Effect of Co-Doping in FeWO4 as Anode for Lithium-Ion Battery

FeWO4 and Fe1-xCoxWO4 compounds (x = 0.05, 0.1, 0.2, 0.3) were synthesized through a solvothermal method. As an anode material for lithium-ion batteries (LIBs), the Fe0.9Co0.1WO4 compound demonstrated high discharge specific capacity of 1188.6 mAh g(-1) after 100 cycles at 100 mA g(-1), which is much higher than that of FeWO4. Moreover, Fe0.9Co0.1WO4 exhibited the best rate performance and the best cyclic performance, as well as the lowest charge-voltage platform, among all Co-doped samples. The superior electrochemical performance of Fe0.9Co0.1WO4 was attributed to the Co doping with the appropriate amount, which led to a regular micron structure that ultimately promoted Li+ embedding and de-embedding. Furthermore, the synergistic effect of Co2+ and Fe2+ also enhanced the conductivity of the electrode material, which reduced electrode polarization during discharge and charge processes. Therefore, Fe0.9Co0.1WO4 is a promising anode material for LIB applications.