PEO based Block Copolymer as Solid State Lithium Battery Electrolyte

Abstract

We report the use of a conductive electrolyte matrix containing a secondary source of lithium templated by the microphase separation of a block copolymer. The desired polymer matrix is synthesized by hydrolyzing a block copolymer of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA), to generate a lithium salt of acrylic acid in the minority block (PMAALi), resulting in a block copolymer with a random copolymer as its second block, PEO-b-(PMMA-ran-PMAALi). The electrolyte composition was optimized at (ethylene oxide : lithium bis(oxalato)borate = 3:1) and exhibited nearly an order of magnitude higher conductivity than PEO of similar molecular weight and salt composition.