Designing Different Carbon Capping Amorphous MoO2 to Enhance Electrochemical Performance in Lithium-Ion Batteries

Transition metal oxides (TMOs) are considered a showing potential anode material for the lithium-ion batteries (LIBs) because of its high theoretical capacity. However, their use in LIBs is limited by factors such as low initial coulombic efficiency, substantial volume changes, and low electrical conductivity. Here, the amorphous MoO2 capped with different carbon is ingeniously designed by controlling the calcination temperature and different carbon sources. Electrochemical kinetic and material characterization show that the amorphous structure not only enhances its electronic conductivity, but also optimizes the lithium-ion (Li+) migration mode, thus improving its rate performance. Furthermore, the pore sizes produced by different carbon sources were found to have different effects on the performance of LIBs. Meanwhile, the Li+ storage mechanism of the amorphous MoO2-x@C was revealed by in-situ XRD analysis. As expected, the amorphous MoO2-x@C exhibits an excellent cycling stability, maintaining a discharge specific capacity of 601.4 mAh g−1 at 5.0 A g−1 for 800 cycles. Particularly, the MoO2-x@C||LiCoO2 full cell still possesses a capacity of 109.8 mAh g−1 at 0.2 C for 80 cycles. This endeavor will provide an experimental idea for the molybdenum-based oxide high-performance anode materials.