Dual‐Confined Bead‐Like CoSe2@NC@NCNFs Bifunctional Catalyst Boosting Rechargeable Zinc‐Air Batteries†

Abstract

Comprehensive SummaryRationally developing efficient and durable bifunctional catalysts toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critical for rechargeable zinc‐air batteries (ZABs). Herein, a bead‐like CoSe2@NC@NCNFs bifunctional catalyst was designed and fabricated by confining cubic CoSe2 nanoparticles to three‐dimensional (3D) porous MOFs‐derived nitrogen‐doped carbon (NC) and one‐dimensional (1D) N‐doped carbon nanofibers (NCNFs) through a facile encapsulate strategy. The 1D/3D continuous network structure contributes to the improvement of specific surface area and electronic conductivity, while the strong synergistic effect between CoSe2 sites and Co‐Nx‐C sites can effectively enhance electron/mass transfer and reduce the diffusion resistance. The as‐constructed CoSe2@NC@NCNFs catalyst exhibits high catalytic activity and stability toward ORR/OER with a high half‐wave potential of 0.80 V (vs. RHE) in ORR and a low overpotential of 280 mV at 10 mA·cm−2 in OER. More encouragingly, the rechargeable ZABs with CoSe2@NC@NCNFs cathode deliver high peak power densities (126.8 mW·cm−2), large specific capacities (763.1 mA·h·g−1), and robust charge‐discharge cycling stability over 240 cycles. This study provides a facile strategy for designing efficient bifunctional catalysts for rechargeable energy conversion applications.