DU Peng, YAN Zihao, HUANG Shuo, CHEN Yongjun, LUO Lijie, LI Jianbao
(State Key Laboratory of Marine Resources Utilization in the South China Sea, School of Material Science and
Engineering, Hainan University, Haikou 570228, Hainan, China)

Abstract: In recent years, FeF₃ has become a promising lithium-free cathode material, due to its low cost and relatively high voltage platform. The preparation of FeF₃ with nanotubular structure by regulating the preparation process is reported. Physicochemical properties of FeF₃ , such as microstructure, surface morphology, crystal structure and phase composition, were characterized and analyzed. Electrochemical tests were performed with coin-type lithium-ion half batteries. At current density of 15 mA·g⁻¹, the battery reached a charge/discharge specific capacity of 130 mAh·g⁻¹. When the current density is varied from 15 to 600 mA·g⁻¹, by comparing the specific capacities at different current densities, it was found that the average charge/discharge specific capacity of the battery was just slightly decayed, showing high rate performance. At current density of 600 mA·g⁻¹, the Coulomb efficiency of the battery was maintained at near 100% and the capacity retention rate was about 95%, indicating cycle stability of the battery. Moreover, CoSe₂ was compounded with the FeF₃ nanotubes to further enhance the electrochemical performance of the battery. Both experimental theoretical results verified that It was experimentally and theoretically verified that FeF₃ with nanotubular structure exhibited excellent electrochemical performance, which was further boosted by forming composite with CoSe₂.
Key words: lithium ion battery; FeF₃; nanotubes; CoSe₂; modification; electrochemical performance