Effect of V2O5 coatings on NMC 111 battery cathode materials in aqueous process

• Published in: Materials chemistry and physics 2025-02, Vol.332, p.130188, Article 130188
• Main Authors: Herrera-Robles, Joel Obed, Azami-Ghadkolai, Milad, Bordia, Rajendra Kumar, Camacho-Montes, Hector, Rodríguez-Gonzalez, Claudia Alejandra, Espinosa-Almeyda, Yoanh, Mani-Gonzalez, Pierre Giovanni
• Format: Article
• Language: English
• Subjects: Aqueous process; Leaching; NMC 111; Sol gel method; V2O5 coating
• ISSN: 0254-0584
• DOI: 10.1016/j.matchemphys.2024.130188

In this study, we focused on the effect of different percentages of V2O5 coating on the chemical stability of NMC 111. Stability and leaching studies were conducted in solutions at varying pH levels to quantify the influence of coating percentage and exposure conditions on chemical stability. Our findings indicate effective protection of NMC 111. The slurries containing coated particles remain stable across acidic, neutral, and basic pH ranges. This observation provides a broad aqueous processing window for coated NMC 111, preventing lithium-ion leaching. For the uncoated samples, the measured pH consistently remained in the basic range, regardless of the initial pH, indicating a strong reaction between NMC 111 and water that leads to the formation of hydroxides. In contrast, for the coated samples, the reaction predominantly involves V2O5. The thicker V2O5 coatings (3% and 4% by weight) are particularly effective in reducing lithium leaching. XRD analysis suggests that the V2O5 coating helps minimize cation mixing. XPS, TEM, and SEM-EDS morphological characterization were performed to confirm the presence of the coating on the surface of the samples. Additionally, the coating percentage and its effect on charge transfer resistance in sintered samples were discussed and analyzed using EIS with Ag as an ion-blocking agent. •Different percentages of coating with V2O5.•Coating reduces cation mix.•Analysis of pH evolution over time at different exposure durations.•Lithium and vanadium leaching in different pH environments.•Charge transfer resistance response at different temperatures.