A solid-state lubricant composition is disclosed. The solid-lubricant contains graphene, an oxide of a metal, and one or more polymeric binders. A method of making a solid-state lubricant coating on various substrates is disclosed. The method includes the steps of making a homogeneous slurry comprising powder of an oxide of a metal, graphene, and a polymeric binder with organic volatile solvent; coating a substrate with the homogeneous slurry with desired thicknesses; and drying the slurry on the substrate naturally or applying additional heat, resulting in a solid lubricant coating on the substrate. Substrates with coated solid composite lubricant show wear reduction and lower coefficient of friction compared with uncoated substrates.