Metal-Air Batteries: From Fundamental Mechanisms to Practical Applications

Metal–air batteries (MABs) have attracted significant attention as next-generation energy storage systems due to their high theoretical energy densities, lightweight designs, and potential cost-effectiveness. This review presents a comprehensive analysis of MAB systems, focusing on lithium–air, sodium–air, magnesium–air, zinc–air, and aluminium–air batteries. Key contributions include a detailed discussion of nanomaterial advancements for cathode and anode development, the role of bifunctional catalysts for enhancing oxygen reduction and evolution reactions (ORR/OER), and the emerging integration of artificial intelligence (AI) for material optimization and predictive modeling. The major limitations of MABs, such as sluggish reaction kinetics, electrode passivation, electrolyte instability, and poor rechargeability, are critically analyzed, highlighting their impact on practical performance. Comparative evaluations of thermodynamics, electrochemical properties, and material strategies in this review help in the identification of pathways to overcome these bottlenecks. Practical implications for real-world applications are discussed, emphasizing the need for stable catalysts, protected anode designs, novel electrolyte systems, and sustainable recycling processes. The future outlook suggests that interdisciplinary innovation combining material science, electrochemistry, AI-driven modeling, and scalable engineering will be pivotal for advancing MAB technologies toward commercialization and contributing to a sustainable energy future.