Ionic Liquid-Supported Interpenetrating Polymer Network Flexible Solid Electrolytes for Lithium-Ion Batteries

In this report, we have prepared the imidazolium-based ionic liquid-incorporated interpenetrating polymer network (IPN) electrolyte membrane containing cellulose triacetate with polyethylene glycol dimethyl acrylate and polyethylene oxide by the UV-induced polymerization method. A facile IPN electrolyte membrane appears to be homogeneous in nature with high mechanical strength, excellent thermal stability, and exhibits optimum ionic conductivity of the order of 2.84 × 10–3 S cm–1. The oxidative stability of the IPN electrolyte membrane is observed up to 5.2 V at room temperature, which is attributed to immobilized ion networks provided by the imidazolium ionic liquid. The IPN electrolyte membrane is galvanostatically cycled having battery configuration Li/IPN EM/LiFePO4, which shows the first discharge capacity of 110 mA h g–1 at 0.05 C with 93.65% Coulombic efficiency at room temperature. The cell shows discharge capacities of about 85, 82, and 76 mA h g–1 at 0.1, 0.2, and 1 C rates, respectively. The ionic liquid-incorporated IPN electrolyte membrane provides a promising system for stabilizing lithium electrodeposition and fabricating high-performance lithium-ion batteries. Finally, IPN electrolyte membranes could be a potential electrolytes for next-generation high-power and safer solid-state battery technology.