Stable cycle-life properties of Ti-doped LiFePO4 compounds synthesized by co-precipitation and normal temperature reduction method

Submicron-sized LiFePO₄ and Ti-doped LiFePO₄ cathode materials were synthesized by a reformative co-precipitation and normal temperature reduction method, for which Ti ions were added in the process of preparing precursors to pursue a kind of sufficient and homogenous doping way. ICP and XRD analyses indicate that Ti ions were sufficiently doped in LiFePO₄ and did not alter its crystal structure. It is noted that higher Ti ions doping levels are conducive to electrochemical performance of LiFePO₄, especially on the aspect of stable cycle-life at higher C rates. The sample doped with 3 at% Ti shows the most impressive cycling performance, even after 100 cycles, discharge capacity of 133 mAh g⁻¹ was obtained (102.3% of its initial value) at 1C rate, and the discharge decreased little from 124 to 120 mAh g⁻¹ (96.8% of its initial value) at 2C rate.