A Long‐Overlooked Pitfall in Rechargeable Zinc–Air Batteries: Proper Electrode Balancing

Abstract In times of an ever‐increasing demand for portable energy storage systems, post‐lithium‐based battery systems are increasingly coming into the focus of current research. In this realm, zinc–air batteries can be considered a very promising candidate to expand the existing portfolio of lithium‐based rechargeable battery systems due to their high theoretical energy density of 1086 Wh kg −1 . Despite a steady increase in research over the past 5 years, a breakthrough in realizing fully electrically rechargeable zinc–air batteries has yet to come. This perspective article highlights pitfalls that have probably hampered the development of rechargeable zinc–air batteries over years. This involves a fundamental evaluation of the zinc–air battery system, whereby fallacies of an alleged rechargeability are uncovered. Especially, the electrode balancing of the zinc anode as well as the interface between anode and electrolyte is focused herein. Known phenomena such as morphological changes are re‐evaluated by taking the contrasting battery stresses from shallow discharge to a highly desirable deep discharge into account. Existing challenges are discussed and prospected based on current approaches aiming to shed new light on a fundamental understanding and an opening of new avenues for rechargeability in zinc–air batteries.