Method for recovering positive electrode active material from lithium secondary battery
The present invention relates to a method for recovering a positive electrode active material from a lithium secondary battery including: 1) separating a positive electrode into a collector and a positive electrode part; 2) removing an organic substance by firing the separated positive electrode part; 3) washing the fired resultant and removing remaining fluorine (F); 4) adding a lithium-containing material into the washed resultant and firing to recover a lithium transition metal oxide.
1. A method for recovering a positive electrode active material from a lithium secondary battery, the method comprising:
1) separating a positive electrode into a collector and a positive electrode part;
2) removing an organic substance by firing the separated positive electrode part;
3) washing the fired resultant and removing residual fluorine (F); and
4) adding a lithium-containing material into the washed resultant and firing to reform a lithium transition metal oxide,
wherein the washing of step 3) is performed by using pure water.
2. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the firing of step 2) is performed at a temperature of 300-1,200° C.
3. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the firing of step 2) is performed for 20-600 minutes.
4. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , further comprising pulverizing the separated positive electrode part prior to the firing of step 2).
5. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the organic substance comprises a fluorine(F)-containing material.
6. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the washing of step 3) is performed at a temperature of 0-100° C.
7. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the washing of step 3) is performed for 1-600 minutes.
8. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the washing of step 3) is performed by using 50-100,000 parts by weight of washing solution with respect to 100 parts by weight of the resultant.
9. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein in step 4), 1-40 parts by weight of a lithium-containing raw material is added with respect to 100 parts by weight of the resultant.
10. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the firing of step 4) is performed at a temperature of 500-1,200° C.
11. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the lithium transition metal oxide is represented by formula 1 below:
Li a Ni x Mn y Co z M w O 2+δ [Formula 1]
(In formula 1, M includes one or more selected from the group consisting or Fe, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga and B, and 0.9<a≤2.0, 0≤x≤0.95, 0≤y≤0.8, 0≤z≤1.0, 0<w≤0.1, −0.02≤δ≤0.02, x+y+z≤1).
12. The method for recovering a positive electrode active material from a lithium secondary battery of claim 1 , wherein the recovered positive electrode active material has a content of fluorine (F) of less than 1 wt %.