Producing lithium

Abstract

A electrolytic process for continuous production of lithium metal from lithium carbonate or other lithium salts by use of an aqueous acid electrolyte and a lithium producing cell structure which includes: a cell body with a cathode within the cell body; an electrolyte aqueous solution within the cell body, the solution containing lithium ion and an anion; and a composite layer intercalated between the cathode and the electrolyte aqueous solution, the composite layer comprising a lithium ion conductive glass ceramic (LI-GC) and a lithium ion conductive barrier film (LI-BF) that isolates cathode-forming lithium from the electrolyte aqueous solution.

What is claimed is: 
     
         1 : A process for continuously producing lithium on a cathode comprising:
 providing an electrolytic cell comprising:
 a lithium feed solution comprising a sulfuric acid solvent and a lithium ion source selected from the group consisting of lithium carbonate, lithium chloride, spodumene, and combinations thereof; 
 an anode in contact with the lithium feed solution; 
 the cathode; and 
 a composite layer between the cathode and the lithium feed solution, the composite layer comprising a lithium ion conductive glass ceramic material and a lithium ion conducting electrolyte between the lithium ion conductive glass ceramic material and the cathode; and 
   providing an ionizing electric current to the electrolytic cell to continuously produce lithium metal at the cathode,   wherein the composite layer isolates the lithium metal produced at the cathode from the lithium feed solution as the lithium metal is formed, and the lithium feed solution is continuously provided.   
     
     
         2 : The process for producing lithium of  claim 1 , wherein the lithium ion conducting electrolyte is an ionic liquid. 
     
     
         3 : The process for producing lithium of  claim 1 , wherein the lithium ion conducting electrolyte is a non-aqueous electrolyte. 
     
     
         4 : The process for producing lithium of  claim 1 , wherein the composite layer has an ion conductivity of at least 10 −7  S/cm and is nonreactive to both lithium metal and the cathode. 
     
     
         5 : The process for producing lithium of  claim 1 , wherein the cathode is moveable along an axis of the electrolytic cell away from the anode as the lithium metal is produced at the cathode. 
     
     
         6 : The process for producing lithium of  claim 1 , wherein a physical distance is present between the cathode and the lithium ion conductive glass ceramic material. 
     
     
         7 : The process for producing lithium of  claim 1 , wherein:
 the electrolytic cell comprises a first portion containing the cathode and a second portion containing the lithium feed solution, and   the electrolytic cell is configured to drive the cathode away from the lithium ion conductive glass ceramic as the lithium metal is formed on the cathode.   
     
     
         8 : The process for producing lithium of  claim 1 , wherein:
 the lithium ion source consists of a lithium salt that dissociates in the sulfuric acid solvent, and   a non-lithium portion of the salt is released from the solution as a gas.   
     
     
         9 : The process for producing lithium of  claim 1 , wherein the lithium metal produced at the cathode is drawn off as a pure metallic phase. 
     
     
         10 : The process for producing lithium of  claim 1  comprising drawing off the lithium metal produced at the cathode, without any additional extraction processes. 
     
     
         11 : A process for continuously producing lithium on a cathode comprising:
 providing a lithium feed solution comprising a hydrated acid solvent and a lithium ion source selected from the group consisting of lithium carbonate, lithium chloride, spodumene, and combinations thereof dissolved in the hydrated acid solvent;   providing a composite layer between a cathode and the lithium feed solution, the composite layer comprising a lithium ion conductive glass ceramic material and a lithium ion conducting electrolyte between the lithium ion conductive glass ceramic material and the cathode; and   generating a current across the lithium feed solution to continuously produce lithium metal at the cathode,   wherein the composite layer isolates the lithium metal produced at the cathode from the lithium feed solution as the lithium metal is formed, and the lithium feed solution is continuously provided.   
     
     
         12 : The process for producing lithium of  claim 11 , wherein the hydrated acid is sulfuric acid. 
     
     
         13 : The process for producing lithium of  claim 11 , wherein the lithium feed solution is selected from the group consisting of: a sulfuric acid electrolyte and a sulfuric acid leaching solution. 
     
     
         14 : The process for producing lithium of  claim 11 , wherein the lithium ion conducting electrolyte is an ionic liquid. 
     
     
         15 : The process for producing lithium of  claim 11 , wherein the lithium ion conducting electrolyte is a non-aqueous electrolyte. 
     
     
         16 : The process for producing lithium of  claim 11 , wherein a physical distance is present between the cathode and the lithium ion conductive glass ceramic material. 
     
     
         17 : The process for producing lithium of  claim 11 , wherein the lithium metal produced at the cathode is drawn off as a pure metallic phase. 
     
     
         18 : The process for producing lithium of  claim 11 , comprising drawing off the lithium metal produced at the cathode, without any additional extraction processes. 
     
     
         19 : A continuous lithium-producing cell for producing lithium on a cathode, comprising:
 a continuously-provided lithium feed solution comprising a sulfuric acid solvent and a lithium ion source selected from the group consisting of lithium carbonate, lithium chloride, spodumene, and combinations thereof;   an anode in contact with the lithium feed solution;   a cathode; and   a composite layer between the cathode and the lithium feed solution, the composite layer comprising a lithium ion conductive glass ceramic material and a lithium ion conducting electrolyte between the lithium ion conductive glass ceramic material and the cathode;   wherein the composite layer isolates the lithium metal produced at the cathode from the lithium feed solution as the lithium metal is formed.   
     
     
         20 : A lithium metal product comprising lithium metal produced by the process of  claim 1 .