Cathode/gel polymer electrolyte integration design based on continuous composition and preparation technique for high performance lithium ion batteries

Abstract

Gel polymer electrolytes (GPEs) combine the high ionic conductivity of liquid electrolytes and good safety assurance of solid electrolytes. However, the poor interfacial contact between electrode materials and electrolyte is still a big obstacle to the high performance of solid-state batteries. Herein, an integrated cathode/GPE based on continuous composition and preparation technic is obtained by simple UV curing. The improved interfacial contact between cathode and GPE helps to facilitate the fast ions transfer at the interface. Compared with cells assembled with separated cathode and GPE, the cells with integrated cathode-GPE showed much lower interfacial impedance, lower potential polarization and more stable cycling property. This work provided a low-cost natural material gelatin and a simple UV irradiation method to prepare an integrated cathode and gel polymer electrolyte for solid-state lithium batteries. The capacity retention of the cells assembled from integrated structure was 91.4% which was much higher than that of the non-integrated cells (80.9%) after 200 cycles.