A physical organogel electrolyte:characterized by in situ thermo-irreversible gelation and single-ion-predominent conduction

Abstract

Electrolytes are characterized by their ionic conductivity (sigma(i)). It is desirable that overall si results from the dominant contribution of the ions of interest (e. g. Li+ in lithium ion batteries or LIB). However, high values of cationic transference number (t(+)) achieved by solid or gel electrolytes have resulted in low sigma(i) leading to inferior cell performances. Here we present an organogel polymer electrolyte characterized by a high liquid-electrolyte-level sigma(i) (similar to 10(1) mS cm(-1)) with high t(+) of Li+ (>0.8) for LIB. A conventional liquid electrolyte in presence of a cyano resin was physically and irreversibly gelated at 60 degrees C without any initiators and crosslinkers, showing the behavior of lower critical solution temperature. During gelation, sigma(i) of the electrolyte followed a typical Arrhenius-type temperature dependency, even if its viscosity increased dramatically with temperature. Based on the Li+-driven ion conduction, LIB using the organogel electrolyte delivered significantly enhanced cyclability and thermal stability.