One-Pot Synthesis for Doping and Coating NMC 811 with B, Al, and Nb for Enhanced Stability

Abstract

A promising cathode material is NMC 811 (LiNi_0.8Mn_0.1Co_0.1O₂), but its commercial adoption is hindered by structural and surface degradation, which cause rapid capacity fading. This degradation manifests as cation mixing, microcrack formation, parasitic side reactions arising from HF attack and oxygen release, collectively compromising the material's long-term stability. To address this, we investigated a multi-element strategy using a patented one-pot Metal-to-Cathode Active Material (M2CAM^®) process to simultaneously dope and coat the material with boron, aluminum, and niobium. This approach is designed to synergistically enhance the cathode's stability. Comprehensive material analysis and electrochemical testing (galvanostatic cycling and rate capability) were performed. The results show that NMC 811 doped with B, Al, and Nb achieved a capacity retention of ~91% after 100 cycles at 1C, a significant improvement over the ~76% retention exhibited by the pristine material. This enhancement is attributed to both bulk structural stabilization by the dopants and improved surface integrity provided by a concurrently formed niobium-based coating. This scalable, single-step synthesis offers a viable path to producing durable, high-performance cathodes for demanding applications, such as electric vehicles and grid-scale storage. These findings highlight the effectiveness of multi-component, single-step modifications in overcoming the intrinsic limitations of Ni-rich cathode materials.