Investigations On The Negative Electrode Materials Of Aluminum-air Batteries

Since entering the 21st century,science and technology have ushered in rapid development.With the advancement of science and technology,people's demand for energy storage equipment is increasing.The development of energy storage equipment has a decisive role in electronic equipment and electric vehicles.In this paper,according to the problems existing in aluminum-air batteries,the energy of the system formed by alloying elements and pure aluminum is calculated based on the first-principles software MS.By comparing the relative energy,the elements that can improve the electrochemical activity of aluminum metal are screened out.On the basis of calculation,the three elements of ReA,ReB and Sn were selected to be alloyed with pure aluminum,and the electrochemical properties of the alloy were characterized by polarization curve,Electrochemical Impedance Spectroscopy,and galvanostatic discharging.The corrosion performance of the alloy was tested by self-corrosion test.SEM was used to observe the surface morphology of the alloy after galvanostatic discharge test.XRD was used to investigate the internal microstructure of alloyed aluminum.Finally,based on the experimental results of three binary alloys,a quaternary Al-ReA-ReB-Sn alloy was prepared and its properties were comprehensively analyzed.According to the original calculation of the energy of the alloy system,the single point energy of the rare earth elements alloyed with pure aluminum is the most negative and far higher than that of pure aluminum.Through the electrochemical tests of Al-ReA alloy and Al-ReB alloy,the addition of alloying element ReA can increase the current density at the same potential.The electrochemical activity of Al-0.8 wt%ReA alloy is90%higher than that of pure aluminum.The addition of alloying element ReB can increase the electrochemical activity and utilization of the anode of the aluminum-air battery,and the effect is related to the content of alloying elements.The Al-ReB alloy phase has a more negative open circuit potential than pure aluminum.The analysis of the anodic polarization process of Al-Sn alloy shows that the Al-Sn alloy has a"super-activation"process during the polarization process.The galvanostatic discharge analysis shows that when the current density is appropriate,the intensive current fluctuation of the galvanostatic discharge curve of Al-Sn alloy with higher concentration of Sn will occur,and the fluctuation amplitude will exceed 100mV.Based on the experimental phenomena of Al-Sn,a mechanism that can effectively explain the potential fluctuation during constant current discharge is proposed.In the polarization curve,when the Sn content was 0.12%,the current density of the Al-ReA-ReB-Sn alloy at-1.2 V reached a maximum value of-100.96 mA·cm^-2,which was 51%higher than that of pure aluminum.The open circuit potential of the quaternary Al-ReA-ReB-Sn alloy is negatively shifted by 100 mV compared to pure aluminum.The galvanostatic discharge analysis shows that when the content of Sn in Al-ReA-ReB-Sn alloy is 0.12wt%,the alloy reaches the most negative potential during the discharge process,which is negatively shifted by 140 mV compared with pure aluminum.