Novel poly(methyl methacrylate)-based semi-interpenetrating polyelectrolyte gels for rechargeable lithium batteries

Novel semi-interpenetrating polymer gel electrolytes designed for use in rechargeable lithium polymer batteries are synthesised from methyl methacrylate and the lithium salt of 2-acrylamido-2-methylpropanesulfonic acid (LiAMPS). The gels are made by first synthesising linear chains of poly(LiAMPS) by free radical polymerisation of LiAMPS dissolved in dimethyl acetamide (DMA) or DMA/ethylene carbonate mixtures, then co-polymerisation of methyl methacrylate and a cross-linking monomer (tetraethyleneglycol diacrylate) to form the semi-interpenetrating network. The electrical conductivity of the gels is determined as a function of LiAMPS and methyl methacrylate (MMA) concentrations, cross-link density, and solvent composition. The conductivity (σ) is found to be in the range 0.2 ≤ σ ≤ 0.8 mS cm−1 at ambient temperature (20 ± 1 °C).