Electrochemical behavior of butylene sulfite as novel film-forming electrolyte additive for lithium ion batteries

As a novel organic solvent electrolyte material, sulfites possess high a antioxidation and electrochemical stability. Butylene sulfite with cyclic structure was synthesized. The total energy and the frontier molecular orbital energy of the organic butylene sulfite and propylene carbonate molecules were calculated. The LUMO energy and the total energy of the propylene carbonate molecule were lower than that of the butylene. sulfite molecule. It is clearly indicated that the butylene sulfite molecule can easily accept electrons and bears a high reaction activity. Even in additive amounts (volume fraction 5%) butylene sulfite is suppressing co-intercalation of propylene carbonate(PC) into graphite. The formation of a stable passivating film on the graphite surface was believed to be the reason for the improved cycle performance for lithium ion battery.