Chemically oxidized γ-MnO2 for lithium secondary batteries: structure and intercalation/deintercalation properties

摘要

Structural changes of chemically lithiated γ-MnO2 during chemical oxidation were characterized by X-ray diffraction combined with a stacking fault analysis and neutron total scattering with a local structure analysis. Lithium ions intercalate into the crystallographic sites around "Ruetschi" protons prior to those around "Coleman" protons for the chemically lithiated γ-MnO2. The "Ruetschi" and "Coleman" protons have O-H bond lengths of 1.2 A and 1.9 A, respectively, which decreased after the chemical oxidation. The chemically intercalated lithium ions are placed at the center of oxygen octahedra with an O-Li length of 1.9 A.