Structural engineering of carbon-based cathodes for advanced aqueous Zn-CO₂ batteries: from macroscopic architectures to atomic-level manipulation

Aqueous Zn-CO₂ batteries, as safe and green energy storage devices that can simultaneously achieve the electrochemical CO₂ conversion for value-added chemical production and energy storage, have attracted wide attention. Carbon-based cathodes have been widely explored due to their tunable characteristics, but a comprehensive summary of multi-scale structural engineering is still lacking. This review first introduces the latest progress of Zn-CO₂ batteries, from battery mechanisms and systems to cathode structural design. The structural engineering of carbon cathodes at both the macroscopic level (e.g., morphology control, pore engineering, heterostructure, and interface engineering) and the atomic level (including heteroatom doping, defect engineering, and single-atom site engineering) is systematically summarized. This review emphasized the importance of synergistic design integrating atomic-level manipulation and macroscopic design for performance optimization, which is promising to provide guidance for the rational structural design of carbon-based cathodes for high-performance Zn-CO₂ batteries and other related energy storage devices.