Structural and electrochemical study of Cr-substituted layered manganese oxide cathode materials

A lithiated layered Mn–Cr compound, Li[Cr0.29Li0.24Mn0.47]O2 was synthesized by a solution method with subsequent quenching. The crystal structure was investigated by X-ray diffraction (Rietveld refinement) and Electron diffraction showing co-existence of rhombohedral and monoclinic structures. According to the co-indexed electron diffraction patterns and HRTEM images, Li[Cr0.29Li0.24Mn0.47]O2 electrode was composed of nano-scale domains indexed in monoclinic and hexagonal structures, simultaneously. The nano-composite cathode successfully prevents spinel-like structural transformation during cycling and delivered a good reversible capacity of about 195 mAh/g between 2.4 and 4.7 V.