A green process route to recycle LiFePO4/C electrode materials is proposed in this work. First, a robust strategy to synthesize the LiFePO4/C cathode materials from a precursor of a crystalline FePO4·2H2O phase (metastrengite I) is presented. In order to prepare the crystalline FePO4·2H2O, the solution precipitation route is adapted, where the reaction conditions such as temperature and pH are precisely controlled. Among various heat treatment temperatures to calcinate our prepared FePO4·2H2O with the lithium sources, we find that the LiFePO4/C cathode materials synthesized at 700 °C deliver a maximum discharge capacity of 168.51 mAh g-1 at 0.1 C (1 C rate = 170 mAh g-1) with the capacity retention of 99.36 % after the 25th cycle at 1 C. Furthermore, the commercially available LiFePO4 powders and the recovered LiFePO4 electrode materials from the spent batteries are both tested with our developed recycling process, where we decompose the LiFePO4 powders/electrodes to prepare the crystalline FePO4·2H2O then re-synthesize the LiFePO4/C cathode materials. In both cases, our recycled LiFePO4/C exhibit very a comparable discharge capacity of ~140 mAh g-1 at 1 C with capacity retention of ~99 %.