Facile synthesis of uniform MoO2/Mo2CTx heteromicrospheres as high-performance anode materials for lithium-ion batteries

Abstract Uniform nano/micro-spherical MoO 2 /Mo 2 CT x (T = O) heterostructures have been synthesized through a heterocatalytic reaction with subsequent facile calcinations. Given the high activity of H x MoO 3 /C precursors, this strategy opens a low-temperature route to realize the fabrication of nanocrystalline MoO 2 /Mo 2 CT x heterostructures, leading to achieve rapidly activated conversion reaction and extrinsic pseudocapacitive behaviour. Rather than carbon, highly conductive Mo 2 CT x decreases the charge transfer resistance in MoO 2 and maintains its structural stability upon lithiation/delithiation, ensuring the heterostructures with excellent cyclability ( e.g. , up to 833 mA h g⁻ 1  at 100 mA g⁻ 1 for 160 cycles with 95% capacity retention) and high rate capability ( e.g. , 665 mA h g⁻ 1  at 1 A g⁻ 1 ). Additionally, owing to the carbon-free characteristic, the secondary nano/microstructure feature and the suppressed surface oxidation trait, MoO 2 /Mo 2 CT x heterostructures, therefore, can deliver an improved initial Coulombic efficiency ( e.g. , up to 78% at 100 mA g⁻ 1 ). The present oxycarbide transformation and hybridization strategies are facile but effective, and they are very promising to be applied to converting other oxides–carbon composites into oxides/carbides heterostructures towards achieving higher electrochemical performance.