Oxygen redox reactions in Li ion battery electrodes studied by resonant inelastic X-ray scattering

We present results using inelastic scattering X-ray spectroscopy (RIXS) combined with X-ray absorption spectroscopy on Li ion battery cathode and anode materials, respectively. In particular, we discuss results obtained on the cathode materials Li1.2[Ni0.13Co0.133Mn0.544]O2 and Lix[Ni0.65Co0.25Mn0.1]O2 as well as in the composite anode material Ni0.5TiOPO4/C. We show that oxygen redox reactions are an important aspect of many such systems and how one can successfully address them using RIXS. New insights on the formation of new oxygen species and on the details of cycling-induced structural disorder can be detected. We foresee a particular future focus on these issues considering the rapid development of new operando RIXS techniques for Li ion battery research.