The electrochemical synthesis of FePO4 on Pt was carried out in 0.01 M Fe(NO3)(3)center dot 9H(2)Oand 0.01 M (NH4)(2)HPO4 mixed aqueous solution for anodes in rechargeable lithium batteries. Compared with cathodic polarization curves of the deaerated and the cidified solutions, cathodic reactions in the mixed solution were verified into three regions, including I. 0.65 to - 0.27 V, O-2 + 4H(+) + 4e(-) -> 2H(2)O, II. -0.27 to - 0.95 V, 2H(+) + 2e(-) -> H-2 and 2H(2)PO(4)(-) + 2e(-) -> 2HPO(4)(2-) + H-2, and III. 2H(2)O + 2e(-) -> H-2 + 2OH(-). The deposition of iron phosphate was found at region II, where Fe(OH)(2+) + HPO42- + H2O -> Fe(OH)HPO4 proceeded. After deposition, the coated specimens were further annealed and characterized by inductively coupled plasma-atomic emission spectrometry, X-ray diffractometry, field emission scanning electron microscopy, Fourier transformation infrared spectrometry, thermogravimetric/differential thermal analysis and charge/discharge testing. It was found that the uniform as-deposited film was amorphous Fe(OH)HPO4 center dot H2O, dehydrated into Fe(OH)HPO4 at 200 degrees C, further condensed into FePO4, and fully crystallized into hexagonal structure at 600 degrees C. Also, the spongelike morphology of the annealed specimen was found full of nanopores and tuned with increasing temperature. The hexagonal iron phosphate coating film annealed at 600 degrees C for 10 h exhibited 757, 185, and 117 mAh/g for the first, the second, and the 50th cycle discharge test, respectively. (c) 2008 The Electrochemical Society. [DOI: 10.1149/1.2988061] All rights reserved.