An economical and scalable synthesis route of LiFePO4 nanoplate precursors is successfully prepared in pure water phase under atmosphere without employing environmentally toxic surfactants or high temperature and high pressure compared with traditional hydrothermal or solvothermal methods, which also involves recycling the filtrate to regenerate LiFePO4 nanoplate precursors and collecting by-product Na2SO4. The LiFePO4 precursors present a plate-like morphology with mean thickness and length of 50–100 and 100–300nm, respectively. After carbon coating, the LiFePO4/C nanoparticles with particle size around 200nm can be observed which exhibit a high discharge capacity of 160mAhg−1 at 0.2C and 107mAhg−1 at 20C. A high capacity retention closed to 91% can be reached after 500 cycles even at a high current rate of 20C with coulombic efficiency of 99.5%. This work suggests a simple, economic and environmentally benign method in preparation of LiFePO4/C cathode material for power batteries that would be feasible for large scale industrial production.