Aerobically Autoxidized Self-Charge Concept Derived from Synergistic Pyrrolic Nitrogen and Catechol Configurations in N, O Co-Doped Carbon Cathode Material

Aerobically autoxidized self-charging concept has drawn significant attraction due to its promising chemical charge features without external power supply. Particularly, heteroatom-doped carbon materials with abundant oxidizable sites and good conductivity are expected to be ideal cathode materials. However, there is no well-defined aerobically autoxidized self-charging concept based on heteroatom-doped carbon materials, significantly hindering the design of related carbon cathodes. An aerobically autoxidized self-chargeable concept derived from synergistic effect of pyrrolic nitrogen and catechol configuration in carbon cathode using model single pyrrolic nitrogen and oxygen (N-5, O) co-doped carbon and O-enriched carbon is proposed. First, self-charging of N-5, O co-doped carbon cathode can be achieved by aerobic oxidation of pyrrolic nitrogen and catechol to oxidized pyrrolic nitrogen and ortho-quinone configurations, respectively. Second, introducing a single pyrrolic nitrogen configuration enhanced acidic wettability of N-5, O co-doped carbon facilitating air self-charge/galvanic discharge involving proton removal/introduction. Third, synergistic effect of pyrrolic nitrogen and hydroxyl species with the strong electron-donating ability to conjugated carbon-based backbone endows N-5, O co-doped carbon with a higher highest occupied molecular orbital (HOMO) energy level more susceptible to oxidation charging. The assembled Cu/Carbon batteries can drive a timer after every air-charging run. This promising aerobically autoxidized self-charging concept can inspire exploring high-efficiency self-charging devices.