Preparation, structure and electrochemistry of LiFeBO3: a cathode material for Li-ion batteries

Abstract

LiMBO₃ (M = Fe, Co, Mn) has been identified as an interesting new cathode material for Li-ion batteries. It was shown to be difficult to synthesize the material as a pure phase and in a highly electrochemically active form. Here we report several methods for the successful preparation of LiFeBO₃, including traditional ceramic and self-combustion reactions. By decreasing the particle size and introducing in situ carbon coating, conventionally ceramic-synthesized LiFeBO₃/C yields a first discharge of 210 mA h g⁻¹ within the 1.5–4.5 V voltage window at a C/20 rate, 55 °C. Using high-resolution synchrotron X-ray diffraction, neutron powder diffraction and single crystal X-ray diffraction in combination with ⁶Li NMR and ⁵⁷Fe Mössbauer spectroscopies, we present a “1Fe 2Li” complex cation distribution model for LiFeBO₃ powder.