Method for reusing active material by using positive electrode scrap

A method of reusing a positive electrode active material, comprising:

• thermally treating a positive electrode scrap comprising a lithium cobalt oxide positive electrode active material layer, which includes an active material, disposed on a current collector in air at 300 to 650° C. for thermal decomposition of a binder and a conductive material in the active material layer, wherein the positive electrode scrap is collected after punching a positive electrode plate in a positive electrode comprising the lithium cobalt oxide positive electrode active material layer on the current collector;
• separating the current collector from the active material layer,
• collecting the active material in the active material layer;
• washing the active material with a lithium compound solution and drying,
• wherein the lithium compound solution is basic in an aqueous solution and contains a lithium compound in an amount of more than 0% and 15% or less, and
• annealing washed and dried active material in air at 400 to 1000° C. with an addition of at least one lithium precursor of LiOH, Li2CO3, LiNO3 or Li2O, and Co3O4 produced on the surface of the active material during the thermally treating is removed by the annealing.

A method of reusing a positive electrode active material, comprising:

• thermally treating a positive electrode scrap comprising a lithium cobalt oxide positive electrode active material layer, which includes an active material, disposed on a current collector in air for thermal decomposition of a binder and a conductive material in the active material layer,
• separating the current collector from the active material layer,
• collecting the active material in the active material layer;
• washing the active material with a lithium compound solution which is basic in an aqueous solution;
• drying the active material;
• and
• annealing washed and dried active material with an addition of a lithium precursor to obtain a reusable active material,
• wherein the lithium precursor includes Li2CO3, LiNO3 or Li2O, and
• Co3O4 produced on the surface of the active material during the thermally treating is removed by the annealing.