SEs, the SIC‐SPE has a relatively lower density and can form an intimate contact between the SE and active materials (AM), resulting in an excellent electrode structure. The electrochemical performance of the cell with SIC‐SPE was comparable with the cell with Li6PS5Cl (LPSCl), which has 10 times higher intrinsic ionic conductivity than SIC‐SPE (SIC‐SPE: 0.2 × 10−3 S cm−1, LPSCl: 2.2 = 10−3 S cm−1 at 25°C). 3D digital‐twin‐driven simulation showed that the electrode with SIC‐SPE has a higher SE volume fraction, a lower tortuosity, and a larger AM/SE contact area than the LPSCl electrode. The favorable structure of the SIC‐SPE electrode leads to lower overpotential than the LPSCl electrode during operation. Our results suggest that the SIC‐SPE is a promising SE for making a good electrode structure in ASSBs.