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 lithium producing cell structure, comprising:
 a cell body with a cathode within the cell body;   a sulfuric acid 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.   
     
     
         2 . The lithium producing cell of  claim 1 , wherein the composite layer is characterized by high lithium metal ion conductivity and is nonreactive to both lithium metal and the LI-GC material. 
     
     
         3 . The lithium producing cell of  claim 1 , wherein the lithium ion conductive barrier film of the composite layer comprises a physical organogel electrolyte. 
     
     
         4 . The lithium producing cell of  claim 1 , wherein the lithium ion conductive barrier film of the composite layer comprises an organogel product of an in situ thermo-irreversible gelation and single ion-predominant conduction. 
     
     
         5 . The lithium producing cell of  claim 1 , wherein the composite layer comprises a lithium ion conductive glass ceramic and a lithium ion conductive barrier film. 
     
     
         6 . The lithium producing cell of  claim 1 , wherein the substantially impervious ionically conductive polymeric separator layer comprises a glass-ceramic active metal ion conductor. 
     
     
         7 . The lithium producing cell of  claim 1 , wherein the lithium ion conductive glass ceramic (LI-GC) is an ion conductive glass-ceramic having the following composition in mol percent: P 2 O 5  26-55%; SiO 2  0-15%; GeO 2 +TiO 2  25-50%; in which GeO 2  0-50%; TiO 2  0-50%; ZrO 2  0-10%; M 2 O 3  0-10%; Al 2 O 3  0-15%; Ga 2 O3 0-15%; Li 2 O 3-25% and containing a predominant crystalline phase comprising Li 1+x (M, Al, Ga) x (Ge 1-y Ti y ) 2-x (PO 4 ) 3  where X≦0.8 and 0≦Y≦1 and where M is an element selected from the group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb, and/or Li 1+x+y Q x Ti 2-x Si 3 P3-yO 12  where 0<X≦0.4 and 0<Y≦0.6, and where Q is AI or Ga. 
     
     
         8 . The lithium producing cell of  claim 1 , wherein the composite layer has an ionic conductivity of at least 10 −4  S/cm. 
     
     
         9 . The lithium producing cell of  claim 1 , wherein the cathode comprises a catholyte selected from the group consisting of non-aqueous electrolyte 
     
     
         10 . The lithium producing cell of  claim 1 , wherein the cathode further comprises electrochemically active material selected from the group consisting of solid, liquid and gaseous oxidizers. 
     
     
         11 . The lithium producing cell of  claim 1 , wherein the catholyte comprises an ionic liquid. 
     
     
         12 . The lithium producing cell of  claim 1 , wherein the composite layer comprises a substantially impervious protective ceramic composite layer and the lithium ion conductive barrier film. 
     
     
         13 . The lithium producing cell of  claim 1 , wherein cathode is movable along an axis of the cell. 
     
     
         14 . A process for producing lithium, comprising:
 providing a lithium ion source in a sulfuric acid solvent wherein lithium anion is dissolved in the solvent to form a lithium feed solution;   providing an anode in contact with the solution;   providing a cathode suitable for electrolysis of lithium, wherein the cathode in contact with the solution through a composite ion-conducting barrier forms an electrolysis cell;   providing an ionizing electric current to the electrolysis cell thereby producing lithium metal at the cathode; and   providing a composite layer transecting an axis of the cell body, the composite layer, comprising a lithium ion glass ceramic and lithium, ion conductive barrier film that isolates cathode-forming lithium from the anion-containing solution as lithium metal is formed.   
     
     
         15 . The process for producing lithium of  claim 14 , wherein the composite layer is characterized by high lithium metal ion conductivity and is nonreactive to both lithium metal and the LI-GC material 
     
     
         16 . The process for producing lithium of  claim 14 , wherein the cathode is drivable along a cell axis away from anode as lithium metal is deposited on the cathode. 
     
     
         17 . The process for producing lithium of  claim 14 , wherein, the cell is postured with upper moving cathode and lower cell containing electrolyte to drive the cathode away from the composite ion conducting layer as lithium metal is deposited on the cathode. 
     
     
         18 . The lithium producing cell of  claim 14 , wherein the lithium ion conductive barrier film of the composite layer comprises a physical organogel electrolyte. 
     
     
         19 . The lithium producing cell of  claim 14 , wherein the lithium ion conductive barrier film of the composite layer comprises an organogel product of an in situ thermo-irreversible gelation and single ion-predominant conduction. 
     
     
         20 . The process of  claim 14  where the lithium ion source is lithium carbonate 
     
     
         21 . The process of  claim 14  where the lithium ion source is another lithium salt which dissociates in an acid solvent placing the lithium ions into solution and releasing the non-lithium portion of the salt as a gas. 
     
     
         22 . The process of  claim 14  where the acid is other than sulfuric acid but dissociates the lithium source in the same manner, placing lithium ions into solution while releasing the non-lithium portion of the source as a gas.