A flexible solvent-free polymer electrolyte based on methacrylic monomer fabricated by UV-curing for lithium-ion batteries

Safety issues including flames, leakage, and explosions of lithium-ion batteries caused by liquid organic electrolyte have been driving individuals to study safer electrolytes. In this work, we fabricated solvent-free polymer electrolytes (SPEs) by ultraviolet curing (UV-curing) technology for lithium-ion batteries. This kind of electrolyte was prepared by mixing poly (ethylene glycol) dimethacrylate (PEGDMA) and LiFSI with a different weight ratio. We employed LiFSI as a lithium salt because its high room temperature ionic conductivity and low viscosity. Furthermore, a methacrylic polymer network (PEGDMA) with compliant hydrocarbon chains was introduced as a new polymer matrix, not only owing to it provides a flexible and compliant mechanical framework but also due to its strong lithium salts solvation ability. UV-curing reaction of electrolytes was confirmed by FT-IR and gel content calculation. In addition, thermal stability and ionic conductivity also have been measured as detailed properties to prove that these solvent-free electrolytes can offer some promising performances and greatly beneficial for various lithium-ion battery devices.