Abstract: The effects of addition of rare earth metals on the electrochemical performance of Li-Al alloy as a negative electrode in secondary lithium battery were studied using cyclicvoltammetry, charge- discharge operation and electrochemical impedance measurement.Li-Al and Li-Al-RE alloys were prepared respectively by underpotential deposition ofLi on pure Al and Al-RE alloys in argon atmosphere and 1M LiClO₄/propylene carbonateelectrolyte at 25℃.The results showed that with addition of ca. 1.0% rare earth elementsthe anodic peak current in the voltammogram of Li-Al alloys increased in a few mA/cm² for 99% Al matrix and in more than 10 mA/cm² for 99.9% Al matrix, and the charge-dis-charge efficiencies increased in 10% and 20%, respectively.The reaction resistance of Li-Al-RE alloy was smaller than that of Li-Al alloy.This beneficial effect is likely due tothe nucleation action of the rare-earths as a foreign element in alloy, which changes thestructure of Li-Al alloys and make the insertion and diffusion of Li into Al easier.

Key words: Secondary battery, Rare earth-aluminium alloy, Lithium electrode, Rare earth element