Lithium replenishment additive, as a positive electrode additive for lithium-ion batteries, releases abundant active lithium into the battery system during the formation stage, compensating for the loss of active lithium during the first charging process of lithium-ion batteries; Can effectively regulate the first effect of positive and negative electrode materials in the matching battery system, significantly improving the energy density of lithium-ion batteries; Significantly improve the cycling performance of lithium-ion batteries; It can also improve the dynamic performance of lithium-ion batteries, such as reducing DCR and enhancing energy efficiency.