Effect of Ti doping on LiFePO4/C cathode material with enhanced low-temperature electrochemical performance

A series of LiFePO4/C composites with Ti in-situ doped has been synthesized by a combination of wet ball-milling, spray drying, and carbothermal reduction. The test result shows that the composite ion doping can significantly improve the electrochemical performance of the material. The discharge specific capacity of the button cell at 0.2C is 160.2 mAh g(-1). After 500 cycles, the battery capacity remained 96.8% of the initial discharge capacity, which shows an excellent rate discharge performance and cycle performance. The study found that the appropriate amount of Ti doping does not much affect the crystal structure, but the particle size of the primary particles exhibits a trend of nanocrystallization, which could effectively shorten the deintercalation distance of Li+. Especially the low-temperature performance of the Ti doping LiFePO4, there was the highest discharge capacity of 122.3 mAh g(-1) at 1C and - 20 degrees C. But the excessive doping of Ti could cause the deformation and blockage of lithium-ion channels, which reduced the lithium-ion diffusion coefficient. Besides, the 14,500 cylindrical batteries were performed to verify the effectiveness of application, which could reach a 148.8 mAh g(-1) at 1C rate.