Synthesis and electrochemical characterization of high rate capability Li3V2(PO4)3/C prepared by using poly(acrylic acid) and d-(+)-glucose as carbon sources

Submicron-structured Li3V2(PO4)3/C has been synthesized by carbon-thermal reduction method with poly(acrylic acid) and d-(+)-glucose as carbon sources. The pure monoclinic structure of Li3V2(PO4)3/C has been confirmed by XRPD and Rietveld refinement, scanning electron microscopy, and transmission electron microscopy. The specific capacity of Li3V2(PO4)3/C as cathode has been evaluated, between 3.0 and 4.3 V vs Li+/Li, in the two different electrolytes: 1 M solution of LiPF6 in EC:DMC (1:1) at room temperature and in EC:DMC:DEC (1:1:1) at low temperature (0 and −20 °C). Because of the submicron-size dimensions of Li3V2(PO4)3 and of the good carbon coating, the material discharge capacities as high as 103, 98 and 81 mAh g−1 at 40, 60 and 100C rates, retains 93% of the initial discharge capacity after 1000 cycles at 100C. The performances even at low temperature are also good with values of the order of 84, 40, 23, 19 mAh g−1 at 0 °C and 69, 24, 19, 15 mAh g−1 at −20  °C at 3, 7.5, 15, 30 C-rates, respectively.