We focus on revealing experimentally the change of the electronic structure, especially in the Fe 3d states through Li intercalation / deintercalation for LiFePO4, pyrophosphate iron compound Li2FeP2O7, Li2Fe1-xMnxP2O7 with Mn substitution, and Na pyrophosphate iron compound Na2FeP2O7. For nano and operando analysis of cathode materials, we performed pin-point photoelectron spectroscopy and soft X-ray emission spectroscopy (XES) of LiMn2O4, respectively. Based on these electronic structure analysis, we tried to develop a lithium-peroxide battery with Co-doped Li2O cathode for higher specific energy density, where O and Co X-ray absorption spectroscopy was used to reveal electronic states.

报告人简介：2006 –, Director, The University of Tokyo Synchrotron Radiation Research Organization Publications: about 570 original papers 1. "Selective probing of the OH and OD stretch vibration in liquid water using resonant inelastic soft X-ray scattering" Phys. Rev. Lett. 111, 193001 (2013). 2. "Spin-filter tunnel junction with matched Fermi surfaces” Phys. Rev. Lett. 109, 076602 (2012). 3. "Metallic quantum well states in artificial structures of strongly correlated oxide" Science 333, 319-322 (2011). 4. "Origin of metallic states at the heterointerface between the band insulators LaAlO3 and SrTiO3" Phys. Rev. Lett. 101, 026802 (2008). 5. "In-situ photoemission study of Pr0.7Ca0.3MnO3 epitaxial thin films with suppressed charge fluctuations" Phys. Rev. Lett. 100, 026402 (2008). 6. "Nature of well-screened state in hard x-ray Mn 2p core level photoemission of La1-xSrxMnO3 films", Phys. Rev. Lett. 93, 236401 (2004).