Effect of plastic deformation on discharge performance of aluminum–air battery

Abstract

In this study, the effect of plastic deformation on the discharge performance of an aluminum–air battery (AAB) was investigated. High-purity Al anodes were processed by cold rolling (CR) under different degrees of plastic deformation and analyzed using discharge tests. The discharge voltage and specific capacity initially increased and then decreased with extended cold rolling, achieving the highest values of 1.15 V and 2682.38 mAh/g_Al at 50 mA/cm² with 60 % deformation. Deformation via CR significantly affected the microstructure of the Al anode, where the preferred orientation of the crystal plane gradually changed from Al(111) to Al(200) when deformed up to 60 %, and remarkable grain refinement was only observed at 80 % deformation, inducing dynamic recrystallization with a change in the orientation toward Al(111). Although grain refinement can improve the discharge performance to a certain extent, preferred orientation along the Al(200) crystal plane played a dominant role in inhibiting the HER and improving the discharge performance of the AAB. Density functional theory calculation showed that Al(200) had a lower adsorption capacity for H₂O compared to Al(111), thereby improving the discharge performance of the AAB.