Solid-State Graft Polymer Electrolytes with Conductive Backbones and Side Chains for Lithium Batteries

Graft polymers have been widely investigated as solid polymer electrolytes (SPEs) in the past decades. However, the presence of insulating backbones in the conventional graft polymers damps the overall Li+ conductivity and transport number (tLi+). Herein, a series of polycarbonates (PCs) possessing ethylene oxide (EO) side chains were designed and synthesized through ring-opening polymerization (ROP), and their ionic conductivities were evaluated as SPEs with LiTFSI. The synergy of conductive backbones and side chains gives a high tLi+ value of 0.67 while having an ionic conductivity of 2 × 10–5 S cm–1 at 30 °C. This work provides new insights into the development of high-performance SPEs by combining different conductive polymers.