Fast growth of the precursor particles of Li(Ni0.8Co0.16Al0.04)O2 via a carbonate co-precipitation route and its electrochemical performance

Abstract

We co-precipitated the precursor of a nickel-rich cathode material with high energy density—layered lithium nickel cobalt aluminum oxide (NCA, Li(NixCoyAl1−x−y)O2)—via a carbonate route, and we tested the cell performance of NCA synthesized from this precursor. The precursor for NCA had been previously co-precipitated via a hydroxide route, with a long residence time that caused low productivity. We obtained spherical precursor particles with uniform particle size distribution through the carbonate route. We found that the precursor has the form of (Ni0.8Co0.16Al0.04)(CO3)0.41(OH)1.18 and the precursor particles grow much faster than the hydroxide form with the same metal composition, (Ni0.8Co0.16Al0.04)(OH)2. The faster particle growth rate is attributed to the low solubility of the precursor in mild pH condition of co-precipitation (pH = 8.0). NCA from this precursor showed an initial discharge capacity of 183 mAh/g at 0.1C-rate, while retaining 91% of its capacity after 100 cycles representing improved performance over those of NCA from the hydroxide route with the same residence time. We believe faster particle growth, uniform particle size distribution, and morphology to be the reasons for the improved performance.