Elastomer-based electrolytes for high-energy solid-state lithium metal batteries

Abstract

The use of lithium (Li) metal anodes in solid-state batteries has emerged as the most promising technology for replacing conventional Li-ion batteries. Here, we report a new class of solid-state electrolytes based on an in-situ-polymerized elastomer matrix containing a three-dimensional interconnected plastic crystal phase. The plastic-crystal-embedded elastomer electrolyte (PCEE) exhibits high ionic conductivity (~1.1 mS cm-1), superior mechanical stability, low interfacial resistance, and a high Li-ion transference number. In-situ-formed PCEE on copper foils effectively accommodates volume changes during Li plating/stripping processes with a Coulombic efficiency of 100.0%. We demonstrate the stable operation of PCEE-based Li-LiNi0.83Mn0.06Co0.11O2 batteries at a high voltage of 4.5 V at 20 oC. The introduced elastomer-based electrolyte system presents a powerful strategy for enabling the stable operation of high-energy, solid-state Li metal batteries.