Method for making lithium aluminide compound with high lithium content

Abstract

A method for making lithium aluminide compound with high lithium content is disclosed. The method includes applying an electrolyte composed of lithium chloride, potassium chloride, and calcium chloride to accomplish a diffusive electrolysis under 380˜550° C. temperature. The lithium atoms of the electrolyte are reduced and diffused into an aluminum cathode, and liquid lithium aluminide is formed and floats on the electrolyte. The liquid lithium aluminide is further scooped up from the upper electrolyte and solidified to a lithium aluminide compound with 40˜62 wt % lithium content.

1 . A method for making lithiumaluminide compound with high lithium content, and the method comprising:
 providing an electrolytic bath, where the electrolytic bath includes an anode and a cathode, and the cathode is formed by an aluminum material;   filling an electrolyte in the electrolytic bath, the electrolyte essentially consisting of lithium chloride, potassium chloride, and calcium chloride, and having a temperature kept within a range of 380° C.˜550° C.;   exerting an electric current with current density of 0.08 A˜0.1 A per unit area of cathode surface (cm 2 ) to the electrolyte to reduce and diffuse a plurality of lithium atoms of the lithium chloride into a cathode surface of the cathode, and form a liquid lithium aluminum floating on the electrolyte; and   removing the liquid lithium aluminum from the electrolyte and solidifying the liquid lithium aluminum to a lithium aluminide compound.   
   
   
       2 . The method of  claim 1 , wherein the electrolyte essentially consists of 20˜40 wt. % lithium chloride, 30˜50 wt. % potassium chloride, and less than 10 wt. % calcium chloride. 
   
   
       3 . The method of  claim 1 , wherein the temperature of the electrolyte is kept at 500° C. 
   
   
       4 . The method of  claim 1 , wherein the current density of the electric current is kept at 0.08 A per unit area of cathode surface (cm 2 ). 
   
   
       5 . The method of  claim 1 , wherein the anode is a graphite anode. 
   
   
       6 . The method of  claim 1 , wherein the composition of the lithiumaluminide compound is within the range of Al-40 wt. % Li˜Al-62 wt. % Li. 
   
   
       7 . The method of  claim 1 , further comprises using a mold to solidify the liquid lithium aluminum.