Hydrothermal synthesis of LiFePO4 as a cathode material for lithium batteries

LiFePO4 (space group: Pnma) was prepared by hydrothermal method at 170 °C. LiFePO4 was prepared from precursor solutions consisting of FeSO4 · 7H2O, (NH4)2HPO4, and three kinds of Li sources. LiCl, Li(CH3COO), and LiOH · H2O were used as Li sources. The pH of the precursor solution varied depending on Li source. The particle size, particle shape, and crystal texture of the obtained LiFePO4 changed depending on pH. The electrochemical properties of the prepared LiFePO4 were characterized as a cathode material for lithium batteries in an organic electrolyte at room temperature. The LiFePO4 particle prepared from the precursor solution with Li(CH3COO) was flake-like crystal (particle size: 1–2 μm) and had a preferred crystal orientation with a (020) texture. This LiFePO4 exhibited a discharge capacity of 147 mA h g−1, which was 85% of the theoretical capacity 170 mA h g−1.