A black zirconia cathode coating layer enabling facile charge diffusion and surface lattice stabilization for lithium-ion batteries

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 12; no. 44; pp. 30667 - 30675
• Main Authors: Choi, Yoo Jung, Jang, Sungbin, Chang, Hongjun, Kim, Youjin, Kim, Suji, Kim, Ga Yoon, Lee, Juho, Moon, Janghyuk, Kim, Jinsoo, Ryu, Won-Hee
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 12.11.2024
• Subjects: Cathodes; Charge materials; Charge transfer; Coatings; Density functional theory; Diffusion coating; Diffusion layers; Electrical conductivity; Electrical resistivity; Electrochemical analysis; Electrochemistry; Electrode materials; Gas evolution; Hybridization; Insulation; Lithium; Lithium-ion batteries; Oxygen; Protective coatings; Shearing; Surface stability; Zirconia; Zirconium dioxide
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/D4TA05179C

The conformal surface coating of Ni-rich layered cathode materials is essential for mitigating their interfacial and subsequent structural degradation. The zirconia (ZrO 2 ) coating effectively enhances the surface stability of the cathode owing to its excellent chemical durability; however, the insulating electrical conductivity of ZrO 2 increases the electrode resistance and triggers efficiency decay. Here, we propose highly conductive oxygen-deficient black ZrO 2− x as a charge-conductive coating material. The black ZrO 2− x is uniformly coated onto the Ni-rich LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC) surface via a solvent-free mechanochemical shearing process. Benefiting from the black ZrO 2− x coating layer, black ZrO 2− x coated NMC shows improved cycling characteristics and better rate capability than both bare NMC and ZrO 2 coated NMC. The enhanced electrochemical performance by the conformal coating of black ZrO 2− x mainly results from enhanced charge transfer, reduced gas evolution, and mitigated microstructural cracking. Density functional theory calculations confirm that the defective structure of black ZrO 2− x lowers the energy barrier for Li ion transfer, and strong hybridization between Zr in black ZrO 2− x and O in NMC mitigates oxygen evolution.