Preparation and performance of polymer/graphene composite solid electrolyte film

The polymer solid electrolyte has a simple preparation method, good film-forming performance, and good electrode-electrolyte interface contact. However, the low room temperature ionic conductivity, poor electrochemical stability, and the inability to match the cathode material with a wide voltage window limit the large-scale commercial application of polymer solid electrolytes; graphene has excellent mechanical, mechanical properties, photoelectric thermal properties and a large specific surface area, high ion conductivity and electron migration number, so it has strong electrical conductivity. In this paper, a typical polymer solid electrolyte polyethylene oxide (PEO) and graphene composite are selected to further enhance the electrochemical performance of the composite material. Experiments have found that the polymer/graphene composite solid electrolyte membrane with graphene added does not decompose significantly before 5 V, which clarifies that it has good electrochemical stability. And the first charge-discharge specific capacity of the composite solid electrolyte membrane is higher than that of the single polymer solid electrolyte membrane. Neither the diffraction peak nor the reduction peak shifted after 5 cycles, and the cycle life was still 99.449% after 100 cycles, indicating that it has good cycle stability. Therefore, the application of polymer/graphene composite solid electrolyte membranes in all-solid-state lithium batteries is feasible.