Lithium-supplementing additive, preparation method and application thereof

A lithium-supplementing additive, a preparation method therefor and application thereof. The lithium-supplementing additive includes a core body and a functional encapsulation layer coated on the core body, and the core body includes a lithium-supplementing material. Lithium carbonate is dispersed in the interface between the functional encapsulation layer and the core body or/and in the functional encapsulation layer. In the lithium-supplementing additive of the present application, the lithium carbonate dispersed in the interface between the functional encapsulation layer and the core body or/and in the functional encapsulation layer has a synergistic effect with the functional encapsulation layer, and can effectively improve the effect of the functional encapsulation layer on the core body, so that the core body is isolated from ambient moisture and COto ensure the stability of the core body, thereby ensuring the effect and stability of lithium supplementation of the lithium-supplementing additive.