A high-performance polymer composite electrolyte embedded with ionic liquid for all solid lithium based batteries operating at ambient temperature

A novel polymer composite electrolyte for lithium-based battery operating at room temperature was introduced. The proposed polymer composite electrolyte consisted of electrolyte using a 3-D cross-linked polymer matrix, which is synthesized with polyethylene glycol (PEG) and 3-glycidoxypropyltrimethoxysilane (GPTMS), and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMITFSI) as a Li-ion transport medium. The proposed polymer composite electrolyte shows a high ionic conductivity of 35 × 10⁻² mS cm⁻¹ and high decomposition temperature of 250 °C with a 3-D cross-linked polymer matrix. The EMITFSI mass ratio is 1:0.7 at room temperature. In addition, when polymer composite electrolyte is applied to the solid battery consisting of Li metal as an anode and LiFePO₄ as a cathode, it can be operated at room temperature with a high specific capacity of 75.8 mAh/g at 0.1C rate. Furthermore, the battery with a structure of Li/polymer composite electrolyte/LiFePO₄ also has excellent capacity retention.