Benchmarking Anode Concepts: The Future of Electrically Rechargeable Zinc-Air Batteries

A variety of batteries employing an alkaline zinc anode have been investigated and partially commercialized over the last decades. Of these, electrically rechargeable zinc-air batteries have been considered, since the mid 20th century, as a sustainable alternative for future green energy storage. Despite significant research efforts, it has so far not been possible to commercialize this battery on a large scale because of insufficient performance. The herein presented overview is not yet another review; on the basis of a total of 70 articles published during the last 20 years in lab-scale research, we assess the state-of-the-art performance of alkaline zinc anodes for application in zinc-air batteries. We define descriptors for the underlying analysis focusing on the practical relevance and reveal that the expectations for this battery type are unfortunately too high. Most importantly, the ultimate long-lasting alkaline zinc anode has yet to be identified; this is a challenging, but appealing task for interdisciplinary research.