Preparation of LiCoO2 and LiCo1−xFexO2 using hydrothermal reactions

Iron doped/undoped LiCoO 2 powders could be obtained from hydrothermal reactions of either Fe 3+ or Co 3+ containing co-precipitates or a CoCl 2 -NaOH-NaClO 3 (oxidant) mixture with an excess amount of LiOH·H 2 O at 220 °C for 8-48 h. The LiFe x Co 1–x O 2 solid solution maintained a layered rock-salt structure until x=0.25. 57 Fe Mössbauer and Co K-edge XANES spectra and magnetic susceptibility data reveal that iron and cobalt in the solid solution are in high-spin Fe 3+ (S=5/2) and low-spin Co 3+ (S=0) configurations.