Method for reusing active material by using positive electrode scrap

A method for recycling a positive electrode active material, comprising:

• (a) thermally treating a positive electrode scrap comprising an active material layer on a current collector in air for thermal decomposition of a binder and a conductive material in the active material layer, to separate the current collector from the active material layer, and collecting an active material in the active material layer;
• (b-1) washing the active material collected from the step (a) with a lithium compound solution which is basic in an aqueous solution, and drying;
• (b-2) grinding the active material dried from the step (b-1);
• (b-3) adding a lithium precursor to the active material ground from the step (b-2);
• (c) annealing the active material having the lithium precursor added thereto, to obtain a reusable recycled active material;
• and
• (d) surface-coating the active material annealed from the step (c),
• wherein the active material layer comprises a lithium composite transition metal oxide comprising secondary particles formed by agglomeration of primary particles having a predetermined size, and the grinding step (b-2) comprises reducing the size of the active material dried from the step (b-1) to a particle size that is smaller than the predetermined size and larger than the size of the primary particles, and
• wherein the step (b-3) comprises mixing the active material ground from the step (b-2) with a lithium precursor solution and spray drying to obtain the active material with an adjusted particle size.