Effects of vinyl carbonate on polymer lithium ion battery

Vinylene carbonate (VC) is an important additive to electrolyte of lithium ion battery, and the effect on the performance of polymer lithium ion battery was studied. It was found that the internal resistance of battery was reduced and the cycle performance and discharge performance at higher and lower temperature was improved after VC was added into organic electrolyte of polymer lithium ion battery. It was demonstrated through cyclic voltammetry that one reversible peak appeared at the voltage region -1.5 - -2.0V and the initial irreversible capacity of battery was reduced after the addition of VC. It was also showed by the results of AC impedance that the addition of VC decreased the resistance of interface, charge transfer reaction and diffusion in solution and made the migration of lithium ion easier. Further more, it increased the density of SEI film, so the performance of battery was improved.