Hybrid high-concentration electrolyte significantly strengthens the practicability of alkaline aluminum-air battery

Abstract Alkaline aluminum-air batteries show great potential for energy storage applications because of their high theoretical energy density and low cost. However, they are suffering from severe anodic self-corrosion and the gelation of electrolyte which greatly reduce the practical energy density and shelf life. Herein, we firstly construct an efficient high-energy alkaline Al-air battery based on high-concentration potassium acetate-potassium hydroxide electrolyte and prototype optimization. The self-corrosion of Al anode is greatly suppressed owing to the special hydrate structure in such electrolyte. The Al-air battery with optimum electrolyte demonstrates remarkable increased discharge capacity of 2324 mAh g−1, and the constructed miniaturized Al-air battery enables an outstanding system energy density of 436.1 Wh kg−1 (compared with 85.8 Wh kg−1 of normal electrolyte) after integrating a discharge product removing system. This work opens up a new direction for the practical realization of high-energy, low-cost, and high-efficiency alkaline Al-air battery and other aqueous metal-air batteries.