3D-porous and smooth surface anodes for the Al-air battery: Al electrodes were produced with smooth and porous surfaces by salt casting. LSV analysis showed that the current density of the porous electrode was three times higher. EIS analysis gives lower charge transfer resistance for the Al-porous electrode. The power density of the Al-porous electrode was approximately 42 % higher than that of the Al-smooth electrode.
Abstract
This study compared the electrochemical performances of porous surface electrodes obtained by the salt casting process against a smooth surface electrode. Potentiodynamic polarization test, linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) tests of porous and smooth Al electrodes were performed using 0.5 M NaOH solution. According to the Tafel analysis, the Jcor value of the Al-porous electrode was measured as 3.23 mA cm−2, which is approximately 55 % higher than the Al-smooth electrode. The Ecor value was more negative for the Al-porous electrode. Results of the low charge transfer resistance (2.2 Ω) of the Al-porous electrode compared to the Al-smooth electrode (2.8 Ω) concluded that the porous surface was increased the current density by increasing charge transport due to higher surface area. The galvanostatic discharge tests of the electrodes were carried out in an Al-air battery test cell using a graphite carbon air cathode. As a result, the power density of the Al-porous electrode was approximately 42 % higher than the Al-smooth surface electrode.
