Dry basal plane graphene wrappings on spherical nickel-rich oxide layered particles for lithium-ion batteries

Abstract

Particle-to-particle dry graphene coatings on Ni-rich layered oxide materials are proposed for highenergy lithium-ion batteries (LIBs) to mitigate the inherent and engineering challenges related to the electrochemically fragile surfaces, as well as limiting electrode thickness and density. Utilizing a shear stress-based coating process without supplementary solvent or heat treatment, graphene sheets derived from graphene powder are applied onto the surface of spherical LiNi0.89Co0.055Mn0.055O2 (NCM) material. This process achieves a coating thickness equivalent to or fewer than 10 layers of graphene and exposes the basal plane. The graphene-coated material increases particle hardness and mitigates degradation caused by inter-particle pressure, enabling the formation of high-density electrodes without pulverization. In the absence of additional carbon-conducting agents for the high-density composite electrode with a density of 4.0 g cm 3 , it significantly enhances rate capability, demonstrating more than 5 times improvement by achieving 149.4 mAh g 1 at 2 C compared to the bare sample (28.9 mAh g 1 ). Furthermore, the dry graphene coating enables the high areal capacity of 6.98 mAh cm 2 . By exposing the basal plane of the graphene coating, the process enhances chemical stability, effectively inhibiting side reactions at the interface and mitigating cycle degradation. (c) 2025 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.