Toward Higher Voltage Solid‐State Batteries by Metastability and Kinetic Stability Design
Luhan Ye, William W. Fitzhugh, Eva Gil‐González, Yichao Wang, Yibo Su, Haoqing Su, Tianyu Qiao, Lu Ma, Hua Zhou, Enyuan Hu, Xin Li
Abstract
Abstract The energy density of battery systems is limited largely by the electrochemical window of the electrolyte. Herein, the combined thermodynamic and kinetic effects of mechanically induced metastability are shown to greatly widen the operational voltage window of solid‐state batteries based on ceramic‐sulfide electrolytes. Solid electrolyte voltage stability up to 10 V is achieved with minimal degradation, far beyond the capability of organic liquid electrolytes. Furthermore, combined experiment, ab initio computation, and theoretical modeling identify the nature of mechanically constrained Li 10 GeP 2 S 12 decomposition both within the bulk and at interfaces with cathode materials at very high voltages. Previously unclear kinetic processes are identified that, when properly implemented, can potentially allow solid‐state full cells with remarkably high operational voltages.