Enhancing NCM111 Cathode Performance with Sustainable Al2O3 Coating via Ethanol-Based Wet-Chemical Synthesis
Gints Kucinskis
University of Latvia
LiNixCoyMn1-x-yO2 (NCM) cathodes, especially those with high nickel content, are critical for advancing the energy density of lithium-ion batteries yet face significant challenges in maintaining good cycle life. In this study, we introduce a sustainable ethanol-based wet-chemical method to coat NCM111 cathodes with a thin layer of Al2O3, aimed at mitigating surface degradation mechanisms. Beyond studying the coating itself, our study also emphasizes the importance of isolating the benefits of the protective coating from those of re-sintering and surface contaminant removal.
The effects that washing, sintering, and coating have on the electrochemical performance of NCM111 were systematically evaluated. The Al2O3-coated NCM111 demonstrated a substantial improvement in cycling stability, retaining 88% of its initial capacity after 500 charge-discharge cycles, compared to 79% for re-sintered and 65% for untreated samples. While sintering alone enhances cycle life by regenerating the material and eliminating residual lithium compounds on the particle surface, the Al2O3 coating further augments the electrochemical performance, most likely by helping to maintain the layered structure and inhibiting adverse reactions with the electrolyte.
This study presents a cost-effective, environmentally friendly approach to extend the cycle life of NCM cathodes. This method, combined with doping and microstructural modifications, could significantly advance the cycle life of next-generation lithium-ion batteries, especially when applied on high Ni-content NCM materials.