Synthesis And Electrochemical Properties Of Manganese Oxide Nano Materials

Manganese oxides as cathode materials for lithium ion batteries have been widely studied because of their good electrochemical properties,low preparation cost and no pollution.Among them,spinel LiMn₂O₄ with good cycle stability and layered LiMnO₂ with higher theoretical capacity are the representatives.In this study,LiMn₂O₄ and LiMnO₂ cathode materials with different morphologies were prepared by hydrothermal method and high temperature solid state method.The crystal structure of the final product was measured by XRD,SEM,HR-TEM,constant current charge/discharge and electrochemical impedance spectra?EIS?.The formation mechanism and electrochemical properties of morphology were analyzed and discussed.The spherical LiMn₂O₄ was prepared by hydrothermal method and high temperature solid state method.The effects of different lithium sources on the morphology and electrochemical properties of the products were investigated.Cubes and spheres LiMn₂O₄ were prepared by organic solvent assisted hydrothermal method and high temperature solid phase method.The effects of the amount of organic solvent on the morphology of the precursor product and the electrochemical properties of the final product were investigated.The layered LiMnO₂ cathode materials of cubes and spheres were synthesized by hydrothermal method.The effects of hydrothermal temperature on the morphology and electrochemical properties of the final products were investigated.The 1-D layered LiMnO₂ cathode material was synthesized by secondary hydrothermal method.The effects of hydrothermal temperature and reducing agent addition on the structure,morphology and electrochemical properties of LiMnO₂ were studied.