Mn(III) doped Li3V2-xMnx(PO4)(3)/C (x=0.2) is prepared by sol-gel method. Mn(III) is well substituted the position of V in Li3V2(PO4)(3) (LVP) without any Mn-contained impurity phase. The crystal structure and morphology in Mn-substituted Li3V2(PO4)(3) are studied by X-ray diffraction patterns (XRD), XPS and scanning and high-resolution transmission electronic microscopy (SEM and HRTEM). Mn(III) substitution increases the electrochemical performance of Li3V2(PO4)(3) at high cut-off voltage of 4.8 V. Li3V1.8Mn(III)(0.2)(PO4)(3) delivers 185 mAh g(-1) at 0.1 C, close to the theoretical capacity of Li3V2(PO4)(3), and delivers initial capacities of 130 and 126 mAh g(-1) at 5 C and 10 C-rate, remaining 95% and 97% of the initial capacities after 100 cycles when charged to 4.8 V. Mn(III) plays an important role in maintaining the three-dimensional (3D) solid framework structure to provide an improved cycle life at higher cut-off voltage of 4.8V and improving the high-rate performance of Li3V2(PO4)(3). (C) 2014 Elsevier Ltd. All rights reserved.