Solid State Ionics, Vol.259, 46-52, 2014
Synthesis and electrochemical properties of Co-doped Li9V3(P2O7)(3)(PO4)(2)/C as cathode materials for lithium-ion batteries
A series of Co-doped Li9V3 Co--x(x)(P2O7)(3)(PO4)(2)/C (x = 0.00-0.10) compounds have been prepared by sot-gel method and the Rietveld refinement results indicate that pure-phase Li9V3 Co--x(x)(P2O7)(3)(PO4)(2)/C (x = 0.00-0.10) compounds with trigonal structure can be obtained. Their electrochemical performance has been investigated and the results show that, although the initial specific capacity decreased with Co doping at a lower current rate, both cycle performance and rate capability have excited improvement with proper Co-doping content. Li9-V2.96Co0.04(P2O7)(3)(PO4)(2)/C compound presents the best cyclic ability and rate performance. The enhancement of cyclic ability and rate performance may be attributed to enhanced specific surface area and improved lithium-ion diffusion during the proper amount of Co-doping (x = 0.04) in V sites. (C) 2014 Elsevier B.V. All rights reserved.