Electrode behavior has been studied for producing Al-Li alloys in molten salts containing LiCl. A cathode is molten aluminum, and lithium deposits electrolytically into it. An anode is graphite and acts as a chlorine evolution electrode. The electrolysis has been carried out at 973 K by using LiCl single melt, LiCl-NaCl and LiCl-KCl eutectic mixture melts in order to study the electrochemical behavior of the cathode related to the current efficiency and the impurities such as sodium and potassium. For the case of LiCl single melt, required composition of Al-Li alloy up to 10 mass%Li was easily obtained with high current efficiency, 93-99%, and low level impurities less than 20 ppm which is comparable to the level in the commercially pure aluminum. For the case of LiCl-NaCl melt, the current efficiency somewhat decreased and about 320 ppm of sodium was contained in the alloy. For the case of LiCl-KCl melt, the current efficiency markedly decreased although no potassium increase was observed. The reason for the decrease in the current efficiency is considered to be that the impurities deposit by concentration overvoltage and dissolve into the melt. However, these effects are negligible unless the melt contains large amounts of impurity salts.
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