Modelling particle size distributions of co-precipitated NCM cathode material precursors for SIBs

Sodium-ion batteries (SIBs) are currently considered for grid energy storage applications. The synthesis of the cathode material of a battery plays an important role in attaining the desired electrochemical performance. The particle size distribution of the cathode material crystals, in particular, impacts ionic diffusion, sodium-ion intercalation, cyclic stability, tap density, and energy density. The determination of particle size distribution of cathode material using mathematical modelling is the central theme of this work. A semi-batch stirred reactor is used to study the reactive coprecipitation of Nickel, Cobalt, and manganese carbonate (NCM) as a mixed metal oxide precursor salt. The particle size distribution resulting from co-precipitation is modelled via Population Balance modelling, which is implemented by Kinetic Monte Carlo methods. The effect of pH, type of precipitating agent, and ratios of the metal precursor salts on the particle size distributions of the crystallites have been examined. The experimental particle size distributions have been correlated with the simulated predictions. The process conditions are optimised to obtain the desired particle size distribution, which will determine the electrochemical properties of cathode materials.