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

FeWO₄ and Fe_1−xCo_xWO₄ 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 Fe_0.9Co_0.1WO₄ 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, Fe_0.9Co_0.1WO₄ 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 Fe_0.9Co_0.1WO₄ 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, Fe_0.9Co_0.1WO₄ is a promising anode material for LIB applications. [ABSTRACT FROM AUTHOR]