Rechargeable Zn-air batteries: Recent trends and future perspectives

Currently a hot research topic, rechargeable zinc-air batteries are considered one of the most promising post lithium-ion battery technologies for utility-scale energy storage, electric vehicles, and other consumer electronics. Nevertheless, despite a high energy density, low cost, and material abundance, the development of alkaline-based Zn-air batteries has been hampered by parasitic reactions at the Zn anode and sluggish oxygen redox kinetics. This article will review the current status of Zn-air batteries, discuss recent development trends including neutral and hybrid Zn-air batteries, and highlight future research needs. Specifically, an analysis of the latest publications will show that, through redesigning the anode, introducing alternative electrolytes, and engineering high-performing bifunctional oxygen catalysts, researchers have successfully prolonged the battery reversibility to a few thousand cycles and reached unprecedented energy efficiencies over 70%. Although unsolved obstacles remain, these strategies have opened up interesting possibilities in the advancement of rechargeable Zn-air batteries, creating promising prospects for the energy and electronics industries. •Recent literature results of Zn-air batteries are critically assessed.•Current obstacles of alkaline-based and neutral Zn-air batteries are summarized.•Promising advancements in the anode, electrolyte, and oxygen catalyst are discussed.•Novel trends in solid-state and hybrid Zn batteries are highlighted.•Future perspectives are provided to guide systematic research contributions.