Effect of Si Addition on Mechanical and Electrochemical Properties of Al-Fe-Cu-La Alloy for Current Collector of Lithium Battery

The increasing demand for high-performance current collectors of lithium ion secondary batteries requires that the employed aluminum alloys have better mechanical properties and superior electrochemical performance. The effect of Si addition on the microstructure, tensile and electrochemical performance of Al-Fe-Cu-La alloy was investigated by optical microscopy, X-ray diffraction, scanning electron microscopy, a tensile test, conductivity test and Tafel polarization curve test. Experimental results indicated that Si addition to the Al-Fe-Cu-La alloy helped to refine the longitudinal grain size of the alloy. The Si-containing phase (AlFeSi) nucleated and grew along the surface of the AlFeLa phase. The Si addition to the Al-Fe-Cu-La alloy could greatly increase the tensile strength in the temperature range of &minus
20 &deg
C to 50 &deg
C and improve high temperature stability of the alloy. Also, the addition of Si promoted the formation of the AlFeSi ternary phase, which helped to improve the corrosion resistance of the alloy.