화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.152, No.1, A1-A5, 2005
Rubbery graft copolymer electrolytes for solid-state, thin-film lithium batteries
Graft copolymer electrolytes (GCEs) of poly[(oxyethylene)(9) methacrylate]-g-poly(dimethyl siloxane) (POEM-g-PDMS) (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 similar to25 nm. Over the temperature range 290 < T < 360 K, the electrical conductivities of the lithium triflate-doped POEM-g-PDMS, 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 similar to0.2 mum thick vanadium oxide cathode, and an electrolyte of POEM-g-PDMS doped with LiCF3SO3 proved resistant to capacity fade during extended cycling at room temperature (>200 cycles) at a discharge rate of 2/3 C and could be cycled (charged and discharged) at subambient temperature (0degreesC). (C) 2004 The Electrochemical Society.