Block copolymer electrolytes synthesized by atom transfer radical polymerization for solid-state, thin-film lithium batteries

Block copolymer electrolytes of poly[(oxyethylene)(9) methacrylate]-b-poly(butyl methacrylate) (POEM-b-PBMA) (60:40 by mass) synthesized for the first time by atom transfer radical polymerization (ATRP) exhibited mechanical and electrical properties indistinguishable from those of materials made by the more difficult anionic polymerization method. ATRP offers distinct processing advantages as it is easily scalable and almost solvent-free. Solid-state, thin-film batteries comprised of a metallic lithium anode, a binder-free, additive-free, fully dense vanadium oxide cathode, and an electrolyte of ATRP-synthesized POEM-b-PBMA (60:40) doped with LiCF3SO3 demonstrate resistance to capacity fade during extended cycling at a discharge rate of C/2, and perform comparably to otherwise identical batteries operated with the liquid electrolyte 1 M LiPF6 in ethylene carbonate: dimethyl carbonate (1:1 by mass). (C) 2002 The Electrochemical Society.