Enhancing Lithium Storage Performances of the Li4Ti5O12Anode by Introducing the CuV2O6Phase

The low electronic conductivity of spinel-structured Li 4 Ti 5 O 12 could be improved by introducing CuV 2 O 6 . Herein, several Li 4 Ti 5 O 12 /CuV 2 O 6 composites with different CuV 2 O 6 contents have been successfully prepared by a facile liquid-phase dispersion technique. The amount of CuV 2 O 6 in composites is shown to affect the particle size and electrochemical performances of Li 4 Ti 5 O 12 . The Li 4 Ti 5 O 12 /CuV 2 O 6 composite prepared with a 5 wt % CuV 2 O 6 content (referred to as 5 wt % Li 4 Ti 5 O 12 /CuV 2 O 6 ) exhibits the best electrochemical performances among all the Li 4 Ti 5 O 12 /CuV 2 O 6 composites. The initial discharge/charge capacities of the 5 wt % Li 4 Ti 5 O 12 /CuV 2 O 6 composite reach 241.1/199.8 mAh g –1 and retain at 136.8/135.7 mAh g –1 over 500 cycles at 30 mA g –1 between 1.0 and 3.0 V. In addition, initial discharge/charge capacities of the 5 wt % Li 4 Ti 5 O 12 /CuV 2 O 6 composite amount to 129.8/90.5 mAh g –1 even at 1200 mA g –1 with maintained discharge/charge capacities of 71.1/71.1 mAh g –1 over 2500 cycles, which are superior to the pristine Li 4 Ti 5 O 12 in all cases. The detailed electrode kinetic analysis reveals that the introduction of the CuV 2 O 6 phase can enhance the lithium-ion transferring rate and cycling stability of Li 4 Ti 5 O 12 . The enhanced lithium-storage mechanism of the 5 wt % Li 4 Ti 5 O 12 /CuV 2 O 6 composite is clarified by in situ X-ray diffraction (XRD) analysis. The acquired data confirms that in situ formation of small amounts of metallic Cu during discharge/charge processes highly enhance the electronic conductivity and decreases the charge–transfer resistance of Li 4 Ti 5 O 12 . In sum, the as-obtained 5 wt % Li 4 Ti 5 O 12 /CuV 2 O 6 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 Li 4 Ti 5 O 12 .