Constructing Co–O–Fe Bridge To Accelerate Axial Charge and Mass Transfer for Fast-Charging Zinc-Air Batteries

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 NiFe 2 O 4 nanorod modified CoNC nanosheet (NiFeO NR @CoNC NS ), creating an axial interfacial Co–O–Fe bridge. The conductive CoNC NS substrate reduces resistance polarization and meanwhile triggers Co–O–Fe bridge formation, which can activate Ni sites and reduce activation polarization. The controlled NiFeO NR facilitates oxygen removal and decreases the concentration of polarization. Consequently, the NiFeO NR @CoNC NS catalyst affords a good fast-charging performance in the corresponding ZABs. Importantly, given the strong affinity between NiFeO NR and CoNC NS 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 .