Chamber for reaction of lithium and deuterium

Abstract

An electrochemical device is described which consists of two electrolyte chambers separated by a common electronically conducting cathode, such as a metal foil. On one side of the common cathode is a non-aqueous electrolyte which does not react with lithium metal and from which lithium metal may be plated. On the other side of the common cathode is an aqueous electrolyte from which isotopes of hydrogen may be electrochemically reduced on the common cathode. The cathode is impervious to either electrolyte. The anode on the non-aqueous side contains lithium metal, and on the aqueous side, the anode is an electronically conductive material which will not react with the electrolyte during the electrochemical release of oxygen. The purpose of the common cathode is to bring elemental lithium and elemental hydrogen together by diffusion within a metallic matrix, free of either electrolyte. Additionally, a non-electrochemical device is described which allows isotopes of lithium and hydrogen to interact within an alloy capable of absorbing both elements in a condensed phase.

1 . An apparatus for introducing deuterium and lithium into a metallic matrix comprising: 
 a double-chambered electrochemical cell in which each chamber contains a different liquid electrolyte, one aqueous (solvent plus conductive solute) and the other non-aqueous (solvent plus conductive solute), the non-aqueous electrolyte being heat resistant and one from which lithium can be plated;    an electronically conductive membrane arranged so as to separate the chambers, the membrane impervious to each of the liquid electrolytes but capable of absorbing both elemental lithium and elemental hydrogen (deuterium), and serving as the cathode for both chambers;    a lithium anode situated in the non-aqueous electrolyte serving as the counter electrode for that chamber, a current thereby causing lithium to be electrochemically plated on the membrane from the non-aqueous side, and allowing the metal to begin diffusing into the membrane; and    a second anode on the aqueous side to serve as a counter electrode for applying a cathodic current to the membrane, thereby electrochemically reducing hydrogen (deuterium) from the aqueous side, and also causing hydrogen to diffuse into the membrane, and thus causing the deuterium and lithium elements to meet within the membrane, each free of their respective electrolyte.    
   
   
       2 . An apparatus as in  claim 1  wherein the electrically conductive membrane is palladium foil, or a foil prepared from an alloy of palladium with silver.  
   
   
       3 . An apparatus as in  claim 1  wherein the solvent in the aqueous side is light water (H 2 O), heavy water (D 2 O), or a mixture.  
   
   
       4 . An apparatus as in  claim 1  wherein the lithium anode comprises metallic lithium, either essentially of isotope mass  6 , or mass  7 , or a mixture thereof, pressed onto a nickel screen.  
   
   
       5 . An apparatus as in  claim 1  wherein the second anode is formed from one of nickel or platinum.  
   
   
       6 . An apparatus as in  claim 1  wherein the conductive solute in the aqueous electrolyte is selected from sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, trichloroacetic acid, toluenesulfonic acid or mixtures thereof, and lithium, sodium, potassium, rubidium, cesium hydroxide (deuteroxide) or mixtures thereof.  
   
   
       7 . An apparatus as in  claim 1  wherein the conductive solute in the aqueous electrolyte is selected from alkali, alkaline earth sulfates, carbonates such as Is lithium, sodium, potassium, or magnesium sulfate, sodium, or potassium carbonate.  
   
   
       8 . An apparatus as in  claim 1  wherein the conductive solute in the aqueous electrolyte is selected from hyrdohalic acids such as hydrochloric acid, halide salts such as alkali chlorides, bromides, or iodides, or acids or salts of toxic or reactive species thereof such as nitrates, chlorates, perchlorates, iodates, periodates, bromates, or oxalates.  
   
   
       9 . An apparatus as in  claim 1  wherein the non-aqueous electrolyte is thermally stable at temperatures from ambient up to at least 100 degrees centigrade (the boiling point of water), preferably have relatively low vapor pressure over this range, and most important, not react with lithium at an appreciable rate at least up to and preferably beyond this temperature.  
   
   
       10 . An apparatus as in  claim 1  wherein the non-aqueous solvent is selected from a glycol ether such as diethylene glycol dimethyl or diethyl ether, triethylene glycol dimethyl or diethyl ether, or tetraethylene glycol dimethyl or diethyl ether, the methyl and ethyl ethers of 1,3-propane diol and propylene glycol, or mixtures thereof, and the conductive solute includes a salt of lithium 6, lithium 7, or a mixture, the anion being selected from bis-(oxalato)borate, malonato-oxalatoborate, bis-(malonato)borate, tris-(oxalato)phosphate, tetrafluoroborate, hexafluorophosphate, bis-(trifluoromethanesulfonyl) imide, trifluoroacetate, perfluoroethanetrifluoromethanesulfonylimide, bis-(perfluoroethanesulfonyl) imide, trifluoromethane sulfonate, tetrachloroaluminate, trifluoromethanetrifluoroacetylsulfonyl amide, and closo-carborates and closo-borates such as B 11 X 11 CX − , B 12 X 12   2− , or B 10 X 10   2− ,where X is hydrogen, a halogen such as F, Cl, Br, or I, or a mixture.  
   
   
       11 . An apparatus as in  claim 1  wherein the non-aqueous solvent is a cyclic  15  carbonate ester such as ethylene or propylene carbonate, dimethyl sulfoxide, ethylene and propylene sulfite, sulfolane, succinic anhydride, or mixtures thereof.  
   
   
       12 . An apparatus as in  claim 1  additionally comprising: 
 a catalyst arranged to recombine the hydrogen (deuterium) and oxygen released by the electrolysis.    
   
   
       13 . An apparatus as in  claim 11  additionally comprising a vent for venting hydrogen (deuterium).  
   
   
       14 . An apparatus as in  claim 1  additionally comprising: a seal for the cell to enable operation under temperature and pressure above ambient.  
   
   
       15 . A hollow chamber of corrosion-resistant material containing a metallic alloy therein, the alloy capable of absorbing both lithium and hydrogen (deuterium) in a single phase.  
   
   
       16 . A chamber as in  claim 14  having cylindrical tube shape.  
   
   
       17 . A chamber as in  claim 15  which can be disassembled to charge the alloy.  
   
   
       18 . A chamber as in  claim 14  additionally comprising: 
 a gas-tight cover, which is additionally fitted with a leak-tight valve capable of allowing gasses in the chamber to be evacuated and through which hydrogen (deuterium) may then also be admitted.    
   
   
       19 . A chamber as in  claim 14  in which the metallic alloy is prepared from lithium and magnesium with 1 to 55% nickel by weight; calcium, lithium, and nickel; or magnesium, lithium, titanium, and nickel.  
   
   
       20 . A chamber as in  claim 14  in which the metallic alloy is prepared from nanoparticles.  
   
   
       21 . A chamber as in  claim 16  where the metallic alloy includes lithium  6 , lithium  7 , or a mixture of the two isotopes.