Method for separating positive-pole active substance and method for recovering valuable metals from lithium ion battery
The present invention aims at improving a recovery rate of a positive-pole active substance and preventing a recovery loss of valuable metals when a positive-pole active substance is separated from a lithium ion battery. In the present invention, a material resulting from battery dismantling obtained by dismantling a lithium ion battery is stirred using a surfactant solution, whereby a positive-pole active substance is separated from a positive-electrode substrate. Also, it is preferable that an alkaline solution is added to a positive-electrode material of a material resulting from battery dismantling, thereby dissolving a positive-electrode substrate to which a positive-pole active substance adheres to obtain a slurry containing the positive-pole active substance, and a surfactant solution is added to the slurry to disperse the positive-pole active substance in the slurry, whereby the positive-pole active substance is separated from the alkaline solution.
1. A method for separating a positive-pole active substance from a positive-electrode substrate, the method comprising:
forming a slurry containing the positive-pole active substance by at least (i) adding an alkaline solution to a positive-electrode material including the positive-pole active substance adhered to the positive-electrode substrate, the positive-electrode material obtained from material resulting from dismantling a lithium ion battery, and (ii) dissolving the positive-electrode substrate in the alkaline solution; and
separating the positive-pole active substance from the alkaline solution by at least adding a surfactant solution to the slurry, and stirring the slurry to disperse the positive-pole active substance in the slurry.
2. The method for separating the positive-pole active substance according to claim 1 , wherein the alkaline solution has a concentration of 0.3 to 1.0 N.
3. The method for separating the positive-pole active substance according to claim 1 , wherein, during separating, a stirring medium is added to the slurry to which the surfactant solution is added, and stirred.
4. The method for separating the positive-pole active substance according to claim 1 , wherein the surfactant solution has a concentration of 0.1 to 10% by weight.
5. The method for separating the positive-pole active substance according to claim 1 , wherein the surfactant is a nonionic surfactant having a polyoxyalkylene ether group.
6. The method for separating the positive-pole active substance according to claim 1 , wherein a time of the stirring is not less than 1 hour.
7. A method for recovering valuable metals including separating a positive-pole active substance from a positive-electrode substrate, the method comprising:
forming a slurry containing the positive-pole active substance by at least (i) adding an alkaline solution to a positive-electrode material including the positive-pole active substance adhered to the positive-electrode substrate, the positive-electrode material obtained from material resulting from dismantling a lithium ion battery, and (ii) dissolving the positive-electrode substrate in the alkaline solution; and
separating the positive-pole active substance from the alkaline solution by at least adding a surfactant solution to the slurry to disperse the positive-pole active substance in the slurry.