Surface Finishing Technology for Li-Al Alloy Anode of Lithium Rechargeable Battery

Dendritic precipitation of lithium during charging is a problem in practical application of a lithium secondary battery. Although it is known that Li-Al alloy precipitated on aluminum is effective as the countermeasure to the problem, smooth precipitation is required for high efficiency in charging-discharging cycle. A paper reports on investigation on the effect of surface treatment for obtaining smooth precipitation. Different surface state such as rolled, polished, electropolishing, etc. and additional floric acid etching were tested. It was found that fluoric acid etching of an Al cathode is effective for prolonging life of an Al-Li alloy cathode. Currently prototype test is proceeding.