The energy density as well as the cost of lithium ion batteries (LIBs) strongly depend on the cathode active materials (CAMs) and further improvements are needed to enable an extensive mass-market penetration of electric vehicles in the coming years. On the one hand, by increasing the Nickel content in the technologically most mature class of cathode materials, Ni-rich NCM-type layered oxide materials (LiNi1−x−yCoxMnyO2), the discharge capacity and therefore the energy density on material level can be gradually increased. Furthermore, the decrease of the Cobalt content as the most critical raw material will also have a significant impact on the production costs of the CAMs. However, Ni-rich layered oxides (Ni content > 80 mol.%) face several challenges upon cycling, including severe capacity fading and safety issues that need to be overcome before commercialization. [1] One of the most promising approaches to improve the capacity retention of Ni-rich NCM-type layered oxide cathode materials consists of the design of advanced particle morphologies e.g. core-shell (CS) particles and concentration gradient particles going from a Ni-rich core providing high capacities to a Mn-richer shell that stabilizes the electrode | electrolyte interphase, and minimizes capacity fading and safety issues. [2] In this work, the synthesis of core-shell Ni-rich NCM CAMs particles in a continuously Couette‐Taylor Flow Reactor (CTFR) is thoroughly evaluated, with a special focus on the impact of different synthesis conditions on the electrochemical performance. The CTFR is a novel technology that allows for a very homogeneous micro-mixing of reactants with higher mixing intensity, shorter processing times, and design of highly uniform spherical particles with high tap density and narrow size distribution. Herein, the hydroxide cathode precursor is first co-precipitated using a CTFR reactor and the impact of different co-precipitation conditions on particle morphology and crystallinity is evaluated (e.g. core:shell ratio, overall stoichiometry and lithiation temperature). The electrochemical performance of these materials in NMC||Li and NMC||graphite full cells is then evaluated in dependence of the synthesis conditions.

[1] W. Li, E.M. Erickson, A. Manthiram, High-nickel layered oxide cathodes for lithium-based automotive batteries, Nature Energy, 5 (2020) 26-34.
[2] K.H. Choi, X. Liu, X. Ding, Q. Li, Design strategies for development of nickel-rich ternary lithium-ion battery, Ionics, 26 (2020) 1063-1080.