Dissolution of nanoprecipitate on aluminum-alloy anode for high discharging performance in Al battery applications

Use of aluminum alloy anodes as metal fuel in electrochemical batteries has specific advantages in numerous applications. In this paper, we report novel Al alloy anodes obtained by adding In and Bi to a reported Al ternary-element alloy, Al-Zn-Sn. An electron probe microanalyzer is used to obtain the elemental composition of Al-5Zn-0.1Sn, Al-5Z-0.1Sn-0.1In, and Al-5Zn-0.1Sn-0.1In-0.1Bi. Tafel analysis, electrochemical impedance spectroscopy, and constant-current chronopotentiometry are performed for electrochemical analysis. In addition, the self-corrosion of the alloys is examined to determine the hydrogen evolution and anode discharge stability. These results indicate that Al-5Zn-0.1Sn-0.1In-0.1Bi has the highest anode performance. On the basis of the scanning electron microscopy and transmission electron microscopy microstructure analysis, we propose that the dissolution and sedimentation process induced by Bi nanoprecipitates may activate a passive Al surface, significantly enhancing the discharge efficiency.