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 cyclic voltammetry, charge-discharge operation and electrochemical impedance measurement.Li-Al and Li-Al-RE alloys were prepared respectively by underpotential deposition of Li on pure Al and Al-RE alloys in argon atmosphere and 1M LiClO₄/propylene carbonate electrolyte at 25℃.The results showed that with addition of ca. 1.0% rare earth elements the anodic peak current in the voltammogram of Li-Al alloys increased in a few mA/cm² for 99% Al matrix and in more than 10mA/cm² for 99.9% Al matrix, and the charge-discharge 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 to the nucleation action of the rare-earths as a foreign element in alloy, which changes the structure of Li-Al alloys and make the insertion and diffusion of Li into Al easier.