US Patent 7931987 Lithium-ion battery

A lithium-ion battery includes a positive electrode comprising a current collector and a first active material comprising LiCoO2 and a negative electrode comprising a current collector, a second active material, and a third active material. The second active material comprises a lithium titanate material and the third active material is V2O5. The third active material exhibits charging and discharging capacity below a corrosion potential of the current collector of the negative electrode and above a decomposition potential of the first active material.