Electrochemical Performance of FeF3·0.33H2O/MWCNTs Composite Cathode Synthesized by Solvothermal Process

This paper reports a FeF3·0.33H2O/multi-walled carbon nanotubes (MWCNTs) composite for energy storage applications. The composite material is prepared by solvothermal reaction with FeF3·3H2O and MWCNTs as precursors, and FeF3·3H2O was removed of crystalliferous water and converted to FeF3·0.33H2O during solvothermal treatment. Structural characterizations show that FeF3·0.33H2O that crystalline with a diameter of about 30 nm were distributed in the network of MWCNTs. As a cathode material for lithium ion batteries, FeF3·0.33H2O/MWCNTs was superior to pure FeF3·0.33H2O in terms of high capacity (an initial capacity of 181 mAh g-1 in 2.0-4.3 V at 20 mA g-1), good cycleability (50% capacity retension at 50th cycle) and good rate capability (116 mAh g-1 at 100 mA g-1). The enhanced performances were attributed to the conductive MWCNT network which improved the electron transport ability and buffered volume change of the cathode.