The development of high energy density electrode materials is increasingly important for EV applications. Chief amongst these are the layered oxide materials LiNixMnyCozO2, where increased nickel content can increase the overall energy density (e.g. NMC-622, NMC-811). Although many benefits arise from high nickel content cathode materials, several new challenges arise including increased degradation over long term cycling. One strategy to alleviate this is to dope with, for example, small amounts of aluminium. The nature of this and the mechanism by which doping improves capacity retention is not well understood. We propose to investigate a series of high nickel content NMCs (pristine and doped) to investigate this effect and determine the benefits of the synthetic methodology applied.