Apparatus and Method for Recovering Valuable Substance from Lithium Secondary Battery

Abstract

The present invention includes: a reaction tank ( 1 ) for immersing an electrode material of a lithium secondary battery into a molten salt of lithium chloride containing metal lithium, so as to perform a reducing reaction of the electrode material with the metal lithium; a movable perforated processing vessel ( 10 ) configured to be immersed into the molten salt in the reaction tank ( 1 ) together with the electrode material contained therein; and vessel carrying means for immersing the perforated processing vessel ( 10 ) containing the electrode material therein into the molten salt of lithium chloride in the reaction tank ( 1 ) and pulling up the vessel ( 10 ) from the reaction tank ( 1 ) after a process has been performed. In a vessel wall constituting a vessel main body of the vessel ( 10 ), a plurality of through-holes are formed, such that each through-hole serves to communicate an internal space of the reaction tank ( 1 ) storing the molten salt with an internal space of the vessel main body containing the electrode material.

1 . A recovery apparatus for recovering a valuable substance from a lithium secondary battery, comprising:
 a reaction tank adapted for immersing powder of an electrode material of the lithium secondary battery into a molten salt of lithium chloride containing a metal lithium so as to perform a reducing reaction of the powder of the electrode material with the metal lithium;   a movable perforated processing vessel configured to contain the powder of the electrode material therein and to be immersed into the molten salt of lithium chloride in the reaction tank together with the powder of the electrode material contained therein, the movable perforated processing vessel including a vessel main body in which the powder of the electrode material is filled, wherein a plurality of through-holes, each adapted for communicating an internal space of the reaction tank storing the molten salt of lithium chloride therein with an internal space of the vessel main body containing the powder of the electrode material therein, are formed in a vessel wall constituting the vessel main body, wherein the vessel main body has a thickness of the internal space in which the powder of the electrode material is filled, the thickness being set approximately twice or less than twice a distance that the molten salt of lithium chloride can permeate into the powder of the electrode material filled in the vessel main body, the vessel being filled with a compressed integral mass of the powder of the electrode material of the lithium secondary battery, and   vessel carrying means adapted for immersing the perforated processing vessel containing the powder of the electrode material therein into the molten salt of lithium chloride in the reaction tank and for pulling up the perforated processing vessel from the molten salt of lithium chloride in the reaction tank after a process has been performed.   
     
     
         2 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 1 , wherein the thickness of the internal space of the vessel main body is within a range of approximately  60 mm or less. 
     
     
         3 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 1 , wherein the vessel main body is configured to have the internal space which has a rectangular structure having a rectangular horizontal cross section. 
     
     
         4 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 1 , wherein the vessel main body is configured to have the internal space which has a doughnut-like structure having an annular horizontal cross section. 
     
     
         5 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 1 , wherein each one of the plurality of through-holes has a diameter of approximately 1 mm. 
     
     
         6 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 1 , further comprising a guide tube having a passage formed therein, the passage being used when the perforated processing vessel is immersed into the molten salt of lithium chloride in the reaction tank by the vessel carrying means, the guide tube having a lower end located below a liquid surface of the molten salt of lithium chloride stored in the reaction tank. 
     
     
         7 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 1 , wherein the vessel wall of the vessel main body is fanned from a mesh material or punched metal. 
     
     
         8 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 1 , further comprising electro-deposition means for electrolyzing a lithium oxide produced in the molten salt of lithium chloride in the reaction tank so as to deposit the metal lithium onto a cathode. 
     
     
         9 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 8 , further comprising a lithium electro-deposition tank disposed separately from the reaction tank, the electro-deposition means being located in the lithium electro-deposition tank. 
     
     
         10 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 9 , further comprising a discharging passage including a discharging port located just above a liquid surface of the molten salt of lithium chloride in order to collect the metal lithium accumulated on the liquid surface of the molten salt of lithium chloride in the lithium electro-deposition tank. 
     
     
         11 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 8 , wherein an anode and the cathode of the electro-deposition means are immersed in the molten salt of lithium chloride in the reaction tank. 
     
     
         12 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 11 , wherein a partition member is disposed in the reaction tank, the partition member being adapted for shielding the metal lithium floating on a liquid surface of the molten salt of lithium chloride in the reaction tank from the anode of the electro-deposition means. 
     
     
         13 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 12 , further comprising a discharging passage including a discharging port located just above the liquid surface of the molten salt of lithium chloride in order to collect the metal lithium accumulated on the liquid surface of the molten salt of lithium chloride in the reaction tank. 
     
     
         14 . The recovery apparatus for recovering the valuable substance from the lithium secondary battery according to  claim 1 , further comprising a water tank configured such that the perforated processing vessel is immersed into water in order to remove an extraneous material after the perforated processing vessel has been pulled up from the molten salt of lithium chloride in the reaction tank. 
     
     
         15 . A recovery method of recovering a valuable substance from a lithium secondary battery, comprising:
 an immersing step of immersing a movable perforated processing vessel, which includes a vessel main body filled with a compressed integral mass of powder of an electrode material of the lithium secondary battery, into a molten salt of lithium chloride which is stored in a reaction tank and contains a metal lithium, wherein a plurality of through-holes, each adapted for communicating an internal space of the reaction tank storing the molten salt of lithium chloride therein with an internal space of the vessel main body containing the powder of the electrode material therein, are formed in a vessel wall constituting the vessel main body;   a reducing reaction step of performing a reducing reaction of the powder of the electrode material with the metal lithium in the reaction tank, wherein the molten salt of lithium chloride, in which the metal lithium as a reducing agent and a lithium oxide as a reaction product are dissolved, flows through the plurality of through-holes of the vessel main body, wherein the vessel main body has a thickness of the internal space in which the powder of the electrode material is filled, the thickness being set approximately twice or less than twice a distance that the molten salt of lithium chloride can permeate into the powder of the electrode material filled in the vessel main body, wherein in the reducing reaction step, the molten salt of lithium chloride can permeate into substantially an entirety of the powder of the electrode material filled in the vessel main body; and   a pulling up step of pulling up the perforated processing vessel from the molten salt of lithium chloride in the reaction tank after the reducing reaction step has been performed.   
     
     
         16 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 15 , wherein, in the immersing step and the pulling up step, the perforated processing vessel is immersed into and pulled up from the molten salt of lithium chloride in the reaction tank through an interior of a guide tube, the guide tube having a lower end located below a liquid surface of the molten salt of lithium chloride stored in the reaction tank. 
     
     
         17 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 16 , further comprising a preparation step of supplying the molten salt of lithium chloride and the metal lithium into the reaction tank prior to the immersing step, wherein the molten salt of lithium chloride is first supplied into the reaction tank until a liquid surface thereof reaches a level above the lower end of the guide tube, and the metal lithium is then supplied onto the liquid surface of the molten salt of lithium chloride in the reaction tank outside of the guide tube. 
     
     
         18 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 15 , further comprising an electro-deposition step of electrolyzing a lithium oxide produced in the molten salt of lithium chloride in the reaction tank in the reducing reaction step, so as to deposit the metal lithium onto a cathode. 
     
     
         19 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 18 , wherein the electro-deposition step is carried out by using a pair of electrodes located in a lithium electro-deposition tank which is disposed separately from the reaction tank. 
     
     
         20 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 18 , wherein the electro-deposition step is carried out by using a pair of electrodes disposed in the reaction tank. 
     
     
         21 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 18 , wherein the metal lithium deposited on the cathode and then floating to and accumulated on a liquid surface of the molten salt of lithium chloride is discharged through a discharging passage including a discharging port located just above the liquid surface of the molten salt of lithium chloride. 
     
     
         22 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 15 , further comprising a water washing step of immersing the perforated processing vessel into water so as to remove an extraneous material after the perforated processing vessel has been pulled up from the molten salt of lithium chloride in the reaction tank by the pulling up step. 
     
     
         23 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 15 , further comprising a filling step of filling and compressing the powder of the electrode material of a powdery state into the vessel main body prior to the immersing step. 
     
     
         24 . The recovery method of recovering the valuable substance from the lithium secondary battery according to  claim 15 , wherein, in the reducing reaction step, once the metal lithium is consumed by the reducing reaction with the powder of the electrode material, the metal lithium floating on a liquid surface of the molten salt of lithium chloride stored in the reaction tank will be dissolved and supplied into the molten salt of lithium chloride, so as to keep a chemical equilibrium.