Highly ordered structure in single-crystalline LiNi_0.65Co_0.15Mn_0.20O₂ with promising Li-ion storage property by precursor pre-oxidation

The crystal structure in Ni-rich layered cathode materials affects the connectivity and dimensionality of stacked atom, accordingly influences Li⁺-ion diffusion kinetics. However, Li⁺/Ni²⁺ cation mixing stubbornly exists on the surface of grains due to the poor chemical durability of nickel element, results in the property degeneration. Herein, an effective strategy controlling oxygen concentration during precursor synthesis process is performed for the preparation of the single-crystalline LiNi_0.65Co_0.15Mn_0.20O₂ materials. Benefiting from the synergistic effect of crystal structure optimization and architecture regulation by pre-oxidation, the electrochemical kinetic is improved by the ordered crystal characteristic, and the structural stability is enhanced by the suppressed internal stress, resulting in the excellent Li⁺-ion storage performance. The remarkable property combined with adequate evidence demonstrates that pre-oxidation strategy can mitigate the cation mixing and enhance the Li⁺-ion transportation, providing a practical strategy for designing Ni-rich layered cathode material with superior Li⁺-ion storage.