Abstract: Disclosed herein are methods, systems, and compositions for the liquid-phase deposition of film coatings onto the surface of battery material powders. The battery material powders are introduced into a reaction vessel within which the coating is to be performed. A solvent is added to the reaction vessel to fluidize the battery material powders, thereby yielding a slurry composed of the solvent and powders. A first reagent is then added into the reaction vessel to react with the slurry to produce battery material powders comprising an adsorbed partial layer of the first reagent. A second reagent is added into reaction vessel to react with the battery material powders comprising an adsorbed monolayer of first reagent, thereby yielding coated battery material powders comprising at least one monolayer film.