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 exhibit 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.This article is protected by copyright. All rights reserved.

Free‐Standing Multiscale Porous High Entropy NiFeCoZn Alloy as the Highly Active Bifunctional Electrocatalyst for Alkaline Water Splitting

“…In the Zn 2p spectra (Figure 4h), the peak at 1021.3 eV comes from the metallic Zn with a positive shift of ~0.13 eV compared with pure Zn. [ 39‐40 ] Based on the results above, the binding energies of Ni, Fe, and Co all slightly shift to the lower value, while that of Zn shifts to the larger value, suggesting that the formation of NiFeCoZn HEA causes an intense electron transfer among multiple elements. For the O 1s core level region (Figure 4i), the peak located at 529.18, 530.98, and 532.58 eV can be attributed to the metal‐oxygen bond, metal‐hydroxyl bond, and the adsorbed water, respectively, [ 26,41‐42 ] further confirming the existence of surface metal oxides and hydroxides.…”

Self-Vulcanized Heterogeneous Interface Derived from Organic Cobalt Residue for Rechargeable Zinc–Air Batteries

“…Advanced energy storage and conversion technologies, such as solar cells, Li-ion batteries, supercapacitors, and metal-air batteries, have recently garnered significant global attention owing to limited fossil fuel reserves and severe environmental degradation. − Among these, rechargeable zinc–air batteries (ZABs) stand out because of their high energy density, low price, environmental protection, and high security, making them viable options for real-world use. − However, existing noble metal catalysts, such as Pt/C, IrO x , and RuO x , for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are expensive and scarce, significantly hindering their large-scale application as air cathodes. , Moreover, these catalysts generally have a single catalytic activity and lack stability during charging and discharging cycles. , Therefore, for ZABs to be used in real-world applications, bifunctional oxygen electrocatalysts that are highly effective, long lasting, and reasonably priced must be developed.…”

“…8−11 However, existing noble metal catalysts, such as Pt/C, IrO x , and RuO x , for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are expensive and scarce, significantly hindering their large-scale application as air cathodes. 12,13 Moreover, these catalysts generally have a single catalytic activity and lack stability during charging and discharging cycles. 14,15 Therefore, for ZABs to be used in real-world applications, bifunctional oxygen electrocatalysts that are highly effective, long lasting, and reasonably priced must be developed.…”