Ether-containing polycarbonate-based solid polymer electrolytes for Dendrite-Free Lithium metal batteries

Abstract Lithium metal is considered an ideal anode material for next-generation high-energy-density batteries, owing to its high theoretical specific capacity and low reduction potential. However, the uncontrolled growth of Li dendrites during cycling has limited its industrial application. In this work, a poly (allyl diglycol carbonate)-based solid polymer electrolyte (PADC-SPE) combining the advantages of polyether and polycarbonate-based solid electrolytes was prepared by in-situ polymerization. According to space charge theory, the uniform free movement of lithium ions in the electrolyte can prevent electric field generation at the anode surface, facilitating the safe and ordered deposition of lithium ions. Therefore, PADC-SPE exhibited excellent ionic conductivity (1.96 × 10−5 S cm−1), a wide electrochemical window (5.5 V), and a high Li-ion transference number (t+ = 0.67) at room temperature. Surprisingly, a smooth surface was observed for the Li anode of Li/Li cells after constant-current charge–discharge cycling for 800 h. A LiFePO4/PADC–SPE/Li battery showed excellent high-temperature (60 °C) cycling performance, with a discharge specific capacity reaching 145.1 mAh g−1 at 0.3C and retaining 99.2% of its first-cycle value after 110 cycles. Based on this excellent performance, PADC-SPE represents a promising system for developing safe and high-performance Li metal batteries.