Enhancing lithium‐ion and electric conductive Li <sub>2</sub> FeSiO <sub>4</sub> cathode through in situ boron‐doping and carbon‐coating strategy
Haoxiang Li, Jiahui Zhu, Xiaobing Huang, Tao Zhou, Yurong Ren
Abstract
Abstract The extremely low electrical conductivity and ion‐diffusion coefficient of Li 2 FeSiO 4 limits its application as a cathode material in lithium‐ion batteries. Therefore, in situ boron‐doped Li 2 FeSi 1− x B x O 4− δ /C ( x = 0, 0.01, 0.03, 0.05 and 0.07) at the Si site was prepared via the solid‐state reaction method using pitch as the carbon source. B doping in the lattice structure and a carbon coating on the surface of the composites could effectively enhance the Li + /electron conductivity. Moreover, the reduced particle size of the active material with the relatively high specific area via boron‐doped modification could improve the wettability between the electrolyte and cathode. With the synergistic effect of appropriate boron doping and carbon coating, it exhibits a good rate performance, specific capacity, and cycling performance. As a result, the as‐prepared Li 2 FeSi 0.95 B 0.05 O 4− δ /C cathode showed a high discharge capacity of 160.7 mAh·g −1 at 0.2C, and the capacity retention rate was 96% after 100 cycles at 1.0C. This work presents an effective path for designing advanced cathode materials for lithium‐ion batteries.