Electrical properties of fluorinated gel electrolytes using high ionic conducting solution and its application to secondary battery

Abstract

Lithium ionic electrolytes of fluorinated gel materials have been found to show high ionic conductivity. We proposed to apply this gel electrolyte to a secondary battery. Non-crosslinking fluorinated gel materials were prepared by reacting fluoroalkanoyl peroxides with 2-acrylamid-2-methyl-propanesulfonic acid (AMPS) oligomer containing fluoroalkylated end-capped units {[R F(AMPS) q] p}. Four kinds of lithium salts were used for ionic electrolyte of fluorinated gel materials. The ionic conductivity of gel electrolytes depended on the chain length of R F, the lithium salt material and its concentration. The maximum conductivity was 2.1×10 −2 S/cm when used by the ionic solution, the lithium salt with LiN(CF 3SO 2) 2 and the concentration of 5.7 mmol/g, respectively. We also measured the charge and discharge characteristics of secondary batteries that were fabricated by a carbon negative electrode, fluorinated gel electrolyte and a positive electrode of LiCoO 2.