Development of novel PMMA-based polyelectrolyte gels containing linear chains of LiAMPS copolymers

Abstract

Charge transport and mechanical properties are coupled with each other in a semi-interpenetrating network gel, in which the ionic polymer chains are intertwined with but not covalently bonded to a network by the cross linked non-ionic polymer poly (methyl methacrylate) (PMMA). In this study, an attempt has been made to synthesize new semi-interpenetrating polymer gel electrolytes with high conductivity as well as strength for use in rechargeable lithium polymer batteries. The gels are synthesized from methyl methacrylate and the copolymers of lithium salt of 2-acrylamido-2-methylpropanesulfonic acid (LiAMPS) with four different monomers; styrene, vinyl acetate, Veova 10 and sodium styrene sulphonate. The gels are made by first synthesizing linear chains of LiAMPS-co-monomers copolymers by free radical polymerization of LiAMPS and each monomer dissolved in dimethylacetamide (DMA), then polymerization of methyl methacrylate and a cross linking monomer (tetraethyleneglycol diacrylate) to form the semi-interpenetrating network. The electrical conductivity of each gel is determined as a function of monomer/LiAMPS ratio. Compared to Poly (LiAMPS) and other copolymers, the gels based on LiAMPS-co-styrene copolymers show a good balance between conductivity and strength properties.