Selective recovery device for lithium using flow electrode capacitive deionization and method for separating and recovering lithium using the same

Abstract

The present disclosure relates to a device for selectively recovering lithium using flow electrode capacitive deionization, and a method for separating and recovering lithium using the same. The device for selectively recovering lithium and the method for separating and recovering lithium according to the present disclosure have very high selectivity for lithium ions (Li + ) such that lithium ions (Li + ) can be selectively separated from a mixture including various ions, and the lithium recovery rate and lithium recovery efficiency are very excellent such that the lithium recovery time and cost are reduced, energy consumption is low, and lithium ions (Li + ) can be recovered from the waste liquid of a spent battery, and thus, it is environmentally friendly.

What is claimed is: 
     
         1 . A selective lithium recovery device using flow electrode capacitive deionization with enhanced selectivity for lithium ions (Li + ), the selective recovery device comprising a selective ion recovery cell, comprising:
 an electrolyte chamber in which an electrolyte solution containing lithium ions (Li + ) and polyvalent cations is supplied;   an anode and a cathode arranged with the electrolyte chamber therebetween;   a cation exchange membrane (CEM) arranged between the electrolyte chamber and the anode; and   an anion exchange membrane (AEM) arranged between the electrolyte chamber and the cathode,   wherein the anode is a flow electrode and comprises a current collector for anode and an anode active material,   wherein the cathode is a flow electrode and comprises a current collector for cathode and a cathode active material, and   wherein at least one of the cation exchange membrane and the anion exchange membrane is bonded with a polymer thin film layer.   
     
     
         2 . The selective recovery device of  claim 1 , wherein the polyvalent cations comprise cobalt ions (Co 2+ ) and/or nickel ions (Ni 2+ ). 
     
     
         3 . The selective recovery device of  claim 1 , wherein the polymer thin film layer is composed of multiple layers,
 wherein the multilayer polymer thin film layer is composed of a first polymer electrolyte layer and a second polymer electrolyte layer that are alternately laminated, and   wherein the first polymer electrolyte layer and the second polymer electrolyte layer are configured to have opposite polarities.   
     
     
         4 . The selective recovery device of  claim 3 , wherein the multilayer polymer thin film layer is bonded to the cation exchange membrane and is arranged between the cation exchange membrane and the electrolyte chamber,
 wherein the first polymer electrolyte layer is configured to have a positive charge, and   wherein the second polymer electrolyte layer is configured to have a negative charge.   
     
     
         5 . The selective recovery device of  claim 4 , wherein the first polymer electrolyte layer comprises poly(allylamine hydrochloride) (PAH), and
 wherein the second polymer electrolyte layer comprises poly(styrene sulfonate) (PSS).   
     
     
         6 . The selective recovery device of  claim 4 , wherein the multilayer polymer thin film layer has the first polymer electrolyte layer formed on the outermost surface of surfaces bonded to the cation exchange membrane. 
     
     
         7 . The selective recovery device of  claim 3 , wherein the multilayer polymer thin film layer is 3 to 8 layers. 
     
     
         8 . The selective recovery device of  claim 1 , wherein the anode active material is disposed between the anode current collector and the cation exchange membrane,
 wherein the cathode active material is disposed between the cathode current collector and the anion exchange membrane, and   wherein the anode active material and the cathode active material are porous activated carbon solutions.   
     
     
         9 . The selective recovery device of  claim 1 , wherein the ion selectivity 
       
         
           
             
               ( 
               
                 ρ 
                 D 
                 
                   Li 
                   + 
                 
               
               ) 
             
           
         
       
       value for lithium ions (Li+) calculated by Formula 1 below is 10 or more: 
       
         
           
             
               
                 
                   
                     
                       ρ 
                       D 
                       
                         Li 
                         + 
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             
                               C 
                               
                                 Li 
                                 + 
                               
                               0 
                             
                             - 
                             
                               C 
                               
                                 Li 
                                 + 
                               
                             
                           
                           
                             C 
                             
                               Li 
                               + 
                             
                             0 
                           
                         
                         ) 
                       
                       / 
                       
                         ( 
                         
                           
                             
                               C 
                               D 
                               0 
                             
                             - 
                             
                               C 
                               D 
                             
                           
                           
                             C 
                             D 
                             0 
                           
                         
                         ) 
                       
                     
                   
                 
                 
                   
                     < 
                     
                       Formula 
                       ⁢ 
                           
                       1 
                     
                     > 
                   
                 
               
             
           
         
         wherein in Formula 1, 
       
       
         
           
             
               
                 C 
                 
                   Li 
                   + 
                 
                 0 
               
               ⁢ 
                   
               and 
               ⁢ 
                   
               
                 C 
                 D 
                 0 
               
             
           
         
       
       are an initial lithium ion (Li + ) concentration and a polyvalent cation concentration in an influent, respectively, and C Li     +    and C D  are a lithium ion (Li + ) concentration and a polyvalent cation concentration in treated water subjected to selective ion separation, respectively. 
     
     
         10 . A method for separating and recovering lithium, by introducing an electrolyte solution containing lithium ions (Li + ) and polyvalent cations into an electrolyte chamber of the selective recovery device of  claim 1  and applying a voltage. 
     
     
         11 . The method of  claim 10 , wherein the voltage is 0.2 to 0.8 V and the pH of the electrolyte solution is 4 to 7, or the voltage is 0.8 to 1.6 V and the pH of the electrolyte solution is 1 to 4. 
     
     
         12 . The method of  claim 10 , wherein the flow rate of the electrolyte solution is 1.2 mL/min or more, and
 wherein the initial ion concentration of lithium in the electrolyte solution is 5 mM or more.