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

Herein, we propose coating Ni-rich layered oxide materials with particle-to-particle dry graphene for the use in lithium-ion batteries. This method also alleviates the inherent difficulties associated with electrochemically fragile surfaces. Particle-to-particle dry graphene coatings on Ni-rich layered oxide materials are proposed for high-energy 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 LiNi 0.89 Co 0.055 Mn 0.055 O 2 (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.