Formation of an organized structure under organic solvent in Li-ion battery to sulfonated polyimide thin films and application to an artificial cathode-electrolyte interphase

Abstract

We investigated the molecular assembly structures and Li-ion conductivity of lyotropic liquid crystalline polymer electrolytes by adding organic solvents commonly used in Li-ion batteries. It was found that adding a mixture of ethylene carbonate and dimethyl carbonate resulted in forming a highly crystalline organized structure and improved Li-ion conductivity due to the solvation of Li ions. Furthermore, we demonstrated that coating sulfonated polyimide thin films to the cathode of a Li-ion battery as an artificial cathode-electrolyte interface (CEI) was effective in improving capacity retention at high-rate discharge compared to the uncoated case.