Preparation of high tap-density 9LiFePO4•Li3V2(PO4)3/C composite cathode material by spray drying and post-calcining method

The 9LiFePO(4)center dot Li3V2(PO4)(3)/C composite cathode material is synthesized by spray-drying and post-calcining method based on citrate. The composite is well crystallized, and contains olivine-type LiFePO4 and monoclinic Li3V2(PO4)(3) phases. The composite material exhibits spherical particles in the size of 0.5-5 mu m, and shows a high tap-density of 1.64 g cm(-3). The electrochemical performance of the material is excellent. At 5C and 10C rates, the sample exhibits the initial discharge capacities of 135.3 and 109.6 mAh g(-1) and capacity retentions of 96.2% and 93.7% after 100 cycles, respectively. The homogenous mixing of the LiFePO4 and fast ion conductor additive Li3V2(PO4)(3), which is resulted from spray-drying, can be the reason why the composite has good rate capability. (C) 2011 Elsevier B.V. All rights reserved.