Crown ether liquid-liquid extraction system for the electrodeposition of lithium metal from brine

Abstract

Electrolytic systems and methods are described for extracting lithium ions from a brine and depositing onto a conductive substrate to form purified lithium and lithium alloys suitable for use in lithium metal batteries. The methods allow for selective extraction of lithium ions and electroplating the extracted lithium ions as lithium metal and lithium metal alloys.

1 . (canceled) 
     
     
         2 . A method for extracting lithium from an aqueous lithium resource, comprising:
 a. transporting lithium ions from the aqueous lithium resource to a non-aqueous electrolyte comprising one or more coordination compounds, wherein the one or more coordination compounds coordinate with the lithium ions;   b. transporting the lithium ions coordinated by the one or more coordination compounds from the non-aqueous electrolyte to a substrate; and   c. electrodepositing lithium metal on the substrate by reducing the lithium ions to the lithium metal.   
     
     
         3 . The method of  claim 2 , wherein the one or more coordination compounds are substantially insoluble in the aqueous lithium resource. 
     
     
         4 . The method of  claim 2 , wherein the non-aqueous electrolyte comprises an organic solvent. 
     
     
         5 . The method of  claim 4 , wherein the organic solvent comprises a molecule comprising one or more carbon-fluorine bonds. 
     
     
         6 . The method of  claim 2 , wherein the non-aqueous electrolyte comprises a lithium salt. 
     
     
         7 . The method of  claim 6 , wherein the lithium salt is substantially insoluble in the organic solvent in the absence of the one or more coordination compounds. 
     
     
         8 . The method of  claim 2 , wherein the one or more coordination compounds selectively coordinate with the lithium ions over non-lithium cations comprising sodium ion, a potassium ion, a magnesium ion, a calcium ion, or a combination thereof. 
     
     
         9 . The method of  claim 2 , wherein the one or more coordination compounds comprise a plurality of ether groups, wherein oxygen atoms of the plurality of ether groups coordinate with the lithium ions. 
     
     
         10 . The method of  claim 9 , wherein the one or more coordination compounds comprise one or more crown ethers. 
     
     
         11 . The method of  claim 2 , wherein the one or more coordination compounds comprise a plurality of amine groups, wherein nitrogen atoms of the plurality of amine groups coordinate with the lithium ions. 
     
     
         12 . The method of  claim 11 , wherein the one or more coordination compounds comprise one or more cryptands. 
     
     
         13 . The method of  claim 2 , wherein the one or more coordination compounds comprise lariat ether, multi-armed ether, calixarene, spherand, cryptaspherand, hemispherand, podand, or a combination thereof. 
     
     
         14 . The method of  claim 2 , wherein the aqueous lithium resource comprises sodium, potassium, magnesium, calcium, boron, chlorine, SO 4   2− , nitrogen, an alkali metal, an alkali earth metal, or any combination thereof. 
     
     
         15 . The method of  claim 14 , wherein a ratio of magnesium to lithium in the aqueous lithium resource is about 0-100 by mass or by mols. 
     
     
         16 . The method of  claim 2 , wherein the aqueous lithium resource is pretreated by dilution, concentration, filtration, nanofiltration, absorption or extraction using organic molecules or inorganic sorbents, electrodialysis using a membrane, concentration and precipitation, solvent extraction, pH adjustment, ion exchange, or any combination thereof. 
     
     
         17 . The method of  claim 16 , wherein the pretreatment removes magnesium or calcium in the aqueous lithium resource. 
     
     
         18 . The method of  claim 2 , wherein the lithium metal comprises less than 0.1 weight % (wt %) or atomic % (at %) of non-conductive impurities. 
     
     
         19 . The method of  claim 2 , wherein the lithium metal comprises less than 0.1 wt % lithium alloys. 
     
     
         20 . The method of  claim 2 , wherein the transporting and the electrodepositing are performed concurrently. 
     
     
         21 . The method of  claim 2 , wherein the transporting and the electrodepositing are performed by applying an electric potential to one or more electrochemical cells, wherein the one or more electrochemical cells comprise or are in contact with the aqueous lithium resource, the non-aqueous electrolyte and the substrate.