PARTICULES COMPOSITES DE GRAPHITE ET DE GROUPE IVA ET PROCÉDÉS DE FABRICATION

摘要

The present invention provides micron or submicron particles (NPs) that are comprised of a variety of materials, including Group IVA elements such as silicon (Si) that are known to have a high electrochemical capacity in Li-ion secondary batteries. The micron or sub-micron particles of the invention are provided with a surface layer, or surface modification, that imparts additional functionality to the particle. Surface modification prevents the formation of a dielectric oxide layer on the primary Group IV A particles, allowing elements of the surface modifier to covalently bond directly to the Group IV A elements, accommodates volumetric expansion to help mitigate ingress of electrolyte solvents from penetrating the surface modifier, mitigates disruption of SEI layers formed during electrochemical cycling and provides favorable surface properties to allow the formation of strong bonding to binders and other materials in the electrode composite. The NPs can be combined with graphite particles to create a composite graphite particle that can be used for battery anodes.