Polymer electrolytes based on hyperbranched polymers

A hyperbranched poly[bis(hexaethylene glycol)benzoate] with terminal acetyl groups was prepared, and ionic conductivity, thermal property, and electro chemical stability of the polymer electrolyte with LiN(CF3SO2)(2) were inve stigated. Ionic conductivity of the polymer electrolyte exhibited a maximum value of 9 x 10(-5) S/cm at a [LiN(CF3SO2)(2)]/[repeat unit] ratio of 0.6 (corresponding to a Li/O ratio of 0.04) and 80 degreesC. The effect of a hy perbranched polymer, a poly[bis(triethylene glycol)benzoate] with terminal acetyl groups (poly-Ac1b), as an additive on ionic conductivity of a linear poly(ethylene oxide) (PEO)/LiN(CF3SO2)(2) electrolyte was also investigate d. Addition of 10 wt.% poly-Ac1b improved ionic conductivity and also ion t ransference number in the polymer electrolyte. (C) 2001 Elsevier Science B. V. All rights reserved.