Method and electrochemical device for low environmental impact lithium recovery from aqueous solutions

Abstract

An efficient and low environmental impact method is disclosed for the recovery of lithium from aqueous solution, for example, brines from high altitude salt lakes. The method comprises the use of an electrochemical reactor with electrodes which are highly selective for lithium, where lithium ions are inserted in the crystal structure of manganese oxide in the cathode, and extracted from the crystal structure of manganese oxide in the anode. Also disclosed are three-dimensional carbon electrodes embedded in manganese oxides formed by impregnating a porous support, for example a carbon felt, with a manganese oxide/carbon black slurry.

1 . A packed bed electrochemical cell for extracting lithium from an aqueous solution containing lithium ions comprising:
 (a) a first electrode comprising a compartment packed with a high surface carbon substrate coated with a lithium insertion compound comprising LiMn 2 O 4 ,   (b) a second electrode comprising a compartment packed with a high surface carbon substrate coated with a chloride reversible electrode material; and   (c) a non-membranous porous material interposed between the first and second electrode,   wherein the high surface carbon substrate comprises calcined coke carbon particles.   
     
     
         2 . The packed bed electrochemical cell according to  claim 1 , wherein the calcined coke carbon particles are calcined petroleum coke carbon particles. 
     
     
         3 . The packed bed electrochemical cell according to  claim 1 , wherein the chloride reversible electrode material comprises polypyrrole. 
     
     
         4 . The packed bed electrochemical cell according to  claim 1 , wherein the non-membranous porous material separating the first and second electrode comprises a porous fritted glass separator. 
     
     
         5 . The packed bed electrochemical cell according to  claim 1 , further comprising current collection contacts which are in contact with the electrodes. 
     
     
         6 . The packed bed electrochemical cell according to  claim 5 , where the current collection contacts are titanium mesh current collectors. 
     
     
         7 - 32 . (canceled) 
     
     
         33 . An electrochemical device for extracting lithium from an aqueous solution containing lithium ions comprising at least one battery-type electrode comprising a porous or high surface substrate coated with a lithium insertion compound, wherein said device does not comprise a counter-electrode. 
     
     
         34 . The electrochemical device according to  claim 33 , wherein the device further comprises a chloride or polypyrrole reversible electrode. 
     
     
         35 . The electrochemical device according to  claim 33 , wherein the substrate is a carbon substrate. 
     
     
         36 . The electrochemical device according to  claim 35 , wherein the carbon substrate is a conductive substrate. 
     
     
         37 . The electrochemical device according to  claim 33 , wherein the battery-type electrode comprises a conductive additive material. 
     
     
         38 . The electrochemical device according to  claim 37 , wherein the conductive additive material is carbon black. 
     
     
         39 . The electrochemical device according to  claim 33 , wherein the lithium insertion compound comprises a manganese oxide. 
     
     
         40 . The electrochemical device according to  claim 39 , wherein the manganese oxide comprises γ-MnO 2  and/or λ-MnO 2 . 
     
     
         41 . The electrochemical device according to  claim 39 , wherein the manganese oxide has a spinel crystal structure. 
     
     
         42 . The electrochemical device according to  claim 39 , wherein the manganese oxide comprises LiMn 2 O 4 . 
     
     
         43 . The electrochemical device according to  claim 33 , wherein the lithium insertion compound comprises lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide, or combinations thereof. 
     
     
         44 . The electrochemical device according to  claim 43 , wherein the lithium cobalt oxide comprises LiCoO 2 . 
     
     
         45 . The electrochemical device according to  claim 43 , wherein the lithium iron phosphate comprises LiFePO 4 . 
     
     
         46 . The electrochemical device according to  claim 33 , wherein the battery-type electrode is prepared by electrolytical delithiation of a porous or high surface substrate coated with lithium cobalt oxide (LiCoO 2 ), lithium iron phosphate (LiFePO 4 ), lithium manganese oxide (LiMn 2 O 4 ), or combinations thereof. 
     
     
         47 . The electrochemical device according to  claim 33 , wherein the carbon substrate is selected from the group consisting of carbon felt, carbon cloth, carbon paper, graphite granules, granite foam, high surface area graphite fiber, and combinations thereof. 
     
     
         48 . The electrochemical device according to  claim 33 , wherein the carbon substrate is a carbon felt. 
     
     
         49 . The electrochemical device according to  claim 34 , wherein the chloride reversible electrode comprises a porous or high surface carbon substrate and silver metal particles. 
     
     
         50 . The electrochemical device according to  claim 49 , wherein the silver metal particles are nanoparticles. 
     
     
         51 . The electrochemical device according to  claim 34 , wherein the chloride reversible electrode further comprises an electrically conductive polymer. 
     
     
         52 . The electrochemical device according to  claim 51 , wherein the electrically conductive polymer is a polypyrrole. 
     
     
         53 . The electrochemical device according to  claim 33 , wherein the lithium ions in the aqueous solution are captured by insertion in the crystal structure of the battery-type electrode. 
     
     
         54 . The electrochemical device according to  claim 34 , wherein the battery-type electrode and chloride reversible electrode are positioned in separate half-cells. 
     
     
         55 . The electrochemical device according to  claim 54 , wherein the half-cell comprising the battery-type electrode and the half-cell comprising the chloride reversible electrode are separated by a semi-permeable electrolysis membrane. 
     
     
         56 . The electrochemical device according to  claim 55 , wherein the electrolysis membrane is an ionomer membrane. 
     
     
         57 . The electrochemical device according to  claim 56 , wherein the ionomer membrane is a N AFION ® membrane. 
     
     
         58 . The electrochemical device according to  claim 57 , wherein the N AFION ® membrane is N AFION ® 324. 
     
     
         59 - 67 . (canceled)