Enhanced cycling stability of nickel-rich single-crystal LiNi0.83Co0.12Mn0.05O2 at high voltage via low-temperature epitaxial rock-salt interface engineering

Abstract

To improve the cycling stability of nickel-rich single-crystal LiNi_0.83Co_0.12Mn_0.05O₂ under high operating voltage while avoiding the impact on the main structure caused by conventional secondary calcination modification methods, a rock-salt phase interface layer (< 10 nm) is constructed on the surface of LiNi_0.83Co_0.12Mn_0.05O₂ through low-temperature epitaxial self-growth without introducing heterogeneous atoms. In situ X-ray diffraction (XRD) analysis reveals the formation of a metastable transition phase during the deep delithiation process. Notably, the presence of the rock-salt phase layer remarkably suppresses the persistence of the metastable transition phase. Further investigation using differential capacitance curve (dQ/dV) demonstrates that suppressing this metastable phase improves the reversibility of the H2–H3 phase transition, thus facilitating long-term cycling stability of the modified sample at 4.5 V. This work presents a novel and effective interface reconstruction approach for the modification of single-crystal nickel-rich cathodes.

Graphical Abstract