Structural and electrochemical study of Li[CrxLi(1-x)/3Mn2(1-x)/3]O2 (0≤x≤ 0.328) cathode materials

Li[CrxLi(1-x)/3Mn2(1-x)/3]O-2 with x=0, 0.05, 0.1 and 0.328 were synthesized by a solution method with subsequent quenching. The structures were investigated by X-ray diffraction (XRD), Rietveld refinement, electron diffraction and HRTEM. Li[CrxLi(1-x)/3Mn2(1-x)/3]O-2 (x=0 and 0.05) and annealed Li[Li1/3Mn2/3]O-2 were indexed based on the monoclinic structure, while Li1.2Cr0.4Mn0.4O2 was shown to be that of a nanocomposite. Li[Cr0.1Li0.29Mn0.602]O-2 material formed based on the stoichiometry in between Li[Li1/3Mn2/3]O-2 and Li[Cr0.328Li0.22Mn0.436]O-2 showed both sides features of the monoclinic and hexagonal structures in a nanocomposite structure and provided the lack of a developed anodic peak between 4.6 and 4.9 V, a good reversible capacity of around 250 mAh/g in a discharge voltage range between 2.8 and 3.5 V. (C) 2006 Elsevier B.V. All rights reserved.