Recent advances in energy materials have led to the development of high capacity insertion cathodes for Li-ion batteries. One of the most promising of these materials is lithium nickel manganese cobalt oxide (NMC). For all insertion electrodes, lithium diffusion ultimately governs all electrochemical activity. Generally, the easier lithium can diffuse through the structures, the greater the electrochemical properties. However, lithium diffusion has yet to be experimentally characterised on a local scale for NMC, a highly attractive material for commercial application. Thus, this study proposes investigation into the lithium diffusion properties in NMC, the effect of particle size and the effect of nickel concentration (which has previously been shown to increase diffusive properties) in one complete study.