Rubbery Graft Copolymer Electrolytes for Solid-State, Thin-Film Lithium Batteries

Abstract

Graft copolymer electrolytes (GCEs) of (70:30) have been synthesized by simple free radical polymerization using a macromonomer route. Differential scanning calorimetry, transmission electron microscopy, and small angle neutron scattering confirmed the material to be microphase-separated with a domain periodicity of Over the temperature range the electrical conductivities of the lithium triflate-doped which exhibited solid-like mechanical behavior, were nearly identical to those of the liquid POEM homopolymer. Thermal and electrochemical stability studies showed the electrolyte to be stable over a wide temperature range and voltage window. Solid-state, thin-film batteries comprised of a metallic lithium anode, a thick vanadium oxide cathode, and an electrolyte of doped with proved resistant to capacity fade during extended cycling at room temperature at a discharge rate of 2/3 C and could be cycled (charged and discharged) at subambient temperature (0°C). © 2004 The Electrochemical Society. All rights reserved.