High-Temperature Electrochemical Performance of FeF₃/C Nanocomposite as a Cathode Material for Lithium-Ion Batteries

Iron trifluoride has been studied as a cathode material due to its cost-effectiveness, low toxicity, and high theoretical capacities of 712 mA h g⁻¹. However, FeF₃ has serious shortcomings of poor electronic conductivity and a slow diffusion rate of lithium ions, leading to a lower reversible specific capacity. In this work, FeF₃/C nanocomposite has been synthesized successfully via a high-energy ball-milling method, and acetylene black is used as the conductive agent to improve the conductivity of FeF₃. The FeF₃/C nanocomposite shows a high initial discharge capacity of 346.25 and 161.58 mA h g⁻¹ after 40th cycle at 50 mA g⁻¹. It exhibits good cycle performance and rate performance. The high-temperature discharge capacities decreased with increase in the temperature. The initial high-temperature discharge capacities are found to be 254.17, 300.01, 281.25 and 125.16, and 216.875, 156, 141.67, 150, and 64.98 mA h g⁻¹ at 20th cycles at the 40, 50, 60, and 70 °C, respectively.