Detecting O-O diatomics trapped in high energy density Li-ion battery cathode materials using Inelastic Neutron Scattering

The energy density of Li-ion batteries is currently restricted by the cathode material, typically a layered Li transition metal (TM) oxide. High energy densities can be accessed in Li-rich materials, such as Li1.2Ni0.13Mn0.54Co0.13O2, by oxidising the oxide ions in the crystal lattice in addition to the TMs present, however, this reaction triggers severe structural rearrangement, including suspected dimerization of oxidised oxide ions to form O-O bonds. Characterising these in the bulk of a solid inorganic material is very challenging, and conclusive identification remains elusive. We propose to use Inelastic Neutron Scattering to record the vibrational spectra of samples of Li1.2Ni0.13Mn0.54Co0.13O2 collected before and after O-oxidation across the range of frequencies expected from O-O diatomics to detect the appearance any O-O diatomic that may be present.