Defective carbon-bridged Cu sites to boost oxygen reduction reaction in neutral zinc-air batteries

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Novel carbon nanomaterials containing N-coordinated metal centers present an advantage in promoting the oxygen reduction reaction (ORR). Despite considerable progress, substantial challenges persist with the advancement of neutral Zinc-air batteries (ZABs), particularly in optimizing the trade-off between the catalytic activity and stability. Herein, employing nanoporous carbon impregnated with Cu(II)-phenanthroline complexes to prepare Cu-ONCs catalysts rich in Cu-Nx sites. Controllable carbon defects to capture Cu2+ enable the enrichment of metal sites on the porous carbon surface, and simultaneously effectively suppress the aggregation of active centers. The metal moieties, specifically Cu-Nx, are incorporated into the porous N-doped carbon, thereby introducing accessible active sites within the partially graphitized carbon framework. Furthermore, the abundant mesopores inside the carbon nanofibers promote the exposure of accessible active sites to substantially augment the electrochemically active electrochemically active area area. Given the unique structure and composition, Cu-ONCs show outstanding ORR activity in neutral and alkaline media, alone with negligible decay observed after 3000 cycles. Moreover, Cu-ONCs based neutral ZABs demonstrate a peak power density of 48.28 mW cm−2 and impressive rate performance. This work provides defects/vacancies insight on transition metal (TM)-based carbon support to facilitate the advancement of cutting-edge neutral ZABs.