Modifying cell parameters to improve aqueous aluminum battery performance with water-in-salt electrolytes

Aqueous aluminum batteries (AABs) have emerged as promising next generation batteries owing to their sustainability and high theoretical capacity. However, conventional aqueous electrolytes bring challenges, such as low voltage windows, and corrosion. Therefore, the new subclass of aqueous electrolytes, water-in-salt (WIS) electrolytes, are lately being considered. This study explores in detail aluminum/graphite (Al/G) cells utilizing WIS electrolytes. Parameters such as interelectrode distance, voltage range, and current density were investigated. The results revealed that cells with a 6 mm interelectrode distance, operating in the voltage range of 0.1–1.6 V at a current density of 0.5 Ag −1 , demonstrate the highest capacity (80 mAhg −1 ) in the stabilized cycle stage, compared with other configurations. • Al/graphite cell operation in a water-in-salt electrolyte was investigated and optimized. • The interelectrode distance significantly influenced the performance of the Al/graphite cell. • The cell within the voltage range of 0.1–1.6 V and a current density of 0.5 Ag −1 revealed the best cycling stability.