New materials derived from poly(4-hydroxystyrene) as lithium battery cell components

A new class of polyethers has been prepared by the Mitsunobu coupling of po ly(4-vinyl phenol), P4VP, with low molecular weight poly(ethylene glycol)me thyl ether. These comb-like polymers, having ca. 20-30% residual phenols, w ere characterized by IR, DSC, and TGA. Results of thermal analysis on the p olymers suggest thermal stability to at least 300 degreesC and a glass tran sition temperature in the range -30 to -40 degreesC. Complexes with LiPF6 g ave conductivities of ca. 1 x 10(-5) S/cm at room temperature. The polymers were blended with plasticized poly(vinylidene fluoride) (PVDF) to prepare porous films and subsequently infiltrated with lithium salts and ethylene a nd ethyl methyl carbonate. Ionic conductivities of these hybrid films were measured from -20 degreesC to 40 degreesC. Conductivities as high as 2.4 x 10(-3) S/cm are observed at room temperature. The electrochemical stability of hybrid materials was studied by cyclic voltammetry.