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. • Al-5Zn-0.1Sn-0.1In-0.1Bi alloy is first synthesized which displays high discharging performance in battery applications. • XRD, SEM, and TEM showed the minor crystals and grains in Al-5Zn-0.1Sn-0.1In-0.1Bi. • The self-corrosion is examined indicating a dissolution mechanism of the Al alloy. • In and Bi in the Al alloy collapsed during discharge, which refreshed the passivated Al surface. [ABSTRACT FROM AUTHOR]