Improving electrochemical properties of Li4Ti5O12/TiO2 diphase anode materials via Co-Cl co-doping

The rapid development of highly durable electric vehicles has put forward higher requirements for lithium-ion batteries. Li 4 Ti 5 O 12 (LTO) is widely studied owing to its long service life and safety. However, owing to their low electrical conductivity and diffusion, lithium ions have limited practical applications. In this study, Co-Cl co-doped LTO/TiO 2 diphase (LTOT) nanosheets were prepared via the hydrothermal method . The synergistic effect of Co-Cl co-doping reduced the charge-transfer resistance of LTOT and increased the lithium-ion diffusion coefficient , thereby improving the dynamic behavior of the electrode material, which further enhances the rate capability and cycle performance of LTOT. The optimized LTOT:Co-Cl composite exhibited excellent cycle performance and rate capability (the ninth cycle reversible capacities were 253.8, 222.2, 200.1, 185.7, 169.9, 161.3, and 146.3 mAh·g −1 at the current density of 1, 2, 5, 10, 20, 30, and 50 C (1 C = 175 mA·g −1 ) rate, respectively). In addition, LTOT:Co-Cl maintained a capacity of 120 mAh·g −1 after 5000 cycles at 50 C with a retention rate of 83 %, indicating that the average decay rate per cycle is only 0.003 % during the long charge/discharge process.