Rechargeable zinc-air batteries (ZABs) are a significant candidate in energy conversion and storage, relying on bifunctional catalysts toward oxygen reduction/evolution reactions (ORR/OER). Achieving fast-charging feature necessitates decreased resistance, activation, and concentration polarizations during OER. Herein, we present a well-controlled catalyst consisting of NiFe2O4 nanorod modified CoNC nanosheet (NiFeONR@CoNCNS), creating an axial interfacial Co-O-Fe bridge. The conductive CoNCNS substrate reduces resistance polarization and meanwhile triggers Co-O-Fe bridge formation, which can activate Ni sites and reduce activation polarization. The controlled NiFeONR facilitates oxygen removal and decreases the concentration of polarization. Consequently, the NiFeONR@CoNCNS catalyst affords a good fast-charging performance in the corresponding ZABs. Importantly, given the strong affinity between NiFeONR and CoNCNS via the Co-O-Fe bridge, a good stability is presented in fast-charging ZABs, e.g., over 1000 h of operation at both 10 mA cm-2 and 20 mA cm-2, and approaching 350 h at 50 mA cm-2.
Chen et al. (Wed,) studied this question.