FutureCat researchers at the Universities of Warwick and Sheffield are applying advanced characterisation techniques, available through the UK’s national synchrotron science facility, Diamond Light Source, to unravel the role of oxygen redox (involving storing charge on oxide ions as well as transition metal ions) in high nickel layered oxide cathodes. Understanding this role offers the chance to access high capacities for next generation lithium-ion batteries.

Using resonant inelastic X-ray scattering (RIXS) measurements, researchers were able to directly observe oxygen involvement at high states of charge in a non-lithiumexcess, high nickel, layered oxide cathode. The high-resolution measurements show that the spectroscopic oxygen feature is the same as has been observed in Li-rich cathodes, suggesting a general mechanism is at play for oxygen redox in Li-excess and non-Li-excess systems. This observation could have broad implications in helping researchers to understand and harness oxygen redox for high energy density applications

Recently made available on ChemRxiv, the researchers demonstrated the result on a tungsten-doped, layered lithium nickel oxide material made at the University of Sheffield. This has been a collaborative project calling on expertise from around the FutureCat consortium to develop and refine the hypothesis. This research is now feeding in to FutureCat materials discovery and computational efforts to develop novel cathode materials.

Image: The I21 Resonant Inelastic X-ray Scattering (RIXS) spectrometer at the Diamond Light Source. Photo by Sean Dillow.

Case study published December 2022.