Aqueous Zn–CO₂ battery possesses a large theoretical capacity of 820 mAh g^-1 (5855 mAh cm^-3) and high safety, showing a unique position in carbon neutrality and/or reduction and energy conversion and storage, which has developed rapidly in recent years. However, obstacles such as low value-added products, low current density, high overvoltage, and finite cycles impede its practical application. Cathode catalysts, as a key component, have a significant influence on gas cell performance. Despite many updated papers on cathode materials for aqueous Zn–CO₂ batteries, a systematic summary has rarely been reported, and even less is mentioned about the design principle and development strategy for efficient catalysts. Relying on the structure and mechanism of the Zn–CO₂ battery, this review discusses the research progress and existing challenges, and, more importantly, the design strategies and preparation methods of the efficient cathode are proposed, centering on material structure, charge distribution, and coordination environment. Finally, in this review, the opportunities for the development of a high-performance Zn–CO₂ battery are highlighted, which enables enlightening the future exploration of next-generation energy storage systems.

Supercapacitors became more and more important recently in the area of energy storage and conversion. Their large power deliveries abilities, high stability and environmental friendliness characteristics draw tremendous attention in high-power applications such as public transit networks. Carbonaceous materials with unique surface and electrochemical properties were widely used in supercapacitors as electrode materials. This review focuses on the developments in supercapacitor electrodes made from carbonaceous materials recently, their working principle and evaluation parameters were summarized briefly. The preparation methods and electrochemical properties of different carbonaceous materials were compared and classified. It was found that the surface situation (e.g., porous structure, hydrophilic) of carbonaceous materials strongly affect the electrochemical performances of supercapacitor. So far, active carbons would be the most applicable carbonaceous electrode materials owing to their good chemical stability and conductivity, extensive accessibility inexpensiveness. But their energy densities still fall behind practical demands. Both theoretical calculations and experimental studies show that surface modification and doping of carbonaceous materials can not only optimize their pore size, structure, conductivity and surface properties, but also can introduce extra pseudocapacitance into these materials. Considering global environmental pollution and energy shortage problems nowadays, we sincerely suggested that future work should focus on domestic, medical and industrial wastes residues derived carbonaceous materials and scaled production process such as reactors and exhaust gas treatment.