Significant effect of electron transfer between current collector and active material on high rate performance of Li 4 Ti 5 O 12

The rate and cycling performances of the electrode materials are affected by many factors in a practical complicated electrode process. Learning about the limiting step in a practical electrochemical reaction is very important to effectively improve the electrochemical performances of the electrode materials. Li 4 Ti 5 O 12 , as a zero-strain material, has been considered as a promising anode material for long life Li-ion batteries. In this study, our results show that the Li 4 Ti 5 O 12 pasted on Cu or graphite felt current collector exhibits unexpectedly higher rate performance than on Al current collector. For Li 4 Ti 5 O 12 , the electron transfer between current collector and active material is the critical factor that affects its rate and cycling performances.