fig6

Figure 6. (A) 1s-4p peak energy in the initial cycle showing almost no change in the environment around Ni and Co on charging across the 4.5 V plateau^[83]. (B) Compositional phase diagram showing the electrochemical reaction pathways for a xLi₂MnO₃·(1-x)LiMO₂ electrode^[9]. (C) Operando mass spectrometry of ¹⁸O-labelled Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ cathode during the initial cycle^[83]. (D) O K-edge mRIXS of a series of Li₂RuO₃ electrodes at different electrochemical states. The solid red arrows indicate the striking, sharp features of oxidization at the high voltage state. (i-vii) represent the mRIXS of Li₂RuO₃ at the state of the pristine, charged to 4.1 V, charged to 4.2 V, charged to 4.6 V, discharged to 3.8 V, discharged to 3.35 V, and discharged to 2.0 V, respectively. (viii) Summary of Ru and O redox during the initial cycling profile with blue for lattice Ru^4+/5+ and yellow for lattice oxygen redox^[28]. (E) Charge-discharge profiles of Li_2-xIr_1-ySn_yO₃ for a full cycle (black) and for ~1.5 e^- in Ir per cycle (pink)^[29]. (F) Enlarged ABF-STEM image. The O-O pairs arise from twisting the opposite triangular faces of the IrO₆ octahedra (shown in yellow)^[11]. (G) O K-edge mRIXS of Li₂Ir_0.75Sn_0.25O₂ and Li₂Ir_0.75Sn_0.25O₂ charged to 4.60 V showing a localized RIXS feature at 530.7 eV excitation energy and 522.8 eV emission energy^[29]. mRIXS: Mapping of resonant inelastic X-ray scattering.