To apply widely the cathode material lithium manganese oxide (LiMn2O4) with spinel structure, temperature characteristics of LiMn2O4 electrode were studied to decrease the expansion extent by applying different additives in the electrolytes. Different addition contents of 1,3-propane sultone (1,3-PS) and propylene carbonate (PC) in the electrolytes were studied. The results showed PC and 1,3-PS could decrease the thickness variation of cells stored at elevated temperature. Lithium bis(oxalate) borate (LiBOB) additive was investigated to improve the storage characteristics at elevated temperature and cycling performance (25°C) of the cell with LiMn2O4 cathode. The results showed that LiBOB improved remarkably the storage characteristics and cycling performance of the cells. And an advanced electrolyte was developed.