Enhancing Lithium Storage Performances of the LiTiO Anode by Introducing the CuVO Phase.

The low electronic conductivity of spinel-structured LiTiO could be improved by introducing CuVO. Herein, several LiTiO/CuVO composites with different CuVO contents have been successfully prepared by a facile liquid-phase dispersion technique. The amount of CuVO in composites is shown to affect the particle size and electrochemical performances of LiTiO. The LiTiO/CuVO composite prepared with a 5 wt % CuVO content (referred to as 5 wt % LiTiO/CuVO) exhibits the best electrochemical performances among all the LiTiO/CuVO composites. The initial discharge/charge capacities of the 5 wt % LiTiO/CuVO composite reach 241.1/199.8 mAh g and retain at 136.8/135.7 mAh g over 500 cycles at 30 mA g between 1.0 and 3.0 V. In addition, initial discharge/charge capacities of the 5 wt % LiTiO/CuVO composite amount to 129.8/90.5 mAh g even at 1200 mA g with maintained discharge/charge capacities of 71.1/71.1 mAh g over 2500 cycles, which are superior to the pristine LiTiO in all cases. The detailed electrode kinetic analysis reveals that the introduction of the CuVO phase can enhance the lithium-ion transferring rate and cycling stability of LiTiO. The enhanced lithium-storage mechanism of the 5 wt % LiTiO/CuVO composite is clarified by X-ray diffraction (XRD) analysis. The acquired data confirms that formation of small amounts of metallic Cu during discharge/charge processes highly enhance the electronic conductivity and decreases the charge-transfer resistance of LiTiO. In sum, the as-obtained 5 wt % LiTiO/CuVO composite has potential for future construction of high-rate and long-lifespan anode materials for Li-ion batteries. The work also provides an innovative route to improve electrochemical performances of LiTiO.