Effect of Ce addition on the microstructure and properties of Al-Cu-Mn-Mg-Fe lithium battery shell alloy

Abstract Effect of Ce addition on the microstructures, mechanical properties and electrochemical properties of Al-Cu-Mn-Mg-Fe lithium battery alloy was investigated by optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), tensile testing and electrochemical testing. Experimental results indicate that Ce addition resulted in the formation of Al 8 Cu 4 Ce phase in the Al-Cu-Mn-Mg-Fe alloy. The Ce-containing precipitates nucleated and grew up along the surface of Al 6 (Mn, Fe) precipitates. Al 6 (Mn, Fe) precipitates could be remarkably refined by Ce alloying. The aging precipitation behavior of Sˈ phases could be promoted after Ce addition to the alloy. In comparison with Ce-free alloy, the Ce-containing alloy had higher tensile strength at both low temperature and elevated temperature. Especially at 200 °C, the yield strength and tensile strength of Ce-containing alloy substantially increased by 23.4% and 27.08%, respectively. Potentiodynamic polarization testing indicated that the Ce-containing alloy had a more positive corrosion potential and a lower corrosion current density.