Dual-Functional Regulation of Cationic Ordering and Particle Growth in Monodisperse Li-Rich Manganese -Based Oxides Via Kcl-Mediated Molten Salt Calcination

Abstract

Monodisperse lithium-rich manganese-based oxides (MLLOs) synthesized via molten salt calcination are promising cathode materials for high-energy lithium-ion batteries, however, their performance is critically limited by the ambiguous interplay between calcination parameters and structural evolution. Here we report a KCl-mediated molten salt strategy to decouple the synergistic effects of temperature and lithium stoichiometry on cationic ordering and electrochemical performance. It is found that the particle size of monodisperse particles is positively correlated with calcination temperature and lithium source ratio, as the faster migration of Li+ at higher temperatures promotes the epitaxial growth of particles. Conversely, cationic ordering is negatively correlated with both factors, as higher temperatures lead to increased site exchange between Li and Ni, which is detrimental to electrochemical performance. The resulting SCLLO exhibits an initial discharge capacity of up to 262 mAh g-1 at C/10, with an 81% capacity retention after 200 cycles at 1C. This work provides mechanistic insights into the molten salt calcination process and establishes a generalizable paradigm for designing durable single-crystal cathodes.

Keywords: Lithium-rich manganese-based oxides, Monodisperse Particle, Molten salt calcination, Cationic ordering, Particle size