FeF3 Nanoparticles Embedded in Activated Carbon Foam (ACF) as a Cathode Material with Enhanced Electrochemical Performance for Lithium Ion Batteries

摘要

Iron trifluoride (FeF3) has been actively studied as an alternative cathode material due to its cost effectiveness, low toxicity, and high theoretical capacities of 237 and 712mAhg(-1) at 2.0-4.5V and 1.5-4.5V, respectively. In spite of these advantages, FeF3 has serious shortcomings of poor electronic conductivity and a slow diffusion rate of lithium ions, leading to a lower reversible specific capacity than its theoretical value. In this work, we prepared FeF3/activated carbon foam (ACF) nanocomposites by impregnating FeF3 nanoparticles in the mesoporous ACF. The FeF3/ACF nanocomposites showed improved electrochemical performances compared to bulk FeF3. For example, the FeF3/ACF nanocomposites showed an initial discharge capacity of 195mAhg(-1) at 0.1C with a capacity retention of similar to 93% during 50 cycles in the voltage range 2.0-4.5V. The cycling stability at 1.5-4.5V was also superior to that of bulk FeF3.