Abstract: The present invention discloses non-aqueous electrolytes for lithium ion batteries. Said electrolytes comprise of lithium salts and a non-aqueous organic solvent. The non-aqueous organic solvent comprises of compounds having the formate derivative or formamide derivative. The chemical formulas for these compounds are HCOOR1 and HCONR2R3, where R1, R2, R3 are alkyls having 1 to 4 carbon atoms. The weight percentage of the compounds having the formate derivative or formamide derivative is between 5 wt % and 70 wt % of the total weight of the non-aqueous organic solvent. Lithium ion batteries using said electrolytes exhibit improved discharge properties at low temperatures. These batteries are especially suitable for use as power batteries with large capacities.