Engineering Advanced Electrocatalysts for Energy‐Saving Zinc−Air Hybrid Batteries: Concurrent Energy Storage Coupled With Chemical Upgrading

Abstract

Additive‐assisted zinc−air hybrid batteries (ZAHBs) that couple favorable additive oxidation with oxygen reduction represent ideal energy storage candidates, distinguished by high theoretical energy density, reduced charging voltage, and functionality for electrochemical upgrading of organics or wastewater. Herein, a critical overview of ZAHBs is provided, commencing with the fundamental electrochemistry (including advantages, working mechanisms, cell configurations, and evaluation parameters) and the selection criteria for small‐molecule additives (including theoretical potential, solubility, stability, toxicity, and volatility). We then summarize recent progress in three categories of ZAHBs (i.e., wastewater‐purified, value‐added, and redox‐mediated), discussing alternative anodic oxidation reactions (e.g., alcohol, urea, hydrazine, and iodine oxidation) coupled with cathodic oxygen reduction, along with the underlying catalytic mechanisms. Particular emphasis is placed on catalyst design strategies spanning electronic (ligand engineering, heteroatom doping, electron delocalization, orbital hybridization, and built‐in electric field), geometric (defect engineering, curvature engineering, and nano‐confinement effect), and interfacial (high‐energy interface, heterostructure, interfacial microenvironment, and core–shell structure) modulations. Finally, we discuss the remaining challenges and future perspectives for advancing ZAHBs. This review offers valuable guidance for the rational design and practical deployment of next‐generation energy devices.