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

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 Al8Cu4Ce phase in the Al-Cu-Mn-Mg-Fe alloy. The Ce-containing precipitates nucleated and grew up along the surface of Al6(Mn, Fe) precipitates. Al6(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.