Effect of cerium acetate and L-glutamic acid as hybrid electrolyte additives on the performance of Al–air battery

Abstract In this work, the effect of hybrid cerium acetate/L-glutamic acid (L-Glu) inhibitor on the self-corrosion inhibition and battery performance of Al-0.5Mg-0.1Sn-0.1Ga anode alloy is studied by experimental methods including hydrogen evolution tests, electrochemical measurements and surface analysis combined with theoretical methods including density functional theory calculation, crystal morphology simulation and Monte Carlo simulation. Results show that the hybrid inhibitor is cathodic inhibitor that effectively inhibits self-corrosion while slightly affecting the anode activity. An optimal efficiency of 77.85% is obtained by adding 10 mM of cerium acetate and 8 mM of L-Glu. At the current density of 20 mA cm−2 with optimal concentration, the discharge voltage and the capacity density increase from −1.737 V and 2,298.851 mAh g−1 to −1.835 V and 2,985.075 mAh g−1, respectively. Combining experimental with theoretical studies, indicate that the inhibition mechanism is that cerium acetate forms Ce(OH)3 in the alkaline electrolyte; and is then adsorbed on the alloy surface by the geometric covering effect, which promotes the adsorption of L-Glu. The Ce(OH)3/L-Glu and Al/L-Glu composite films effectively suppress the self-corrosion while slighting affecting the anode activity.