Method and system for separating cathode material of waste lithium secondary battery using oxidation reaction of anode material and reduction reaction of cathode material

A method of separating a cathode material of a waste lithium secondary battery using an oxidation reaction of an anode material and a reduction reaction of the cathode material, the method recovering cathode active materials (Co, Ni, and Mn) from black powder in which raw materials (Co, Ni, Mn, Li, and C) for the cathode and anode materials are mixed, the method comprising:

• introducing a waste lithium secondary battery scrap into a low-temperature pyrolysis furnace (110) of a low-temperature pyrolysis system (100):
• and
• extracting the black powder and a current collector mixture (Cu and Al) by causing an explosive reaction of lithium contained in a waste lithium secondary battery scrap,
• wherein the cathode material is reduced through an oxidation-reduction reaction between the cathode material and the anode material in the black powder so that the cathode active materials (Co, Ni, and Mn) recover magnetism (or ferromagnetism), after which a magnetic separation process is performed to separate the black powder into the cathode active materials (Co, Ni, and Mn) moved in the direction of a magnetic force and an anode active material (C) moved in the opposite direction of the magnetic force.

A system for separating a cathode material of a waste lithium secondary battery using an oxidation reaction of an anode material and a reduction reaction of the cathode material, the system recovering cathode active materials (Co, Ni, and Mn) from black powder in which raw materials (Co, Ni, Mn, Li, and C) for the cathode and anode materials are mixed, the system comprising:

• a low-temperature pyrolysis furnace (110) rotatably supported on a base frame (1), and configured to heat and gasify a binder, an electrolyte, and a separator, which are organic compounds contained in a waste lithium secondary battery scrap, inside the low-temperature pyrolysis furnace (110) into syngas, remove the resulting syngas, and extract the black powder and a current collector mixture (Cu and Al), the low-temperature pyrolysis furnace having an annular flange (F) extended at each of front and rear ends thereof, an inlet (112) formed at the front end thereof and into which the waste lithium secondary battery scrap is introduced, and a closed space (113) formed therein;
• a low-temperature pyrolysis furnace rotation module (120) configured to rotate the low-temperature pyrolysis furnace (110) in a predetermined direction or in the opposite direction;
• an electric heating device (130) fixedly installed on the base frame (1) to surround an outside of the low-temperature pyrolysis furnace (110), and configured to heat the low-temperature pyrolysis furnace (110);
• a spiral (140) installed inside the low-temperature pyrolysis furnace (110), and configured to stir the waste lithium secondary battery scrap and the black powder and to promote the reduction reaction of the cathode material and the oxidation reaction of the anode material;
• a bucket (150) fixedly installed on an inner wall of the low-temperature pyrolysis furnace (110) and configured to extract the black powder and the current collector mixture;
• a screw conveyor (160) installed horizontally at the rear end of the low-temperature pyrolysis furnace (110), with an end being inserted into the low-temperature pyrolysis furnace (110), and configured to transfer the black powder and the current collector mixture;
• a syngas storage tank (170) connected to the screw conveyor (160) and a syngas discharge connection pipe (171) and configured to store the syngas discharged from the low-temperature pyrolysis furnace (110);
• a main hopper (180) configured to store the black powder and the current collector mixture extracted by the low-temperature pyrolysis furnace (110);
• and
• a magnetic separator (190) configured to separate the black powder into the cathode active materials (Co, Ni, and Mn) moved in the direction of a magnetic force and an anode active material (C) moved in the opposite direction of the magnetic force.

A system for separating a cathode material of a waste lithium secondary battery using an oxidation reaction of an anode material and a reduction reaction of the cathode material, the system recovering cathode active materials (Co, Ni, and Mn) from black powder in which raw materials (Co, Ni, Mn, Li, and C) for the cathode and anode materials are mixed, the system comprising:

• a low-temperature pyrolysis furnace (110) having an inlet (112) into which a waste lithium secondary battery scrap is introduced, and a closed space (113) formed therein;
• an electric heating device (130) installed on an outside of the low-temperature pyrolysis furnace (110), and configured to heat the low-temperature pyrolysis furnace (110);
• a screw conveyor (160) installed at a rear end of the low-temperature pyrolysis furnace (110) and configured to transfer the black powder and the current collector mixture;
• and
• a magnetic separator (190) configured to separate the black powder into the cathode active materials (Co, Ni, and Mn) moved in the direction of a magnetic force and an anode active material (C) moved in the opposite direction of the magnetic force.