Synergistic LiBO2/CeF3 hybrid coating engineering for chemically stabilized cathode–electrolyte interphase in nickel-rich cathodes

Abstract

Nickel-rich LiNi_xCo_yMn_1−x−yO₂ (NCM) cathodes, pivotal for high-energy–density lithium-ion batteries, face severe challenges from surface residual lithium compounds and hydrofluoric acid (HF)-induced degradation. These issues accelerate capacity fading, exacerbate interfacial polarization, and compromise safety. To address these issues, we proposed a scalable CeF₃/H₃BO₃ hybrid coating strategy for LiNi_0.82Co_0.12Mn_0.06O₂ cathodes. The CeF₃ nanoparticles served as a robust physical barrier, effectively scavenging HF, while the LiBO₂ layer derived from H₃BO₃ eliminated residual Li₂CO₃ through chemical conversion and established rapid Li⁺ transport pathways. Dynamic B-O bond reorganization enabled self-repair of coating defects, synergistically suppressing interfacial polarization and maintaining structural integrity. Electrochemical evaluations demonstrated that the hybrid-coated cathode achieves 94% capacity retention after 200 cycles at 1C (2.8–4.3 V), significantly outperforming the pristine NCM (56.3%). Additionally, the modified cathode exhibits enhanced air stability, with suppressed H₂O/CO₂ infiltration, and delivers 80% capacity retention after 1000 cycles in practical pouch cells. This work provides a cost-effective and industrially viable solution to simultaneously mitigate HF corrosion, residual lithium accumulation, and cathode–electrolyte interphase instability, paving the way for durable high-energy–density batteries.

Graphical abstract