Anode Interfacial Layer Construction via Hybrid Inhibitors for High-Performance Al-Air Batteries

The self-corrosion of aluminum anodes is one of the key issues that hinder the development and application of low-cost and high-energy-density Al-air batteries (AABs). Herein, a hybrid corrosion inhibitor combining ZnO and acrylamide (AM) was developed to construct a dense protective interface on the Al anode to suppress the self-corrosion and enhance the electrochemical performance of AABs. Also, the results show that the hydrogen evolution rate with the optimal combination of hybrid inhibitors is 0.0848 mL cm^-2 min^-1, corresponding to the inhibition efficiency of 78.03%. The integrated AABs with hybrid inhibitors show remarkable capacities of 1240.6 mA h g^-1 (25 mA cm^-2) and 2444.1 mA h g^-1 (100 mA cm^-2) and a high power density of 63.7 mW cm^-2. This shows that ZnO dissolves into the electrolyte and forms a loose and porous film on the Al surface. When AM is introduced into the ZnO-containing electrolyte, the adsorption of the amide group of AM on the surface of aluminum and ZnO occurs, which not only controls the growth morphology of ZnO but also enables ZnO to easily aggregate into a layer that is in close contact with the anode, efficiently suppressing self-corrosion. This work opens up the prospect of a corrosion inhibition mechanism for ZnO and AM in alkaline solutions and for developing effective organic/inorganic hybrid inhibitors.