How Does the Precursor Influence the Li-Rich Layered Oxide Cathode?

Abstract

As a fundamental determinant of Li-ion battery (LIB) cathode performance and production scalability/feasibility, selection and optimization of precursors represent an essential challenge for the commercialization of layered oxide cathodes. However, for lithium-rich layered oxide (LRLO) cathodes, the overwhelming majority of laboratory research has rigidly continued to employ carbonate precursors for further modifications while ignoring the potential of hydroxide precursors, which have been undisputedly utilized as commercial precursors for large-scale production of nickel-cobalt-manganese oxide (NCM) cathodes. This bias toward precursor selection seriously impedes the practical application of the LRLO cathode and largely wastes the resources of lab-scale scientific research. Herein, through comparative analysis, the structure-property relationship between carbonate precursor-derived (CO3-) and hydroxide precursor-derived (OH-) LRLO cathodes was established, elucidating the significance of particle architectural features, especially primary-particle stacking density (PSD). Specifically, the lower PSD of the CO3-LRLO cathode facilitates Li⁺ diffusion by enriching the electrolyte-infiltrated ionic transport pathway but introduces cracks that reduce the volumetric energy density and interfacial/thermal stability. In contrast, the higher PSD of the OH-LRLO cathode improves structural integrity by enhancing the covalent environment, layered structure, and particle architecture. Moreover, multiple optimization approaches have been proposed and implemented (e.g., electrolyte engineering, lattice doping, and blending strategies) to mitigate inherent drawbacks derived from various precursors.

Keywords: Anionic redox; Lithium‐rich cathode; Precursor; Primary‐particle stacking density; Structure distortion.