Sustainable Zinc–Air Batteries: Innovations, Challenges, and Pathways to Commercialization

Sustainable zinc-air batteries (ZABs) are emerging as promising candidates for next-generation energy storage solutions, owing to their high theoretical energy density, intrinsic safety, and environmental sustainability. Despite their advantages, ZABs still require improvements in rechargeability and energy efficiency to be viable for practical applications and to replace less sustainable alternatives. These issues stem primarily from sluggish oxygen electrocatalysis, electrolyte instability, and degradation of zinc anodes. Addressing these challenges requires an integrated approach that targets key scientific and technological bottlenecks. While substantial progress has been made, achieving a synergistic optimization of critical performance factors remains elusive. These factors include the design of bifunctional oxygen electrocatalysts, engineering of the air cathode, optimization of the electrolyte, stabilization of the zinc anode, and development of innovative device architectures. This review systematically examines the crucial advancements required to advance ZAB technology. It highlights dynamic reconstruction of electrocatalysts to enhance both oxygen reduction and evolution reaction kinetics, innovations in electrolyte design to improve interfacial stability, strategies for achieving reversible zinc anode cycling, resilience across a wide temperature range, and the development of novel reactor designs, such as hybrid ZAB systems. Furthermore, this review evaluates the scalability of ZABs for industrial applications and addresses macro-level challenges, including cost-effectiveness and material availability.