Combined First-principles and Experimental Studies of a V-doped LiFePO4/C Composite as a Cathode Material for Lithium-ion Batteries
Qunfang Zhao, Shuqiong Zhang, Chang Wang, Guanghui Jiang, Min-yi Hu, Zhaoyong Chen, Quansheng Ouyang
Abstract
As a promising cathode material for lithium-ion batteries (LIBs), olivine-structured LiFePO 4 has been increasingly studied due to its high capacity, excellent thermal stability, cycling stability and environmental friendliness. Nevertheless, the main challenge of LiFePO 4 is its poor conductivity and Li + diffusion coefficient. Herein, a V-doped LiFePO 4 /C composite is prepared via a solid-state method. The electronic structures of the samples are obtained by first-principles calculations based on density functional theory. V2 exhibits enhanced electrochemical performance, demonstrating discharge capacities as high as 155.6, 150.2, 136.0, 122.4 and 93.1 mA h g -1 at 0.1, 0.2, 0.5, 1.0 and 3.0C, respectively, and approximately 100% capacity retention after 100 cycles at 1.0C.