A Bilayer Electrolyte Design to Enable High-Areal-Capacity Composite Cathodes in Polymer Electrolytes Based Solid-State Lithium Metal Batteries
Ritu Sahore, Guang Yang, X. Chelsea Chen, Wan‐Yu Tsai, Jianlin Li, Nancy J. Dudney, Andrew S. Westover
Abstract
High-areal-capacity cathodes are needed for energy-dense solid-state batteries. Here, we demonstrate a bilayer polymer electrolyte design for cycling 3–6 mAh/cm2 NMC811 composite cathodes. The bilayer electrolyte comprises a cross-linked poly(ethylene oxide) (PEO)-based electrolyte layer and a linear-PEO-based electrolyte layer. The former provides dendritic resistance, and the latter provides a seamless interface with the cathode during cycling. Using a single layer of either membrane led to severe shorting or extremely low Coulombic efficiency (CE) in the first cycle. The general concept of a rigid dendrites-inhibiting electrolyte facing Li anode and a softer, cathode-integrated electrolyte that ensures contact with the cathodes during cycling may present a pattern for enabling high-energy-density cathodes.