How to Optimize the Synthesis of Ni1-y-ZMnyCoz(OH)2, y+z≤0.20, in a Continuous Stirred Tank Reactor (CSTR)

Abstract

LixNi1-y-zMnyCoz(OH)2 for y+z≤0.20 or Ni-rich NMCs are state-of-the-art cathode materials. As they have high energy density, they are used in present electric vehicles like Nissan Leaf S Plus, BMW i3, Chevrolet Bolt and many more. Pioneering research has been going on in the battery community to push the Ni-content further or to stabilize the capacity retention of current NMC materials used in market. These efforts include, studying the capacity fading on long cycling, coating, or doping the pristine NMCs, etc. All these research works need a good baseline material to work with which is often complex to synthesize due to the involvement of the complex reaction mechanism, which is not very well understood. Hence most of the researcher limits themselves to commercially available NMC materials which may differ from batch to batch, and it also reduces the flexibility to modify the material.In this presentation, we will discuss our detailed study of the reaction mechanism to optimize the Ni-rich NMCs from their respective sulfate salts on a 2L bench-top continuous-stirred tank reactor. The synergistic effect between the pH control, strong base, complexing agent, temperature, and other physical factors which are involved in the formation of the desired dense spherical particles and how these factors can be tuned to achieve the desired morphology will be shown. Finally, different compositions of Ni-rich NMCs synthesized via same method will be discussed along with their electrochemical performances using a commercial NMC811 as the baseline.Acknowledgement.This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy, through the Advanced Battery Materials Research Program (Battery500 Consortium).