Ameliorating structural and electrochemical properties of traditional poly-dioxolane electrolytes via integrated design of ultra-stable network for solid-state batteries

Abstract

Poly(1,3-dioxolane) (PDOL)-based solid electrolytes hold great potential for solid-state lithium metal batteries (SLMBs) due to their high ionic conductivity, good lithium metal compatibility, and facile synthesis through in-situ polymerization. However, traditional PDOL electrolyte suffers from inferior structural stability and low Li-ion transference number (tLi+), which has impeded PDOL from authentic commercialization. Here we design and attain an ultrathin crosslinked polymer electrolyte (viz. PTADOL) to significantly upgrade the functional properties of PDOL. The in-situ formed PTADOL has rational O-Li+ coordination for fast Li+ transport, which enhances both ionic conductivity and tLi+. The unique integrated network structure stabilizes the electrode/electrolyte interface, and achieves additional favorable features, including improved oxidative stability, thermal stability, and flame retardancy. Based on the ultra-stable PTADOL polymer electrolyte, the high-voltage LiNi0.8Mn0.1Co0.1O2||Li solid batteries exhibit excellent operation stability with suppressed polymer degradation. This work provides not only a practical approach to the design of highly stable solid polymer electrolytes for SLMBs, but also the deep understanding of enhancement mechanism.