Enhanced charge storage of Li3FeF6 with carbon nanotubes for lithium-ion batteries

Due to stability in the air, easy preparation process, lower cost and high reaction potential, Li3FeF6 is a promising cathodic material in lithium-ion batteries. However, the poor electronic conductivity of Li3FeF6 limits its performance in lithium-ion batteries. Conductive agent addition can improve the electronic conductivity of Li3FeF6 composite electrodes. The specific capacity of the Li3FeF6/C electrode is around 80 mA h g(-1) (the highest value), corresponding to 0.57 Li+ embedding. While a specific capacity of the Li3FeF6/CNTs electrode of 120 mA h g(-1) can be achieved, which is close to the theoretical capacity (140 mA h g(-1)), and the reversible capacity can be maintained at above 100 mA h g(-1) after 50 cycles, with a capacity retention of 83%, which indicates greater electrochemical activity for such a CNT containing electrode. The enhanced performance of the Li3FeF6/CNTs electrode is due to the lower interface resistance and improved electrochemical activity of the Li3FeF6 active material.