Progress and Complexities in Metal-Air Battery Technology

Metal-air batteries (MABs) offer exceptional energy density, making them attractive for vehicle electrification and storing intermittent renewable energy. However, several challenges persist, including sluggish oxygen reduction and oxygen evolution reactions, interfacial stability issues, and challenges related to current collectors. Herein, the reasons behind MAB's failures are analyzed, considering their thermodynamic aspects (Gibbs free energy, entropy), electrochemical factors (redox potentials, polarization, and ion concentrations), and kinetic properties (mobility of charges). Strategies for mitigating energy barriers of the electrodes are explored, encompassing insights into the initiation process of the oxygen reduction and determinants of oxygen evolution kinetics. The impact of humidity on the electrolyte is assessed, and effective methods for dendrite prevention are elucidated. Additionally, the utilization of 3D electrodes, oxygen-selective membranes, solid-state electrolytes, hybrid polymer electrodes, conductive electrocatalysts, and artificial solid-electrolyte interfaces, and their effects on addressing the challenges faced by MABs are discussed. The study also emphasizes six critical commercialization aspects for the advancement of MABs. Lastly, the potential prospects and challenges in the field of MAB technology are discussed. Challenges and solutions for metal-air batteries (MABs), emphasize the interplay of electrode potentials, thermodynamics, kinetics, and electrochemical traits in MABs. Key factors include electrolyte composition, electrode morphology, and metal oxide/hydroxide solubility at the cathode.image (c) 2024 WILEY-VCH GmbH