Challenges and strategies for aluminum-air batteries

Kurzfassung

Aluminum-air (Al-air) batteries are considered promising candidates for electrochemical energy storage due to their theoretical energy density (~8,100 Wh kg-1), specific capacity (~3000 mAh·g-1), low cost and the natural abundance of aluminum. However, several hurdles must be overcome before their widespread application. Notably, the aluminum anode is prone to passivation and corrosion, which reduces the effective utilization of the metal. In addition, the sluggish oxygen reduction reaction (ORR) affects the air cathode and significantly decreases the electrochemical performance of the system. These problems are mitigated with different strategies: the aluminum anode is usually coated with other metal elements to improve the battery performance. On the other hand, different materials have emerged to improve the oxygen reduction reaction activity in the air cathode, such as metal-organic frameworks (MOFs). In this mini-review, the challenges and recent advances in aluminum-air technology are examined, highlighting the use of metal-organic frameworks as catalysts for the air cathode and the application of different coating strategies to improve the stability and performance of the aluminum anode.