Controlling NMC Particles by Selecting Co-Precipitation Technique

J.L. Durham, O. Kahvecioglu Feridun, A.L. Lipson, S. Aryal, K.Z. Pupek
Argonne National Laboratory,
United States

Keywords: NMC, Ni-rich cathode, Li-ion battery, cathode, battery manufacturing, co-precipitation, CSTR, TVR, NMC622, NMC811

Summary:

The widespread usage of portable electronics and growing interest in electric and hybrid vehicles has generated a mass market for safer batteries with increased energy density. Nickel-rich cathodes such as LiNi0.6Mn0.2Co0.2O2 (NMC622) and LiNi0.8Mn0.1Co0.1O2 (NMC811) have received considerable attention as a result of their high capacity and decreased cost compared to higher cobalt content materials such as LiCoO2 or LiNi1/3Mn1/3Co1/3O2 (NMC333). We conducted a systematic study on how co-precipitation technique impacts particle size and morphology of NMCs. This talk will present co-precipitation results of NMC622 and NMC811 produced from two different reactor designs, either a typical continuous stirred tank reactor (CSTR) or more advanced Taylor vortex reactor (TVR). Particle properties (i.e. morphology, density, size, and particle size distribution) of materials produced in a reactor via co-precipitation are typically controlled by the temperature, pH, stirring speed, residence time, and impeller design. TVR has an advantage for producing Ni-rich cathodes due to its strong micro-mixing zones which allows for the continuous production of small particles (less than 5 micrometers) with high density at reduced residence times (less than 4 hours) which cannot be achieved using conventional CSTR methods. The effect of particle properties on the electrochemical performance and thermal stability of NMC622 and NMC811 manufactured using CSTR and TVR methods will also be discussed. Both reactors, the CSTR and TVR have been used in our facility to manufacture kilogram quantities of optimized NMC622 and NMC811 precursor in a continuous process mode.