LiNbO coating on Mg-doped NCM-622 cathode—a dual modification to enhance the electrochemical performance at higher voltage for lithium-ion batteries

Ni-rich cathodes are very attractive in terms of high-energy density cathodes. However, it still suffers from various disadvantages, making commercialization more difficult. A dual-modifying cathode is a simple and efficient strategy that can have a synergistic effect of surface coating on the outside, and doping can have internal structure stabilization. CSTR-level doping of Mg can significantly extend the battery’s cycle life due to its pillar effect, and LiNbO is a prominent coating material with high ionic conductivity. The dual-modified cathode in this study has shown excellent electrochemical performance in terms of cyclic stability and rate performance, even at 4.5 V vs. Li. The modified cathode showed 85.4% capacity retention at 4.3 V and 87.11% at 4.5 V, whereas the bare showed only 78.9% and 68.2%, respectively. The LiNbO-coating protects the material from the surface side reactions from the electrolytes at high voltage operations, and the “pillar effect” due to Mg doping stabilizes the structure for longer cycles and higher C-rates, making this dually modified cathode a prominent cathode material for lithium-ion batteries. Graphical abstract: (Figure presented.)