Study on the Solid Electrolyte Interface at the Surface of Anode Electrode in Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>/LiFePO<sub>4</sub> Battery System

A safe lithium-ion battery system of Li4Ti5O12/LiFePO4 was prepared, the solid electrolyte interface on the surface of Li4Ti5O12 electrode and the electrochemical performances of this lithium-ion battery system were studied. XRD、SEM and EIS texts were used to analyses the solid electrolyte interface on the surface of anode electrode. The result of XRD indicates that new material does generate at the surface of Li4Ti5O12 anode electrode. The result of EIS indicates that the SEI film increased the resistance of the battery, and the resistance will decrease as the cycle time increasing.