Advanced Technologies for High-Energy Aluminum-Air Batteries.

Aluminum-air batteries are considered as next-generation batteries owing to their high energy density with the abundant reserves, low cost, and lightweight of aluminum. However, there are several hurdles to be overcome, such as the sluggish rate of the oxygen reduction reaction (ORR) at the air electrode, precipitation of aluminum hydroxides and oxides at the anode, and severe hydrogen evolution problems at the interface of the anode and the electrolyte. Here, recent advances in silver metal and metal-nitrogen-carbon-based ORR electrocatalysts, aluminum anodes, electrolytes, and the requirements of future research directions are mainly summarized.