Synergistic interaction of vortex capture and fluid shear in Ni-rich cathode precursor growth process

The hydrodynamics caused by agitation in the reactor is a crucial factor for the particle geometry during the reactive crystallization. Herein, we investigated the morphology and microstructure evolution of Ni-rich cathode precursor particle under different impellers including Propulsive Impeller, Radial Impeller, Rushton Impeller and Axial-radial Composite Impeller. The computational fluid dynamics (CFD) simulation results demonstrated that Axial-radial Composite Impeller has synergistic interaction of strong vortex capture and weak shear interference, and more importantly, the mass transfer is enhanced by simultaneously improving the micro and macro mixing performance. After the lithiation reaction, LiNi0.89Co0.05Mn0.05Al0.01O2 cathode with tightly ordered stacking structure were obtained controllably, which can effectively alleviate localized stress to inhibit intergranular cracks and relieve the structure decay. Hence, the regulated LiNi0.89Co0.05Mn0.05Al0.01O2 cathode using by the Axial-radial Composite Impeller has better structural stability and electrochemical performance with a capacity retention of 91.57 % after 100 cycles at 1C in 2.7 ∼ 4.3 V. Moreover, this study provides a universal idea to achieve controllable preparation of precursors and structural design for layered oxide cathodes.