Mesoporous Li3V2(PO4)3@CMK-3 nanocomposite cathode material for lithium ion batteries

The mesoporous Li3V2(PO4)(3)@CMK-3 nanocomposite has been firstly synthesized by a sol-gel method. The X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen adsorption-desorption measurements show that the Li3V2(PO4)(3)@CMK-3 nanocomposite exhibits the pure monoclinic structure and mesoporous morphology. Li3V2(PO4)(3) has particle sizes of <50 nm, and are embedded in the mesoporous channels as well as well dispersed on the CMK-3 surface. Electrochemical measurements demonstrate that the Li3V2(PO4)(3)@CMK-3 nanocomposite shows significantly better rate capability and cycling performance than the bulk Li3V2(PO4)(3). In the potential range of 3.0-4.3 V, the Li3V2(PO4)(3)@CMK-3 nanocomposite delivers high initial discharge capacity of 130.0 mAh g(-1) at 0.2 C, and maintain an initial discharge capacity of 119.5 and 107.8 mAh g(-1), at 5 C and 10 C, respectively. After 300 cycles, it can still retain a discharge capacity of 95.4 and 73.5 mAh g(-1) at 5 C and 10 C, respectively. The good electrochemical performance for the Li3V2(PO4)(3)@CMK-3 nanocomposite are related to the special mesoporous structure, nanosized particles, and the existence of conductive carbon matrix, thus leading to improvement in electron and lithium ion diffusivity. (C) 2013 Elsevier B.V. All rights reserved.