FePO4·xH2O precursor was synthesized by using raw materials, FeSO4·7H2O waste slag and H3PO4, without any purifying process. Crystalline metals-doped LiFePO4 was prepared by heating an amorphous LiFePO4. The amorphous LiFePO4 was obtained via a novel ambient temperature reduction method, using the as-prepared FePO4·xH2O, oxalic acid and Li2CO3 as raw materials. ICP analysis confirms that a small amount of Ti, Al and Ca deposited in precursor. XRD and Rietveld-refined results show that the metals-doped LiFePO4 is single olivine-type phase and well crystallized, Ti atoms occupy Li (M1) site, resulting in the formation of cation-deficient solid solution. From SEM and corresponding elemental mapping images, it could be found that the particle size of LiFePO4 is about 200–500nm, and the distribution of elements (Fe, P and Ti) is homogeneous. The electrochemical performance of LiFePO4 cathode was evaluated by galvanostatic charge/discharge test. The results indicate that the metals-doped LiFePO4, prepared from the FeSO4·7H2O waste slag, delivers a capacity of 161, 153, 145, 134 and 112mAhg−1 at 0.1C, 0.5C, 1C, 2C and 5C rate, respectively, and shows an excellent cycling performance at moderate current rates (up to 2C).