Method for recycling positive electrode material
A method for recycling a positive electrode material. the method includes obtaining positive electrode material particles from a positive electrode. The method further includes mixing the positive electrode material particles with a solution or powder containing sodium ions and heat-treating the mixture including the positive electrode material particles and the solution or power containing sodium ions. The method further includes rinsing the heat-treated positive electrode material particles with water.
1 . A method for recycling a positive electrode material, the method comprising:
(S 1 ) obtaining positive electrode material particles from a positive electrode;
(S 2 ) heat-treating the positive electrode material particles that includes mixing the positive electrode material particles with a solution or powder containing sodium ions such that the sodium ions react with fluorine at the positive electrode material particles to form sodium fluoride; and
(S 3 ) rinsing the heat-treated positive electrode material particles with water.
2 . The method of claim 1 , wherein the step (S 1 ) comprises:
(S 1 - 1 ) crushing the positive electrode of a lithium secondary battery into crushed parts; and
(S 1 - 2 ) classifying the crushed parts to separate the positive electrode material particles from current collector particles.
3 . The method of claim 1 , wherein the step (S 1 ) is performed using a chemical solvent immersion method or a heat-treatment method.
4 . The method of claim 1 , wherein the solution or the powder containing sodium ions is alkaline.
5 . The method of claim 1 , wherein the solution or the powder containing sodium ions is prepared using at least one selected from the group consisting of NaOH, Na 2 CO 3 , and NaHCO 3 .
6 . The method of claim 1 , wherein the solution or the powder containing sodium ions has a number of moles of sodium ions that is 150% to 200% greater than a number of moles of the fluorine.
7 . The method of claim 1 , wherein the solution containing sodium ions has a sodium concentration of 0.1 to 10 M.
8 . The method of claim 1 , wherein the heat-treatment is performed in an oxygen-free atmosphere.
9 . The method of claim 8 , wherein the oxygen-free atmosphere is an atmosphere having an oxygen concentration of 3 volume % or less.
10 . The method of claim 8 , wherein the oxygen-free atmosphere is formed by including at least one gas selected from a group comprising of nitrogen, carbon dioxide, and an inert gas.
11 . The method of claim 1 , wherein the heat-treatment is performed in an oxygen enrichment atmosphere.
12 . The method of claim 11 , wherein the oxygen enrichment atmosphere is an atmosphere having an oxygen concentration of 20 volume % or greater.
13 . The method of claim 1 , wherein the heat-treatment is performed at 250 to 800° C.
14 . The method of claim 3 , wherein the chemical solvent comprises methylpyrrolidone (NMP) or dimethylacetamide (DMAC).