Current progresses and future prospects on aluminium–air batteries

Metal–air batteries have been considered as promising battery prototypes due to their high specific capacity, energy density and easily available nature of air. Al can be regarded as an attractive candidate because of its abundant reserve (the most abundant metal element in the earth's crust), low price (1.9 USD·kg^–1), high theoretical capacity density of 2.98 Ah·g⁻¹ and high energy density of 8.1 Wh·g⁻¹. For meeting the level of commercialization, nevertheless, there are still many scientific and technical challenges to overcome in the Al–air batteries. In this review, a comprehensive overview of Al–air batteries is initially provided, along with highlighting recent progresses in high-performance Al anodes, advanced air cathodes and improved electrolytes for Al–air batteries. The analysis and discussion on the progresses and challenges for Al–air batteries here are expected to provide a meaningful guide for future efforts to boost Al–air batteries.