Copper incorporated in Li3V2(PO4)3/C cathode materials and its effects on high-rate Li-ion batteries.

Copper incorporated in Li 3 V 2 (PO 4 ) 3 /C cathode materials for high-rate Li-ion batteries were prepared by a self-catalysed sol-gel approach followed by a sintering process. The effect of copper incorporating amounts on the crystal structure, morphology and related electrochemical properties of Li 3 V 2 (PO 4 ) 3 /C was investigated. It is noteworthy that the impurity Li 3 PO 4 phase can be effectively affected by copper-incorporating without any significant influence on the surface morphology and crystal structure; moreover, the carbon layer coated onto Li 3 V 2 (PO 4 ) 3 -Cu 0.05 /C can be separated into the porous inner layer and the graphene-type outer layer. Benefiting from above two factors, copper-incorporated Li 3 V 2 (PO 4 ) 3 /C composite with improved electrochemical properties has been achieved. In comparison with pure Li 3 V 2 (PO 4 ) 3 /C, the Li 3 V 2 (PO 4 ) 3 -Cu 0.05 /C composite delivers a reversible specific capacity of 123.3 mAh g −1 after 50 cycles at a current rate of 1C and 116.2 mAh g −1 at 10C, maintaining 98.2% and 89.5% of capacity retention, respectively, and even cycled at 20C rate, it still possesses 105.4 mAh g −1 of discharge capacity, demonstrating an excellent rate capability and cycling stability. [ABSTRACT FROM AUTHOR]