Synthesis and materials characterization of Li2MnO3–LiCrO2 system nanocomposite electrode materials

A series of Li[CrxLi(1−x)/3Mn2(1−x)/3]O2, (0.2 ≤ x ≤ 0.4) with nanocomposite structures was synthesized by a solution method with subsequent quenching. The sample structures were investigated by X-ray diffraction (Rietveld refinement), electron diffraction and HRTEM. According to co-indexed electron diffraction patterns and HRTEM images, Li[Cr0.211Li0.268Mn0.520]O2 was found to be composed of solid solution powders and Li[Cr0.290Li0.240Mn0.470]O2 and Li[Cr0.338Li0.225Mn0.436]O2 of nanocomposite powders indexed in monoclinic and hexagonal structure. Among the three compounds, the nanocomposite Li[Cr0.290Li0.240Mn0.470]O2 cathode prevented spinel-like structural transformation during cycling and delivered a good reversible capacity of about 195 mAh/g.