Electrochemical Synthesis of FePO4 for Anodes in Rechargeable Lithium Batteries

Abstract

The electrochemical synthesis of on Pt was carried out in and mixed aqueous solution for anodes in rechargeable lithium batteries. Compared with cathodic polarization curves of the deaerated and the acidified solutions, cathodic reactions in the mixed solution were verified into three regions, including I. , , II. , and , and III. . The deposition of iron phosphate was found at region II, where 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 , dehydrated into at , further condensed into , and fully crystallized into hexagonal structure at . 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 for exhibited 757, 185, and for the first, the second, and the discharge test, respectively.