Bifunctional Oxygen Electrocatalysis Research Articles

A ZnFeNiCoCr high-entropy alloy for efficient bifunctional oxygen electrocatalysis

A ZnFeNiCoCr high-entropy alloy for efficient bifunctional oxygen electrocatalysis

Enabling High‐Rate and Long‐Cycling Zinc–Air Batteries with a ΔE = 0.56 V Bifunctional Oxygen Electrocatalyst

AbstractZn–air batteries (ZABs) are promising next‐generation energy storage devices due to their low cost, intrinsic safety, and environmental benignity. However, the sluggish kinetics of the cathodic reactions severely limits the ZAB performances in practical use, calling for high‐efficiency bifunctional oxygen reduction and evolution electrocatalysts. Herein, an ultrahigh‐active bifunctional electrocatalyst is developed with a record‐low ΔE of 0.56 V, significantly outperforming the noble‐metal‐based benchmark (Pt/C+Ir/C, ΔE = 0.77 V) and many other reported bifunctional electrocatalysts (mostly ΔE ≥ 0.60 V). The nanoscale composite of Fe‐based single‐atom sites and nanosized layered double hydroxides endows the bifunctional electrocatalyst with high conductivity and a large active surface that afford strengthened electron conduction and ion transport pathways. Furthermore, a remarkable improvement in stability is realized following the current division principle. ZABs with the bifunctional electrocatalyst deliver a high peak power density of 198 mW cm−2 and excellent cycling durability for over 6000 cycles. Moreover, ampere‐hour‐scale ZABs are constructed and cycled under 1.0 A and 1.0 Ah conditions. This work breaks the activity record for bifunctional oxygen electrocatalysis and expands the potential of ZABs for sustainable energy storage.

FeCo Bimetallic ZIF Derivatives decorated with CoFe-LDH to Promote Bifunctional Oxygen Electrocatalysis Activation.

Reasonably screening the targeted oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) constituents and constructing high-efficiency and stabilized ORR/OER bifunctional electrocatalysts are pivotal for the advancement of rechargeable zinc-air batteries (ZABs). Here, CoFe layered double hydroxide (CoFe-LDH) nanosheets are deposited on nitrogen-doped graphite-carbon polyhedra with FeCo alloy nanoparticles (FeCo/LDH-NGCP). Due to the synergic effect between FeCo-NGCP, CoFe-LDH and FeCo/LDH-NGCP, the electrocatalyst with the abundant and accessible active sites can provide good charge/mass transfer, and thus shows wonderful ORR and OER bifunctional electrocatalytic performance. In ORR tests, FeCo/LDH-NGCP catalyst displays larger half-wave potential (E1/2, 0.89 V vs. 0.85 V), higher limiting current density (JL, 5.91 mA/cm2 vs. 5.14 mA/cm2) and better stability than commercial Pt/C. As for OER, FeCo/LDH-NGCP possesses a smaller overpotential (η) of 299.6 mV at a current density of 10 mA/cm2 and more durable stability than commercial RuO2 (330.6 mV). Furthermore, in ZAB tests, the cycling stability of ZAB-FeCo/LDH-NGCP (over 470 h) outperforms the ZAB-Pt/C+RuO2 (92 h) with commercial electrocatalyst (Pt/C+RuO2). Therefore, the FeCo/LDH-NGCP catalyst offers a new perspective to construct ZABs bifunctional catalysts and their commercial application in ZABs.

Dual electric field effects boost bifunctional oxygen electrocatalysis

Regulation of the surface microenvironment is crucial for the development of highly active and durable OER/ORR bifunctional catalysts. In this study, a bifunctional m-CoSx@NSC electrocatalyst with dual electric field effects was designed and fabricated by synchronous pyrolysis of organic sulfur-rich cobalt compounds (Co-DC) and melem. The introduction of nitrogen-rich melem effectively induced the conversion of Co-DC and the growth of tentacles to form a hierarchical carbon skeleton. The interfacial micro-electric field between the carbon layer and CoSx active species improves the intrinsic activity and stability of m-CoSx@NSC. Finite element method simulation and in-situ measurements proved that the tentacle-induced external local electric field promotes the formation of Co(OH)2/CoOOH intermediates and mass transfer, thus accelerating the catalytic reaction kinetics. Through the synergistic effect of dual electric fields, the m-CoSx@NSC catalyst demonstrated a low overpotential of 340 mV for OER and a high half-wave potential of 0.85 V for ORR. Furthermore, the m-CoSx@NSC-based ZAB exhibited an open-circuit voltage of 1.42 V, a maximum power density of 87.38 mW cm−2, a specific capacity of 876.17 mAh gZn−1, and a cycling performance of 700 cycles. The synergistic regulation of the internal and external microenvironments provides a novel insight to improve the catalytic reaction kinetics of OER/ORR.

Deciphering the Synergistic Effect in Strong Metal–Support Interaction toward Surface Reconstruction of Prussian Blue Analogue-Based Pre-Catalysts for Boosted Bifunctional Oxygen Electrocatalysis via Operando Raman Spectroscopy

Deciphering the Synergistic Effect in Strong Metal–Support Interaction toward Surface Reconstruction of Prussian Blue Analogue-Based Pre-Catalysts for Boosted Bifunctional Oxygen Electrocatalysis via Operando Raman Spectroscopy

Rationalizing the catalytic surface area of oxygen vacancy‐enriched layered perovskite LaSrCrO4 nanowires on oxygen electrocatalyst for enhanced performance of Li–O2 batteries

AbstractEfficient electrocatalysis at the cathode is crucial to addressing the limited stability and low rate capability of Li−O2 batteries. This study examines the kinetic behavior of Li−O2 batteries utilizing layered perovskite LaSrCrO4 nanowires (NWs) composed of lower oxidation states. Layered perovskite LaSrCrO4 NWs exhibited improved rate capability over a wide range of current densities and longer cycle life in Li−O2 batteries than V‐based layered perovskite (LaSrVO4) and simple perovskite (La0.8Sr0.2CrO3) NWs. X‐ray photoelectron spectroscopy and electrochemical surface area analyses showed that the observed performance variations primarily stemmed from active sites such as oxygen vacancies. In situ Raman analysis showed that these active sites significantly modulate the kinetics of oxygen reduction and evolution, which are related to LiO2 intermediate adsorption. Electrochemical impedance spectroscopy showed that the active sites in layered perovskite LaSrCrO4 NWs contributed to their high charge transfer capability and reduced polarization. This study presents an appealing method for the precise fabrication and analysis of Cr‐based layered perovskites, aimed at achieving highly efficient and stable bifunctional oxygen electrocatalysis.

Copper dual-doping strategy of porous carbon nanofibers and nickel fluoride nanorods as bi-functional oxygen electrocatalysis for effective zinc-air batteries

Designing and developing efficient, low-cost bi-functional oxygen electrocatalysts is essential for effective zinc-air batteries. In this study, we propose a copper dual-doping strategy, which involves doping both porous carbon nanofibers (PCNFs) and nickel fluoride nanoparticles with copper alone, successfully preparing copper-doped nickel fluoride (NiF2) nanorods and copper nanoparticles co-modified PCNFs (Cu@NiF2/Cu-PCNFs) as an efficient bi-functional oxygen electrocatalyst. When copper is doped into the PCNFs in the form of metallic nanoparticles, the doped elemental copper can improve the electronic conductivity of composite materials to accelerate electron conduction. Meanwhile, the copper doping for NiF2 can significantly promote the transformation of nickel fluoride nanoparticles into nanorod structures, thus increasing the electrochemical active surface area and enhancing mass diffusion. The Cu-doped NiF2 nanorods also possess an optimized electronic structure, including a more negative d-band center, smaller bandgap width and lower reaction energy barrier. Under the synergistic effect of these advantages, the obtained Cu@NiF2/Cu-PCNFs exhibit outstanding bi-functional catalytic performances, with a low overpotential of 0.68 V and a peak power density of 222 mW cm−2 in zinc-air batteries (ZABs) and stable cycling for 800 h. This work proposes a one-step way based on the dual-doping strategy, providing important guidance for designing and developing efficient catalysts with well-designed architectures for high-performance ZABs.

Layered Porous Ring-Like Carbon Network Protected FeNi Metal Atomic Pairs for Bifunctional Oxygen Electrocatalysis and Rechargeable Zn-Air Batteries.

Bimetallic atom catalysts exhibit ultra-high oxygen electrocatalytic activity by harnessing mutual promotion and synergistic effects between adjacent metal active centers, surpassing the performance of single metal atomic catalysts. Herein, FeNi atom pairs protected by hierarchical porous annular carbon grids (P-FeNi-NPC) are introduced using a mediator-assisted MOFs-derived strategy. The introduction of the multi-block copolymer P123 ensures the uniform confinement and dispersion of metal ions, followed by thermal decomposition to form a "planetary-ring-like" carbon framework that anchors the bimetallic atomic pairs in the active region. The homogeneous distribution of adjacent Fe-N4 and Ni-N4 active sites significantly enhances catalytic activity and stability. Leveraging unique electronic and geometric structures, the resulting P-FeNi-NPC catalyst demonstrates exceptional ORR and OER activities with an ΔE value of 0.705 (E1/2 = 0.845V, Ej = 10 = 1.55V). Theoretical calculations unveil that FeNi bimetallic sites loaded on nitrogen-doped carbon frameworks with specific curvature effectively modulate the energy of d-band centers, thus balancing the free energy of oxygen-containing intermediates. This study presents a novel and versatile approach for synthesizing advanced bifunctional catalysts, poised to drive the future development of Zn-air batteries.

Tailoring Single‐Atom Coordination Environments in Carbon Nanofibers via Flash Heating for Highly Efficient Bifunctional Oxygen Electrocatalysis

The rational design of carbon‐supported transition metal single‐atom catalysts necessitates precise atomic positioning within the precursor. However, structural collapse during pyrolysis can occlude single atoms, posing significant challenges in controlling both their utilization and coordination environment. Herein, we present a surface atom adsorption‐flash heating (FH) strategy, which ensures that the pre‐designed carbon nanofiber structure remains intact during heating, preventing unforeseen collapse effects and enabling the formation of metal atoms in nano‐environments with either tetra‐nitrogen or penta‐nitrogen coordination at different flash heating temperatures. Theoretical calculations and in situ Raman spectroscopy reveal that penta‐nitrogen coordinated cobalt atoms (Co‐N5) promote a lower energy pathway for oxygen reduction and oxygen evolution reactions compared to the commonly formed Co‐N4 sites. This strategy ensures that Co‐N5 sites are fully exposed on the surface, achieving exceptionally high atomic utilization. The turnover frequency (65.33 s‐1) is 47.4 times higher than that of 20% Pt/C under alkaline conditions. The porous, flexible carbon nanofibers significantly enhance zinc‐air battery performance, with a high peak power density (273.8 mW cm‐2), large specific capacity (784.2 mA h g‐1), and long‐term cycling stability over 600 h. Additionally, the flexible fiber‐shaped zinc‐air battery can power wearable devices, demonstrating significant potential in flexible electronics applications.

Tailoring Single-Atom Coordination Environments in Carbon Nanofibers via Flash Heating for Highly Efficient Bifunctional Oxygen Electrocatalysis.

The rational design of carbon-supported transition metal single-atom catalysts necessitates precise atomic positioning within the precursor. However, structural collapse during pyrolysis can occlude single atoms, posing significant challenges in controlling both their utilization and coordination environment. Herein, we present a surface atom adsorption-flash heating (FH) strategy, which ensures that the pre-designed carbon nanofiber structure remains intact during heating, preventing unforeseen collapse effects and enabling the formation of metal atoms in nano-environments with either tetra-nitrogen or penta-nitrogen coordination at different flash heating temperatures. Theoretical calculations and in situ Raman spectroscopy reveal that penta-nitrogen coordinated cobalt atoms (Co-N5) promote a lower energy pathway for oxygen reduction and oxygen evolution reactions compared to the commonly formed Co-N4 sites. This strategy ensures that Co-N5 sites are fully exposed on the surface, achieving exceptionally high atomic utilization. The turnover frequency (65.33 s-1) is 47.4 times higher than that of 20 % Pt/C under alkaline conditions. The porous, flexible carbon nanofibers significantly enhance zinc-air battery performance, with a high peak power density (273.8 mW cm-2), large specific capacity (784.2 mAh g-1), and long-term cycling stability over 600 h. Additionally, the flexible fiber-shaped zinc-air battery can power wearable devices, demonstrating significant potential in flexible electronics applications.

Structurally optimized rosette-like microspheres carbon with Fe-Ni single atom sites for bifunctional oxygen electrocatalysis in Zinc-Air batteries

Developing a secure and effective bifunctional oxygen catalyst for the ORR and OER is still a significant obstacle in the design of rechargeable zinc-air batteries. Here, a hollow rose-shaped bifunctional electrocatalyst is synthesized with an sacrificial template strategy (FeNi-NC). X-ray absorption fine structure analysis reveals the FeNi-NC catalyst contains FeN4 and NiN4 active sites as well as FeNi3 alloy. This hollow, flower-like structure performs low density, large specific surface area, and high permeability. Its inner cavities not only provide additional triple-phase interfaces to accelerate the reduction and oxidation of O2, but also enhance the diffusion of reactants on the catalyst. By controlling the input of Fe and nickel metal salts, the dispersion of active sites can be effectively tuned. Owing to the large number of exposed active sites on the carbon nanosheets, the synthesized FeNi-NC catalysts exhibit high electrocatalytic activity in both ORR (E1/2 = 0.852 V) and OER (ηj=10 = 359 mV). The construction of rechargeable zinc-air batteries resulted in a high power density of 135.78 mW cm−2, a better specific capacitance of 726.9 Wh kgZn−1 and 210 h enduring durability. More importantly, density functional theory (DFT) calculations indicate that the electronic interactions between Fe/Ni and nitrogen-doped carbon matrices play a pivotal role in enhancing the electrocatalytic performance of functional groups. These interactions effectively disrupt the electronic neutrality of carbon atoms, thereby accelerating the kinetics of the reaction. This research provides a new method for the preparation of single atom catalysts with bifunctional activities.

Ru Decoration By PEALD for Bifunctional Oxygen Electrocatalysis in Solid Oxide Cells

Solid oxide cells (SOCs) are electrochemical devices that have garnered significant attention due to their high efficiency, fuel flexibility, and reversibility for operation in both fuel cell and the electrolysis modes. However, the relatively high operating temperature (typically > 800 °C) required presents various challenges such as fast degradation, high operating costs, and slow start-up. To overcome these issues, significant efforts have been made to decrease the operating temperature, but this causes a dramatic decrease in performance due to the low catalytic activity of typical electrode materials. One strategy to increase the catalytic activity is to introduce highly active nanoparticles onto a conventional electrode backbone, but while noble metals such as Ru and Ir have been utilized as oxygen evolution reaction (OER) catalysts, their widespread application in SOECs is hindered by their high cost and limited availability.In this presentation, we demonstrate a highly effective approach to enhance air electrode performance through the deposition of an ultrathin layer of metallic Ru, as thin as ∼7.5 Å, onto (La0.6Sr0.4)0.95Co0.2Fe0.8O3-δ (LSCF) using plasma-enhanced atomic layer deposition (PEALD). The Ru-decorated cell exhibited a current density of 656 mA cm–2 at 1.3 V, significantly outperforming a bare cell (440 mA cm–2 at 1.3 V). The decorated cell also showed a largely enhanced cell durability, which is ascribed to the beneficial role of SrRuO3 that emerges from the reaction between PEALD-based Ru and surface-segregated Sr species, in suppressing Sr segregation and maintaining favorable oxygen desorption kinetics. Further, the PEALD Ru coating on LSCF also reduces the resistance to the oxygen reduction reaction (ORR), highlighting the bifunctional electrocatalytic activities for reversible fuel cells. When the LSCF electrode of a test cell is decorated with ∼7.5 Å of the Ru overcoat and tested in fuel cell mode at 700 °C, this results in a current density of 656 mA cm-2 at 1.3 V in electrolysis mode and a peak power density of 803 mW cm-2, corresponding to an enhancement of 49.1% and 31.9%, respectively, compared to the pristine cell.

Engineering of active site coupling to facilitate interatomic charge transfer for bifunctional oxygen electrocatalysis

Interatomic charge transfer emerges as a robust technique for enhancing catalytic efficacy in key energy reactions, specifically the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Despite its potential, advancing simultaneous improvements in reversible oxygen catalysis pose considerable challenges. Herein, we detailed an active site coupling engineering method to create a CoCu@NSC bifunctional oxygen electrode. In this configuration, OER-active Cu sites were alloyed with ORR-active Co within a N/S-doping carbon nanobox. This arrangement yielded a half-wave potential of 0.924 V for ORR, alongside an overpotential of η10 = 356 mV for OER. The fabricated CoCu@NSC cathode yielded a discharge capacity of 768 mAh/gZn, a peak power density of 295 mW/cm2, and extensive cycling durability. Work function assessments indicated that the chemical integration of Co and Cu components at the atomic level promoted interfacial charge redistribution, effectively optimizing the adsorption-desorption dynamics of intermediates at the active sites, thereby substantially enhancing the catalytic performance for both OER and ORR. Additionally, doping with N/S species enhanced the conductivity of the hollow carbon matrix, facilitating more effective mass and charge transport pathways. These insights illuminate a compelling approach for the design and synthesis of effective bifunctional oxygen electrodes that is pivotal for advanced energy storage advice.

Facilitating charge transfer via a Semi-Coherent Fe(PO3)2-Co2P2O7 heterointerface for highly efficient Zn-Air batteries

Developing reversible oxygen electrodes for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for achieving high-performance rechargeable Zn-air batteries (ZABs). This study introduced an nitrogen-doped carbon confined with a semi-coherent Fe(PO3)2-Co2P2O7 heterojunction for bifunctional oxygen electrocatalysis. This nanocomposite yielded an ORR half-wave potential of 0.908 V and an OER overpotential of 291 mV at 10 mA/cm2. ZABs incorporating this catalyst yielded impressive performance, including a peak power density of 203 mW/cm2, a specific capacity of 737 mAh/gZn, and promoted stability. Both experimental and theoretical simulations demonstrated that the unique electric field between Fe(PO3)2 and Co2P2O7 promoted efficient charge transport across the heterointerface. This interaction likely modulated the d-band center of the heterojunction, expedite the desorption of oxygen intermediates, thus improving oxygen catalysis and, consequently, ZAB performance. This work illustrates a significant design principle for creating efficient bifunctional catalysts in energy conversion technologies.

Coaxial MWCNTs/Co-N@N-doped carbon hierarchical porous nanowires as durable air electrode for aqueous Zn-air batteries

Aqueous zinc-air batteries can replace lithium-ion batteries to be used in the future large-scale application. However, efficient bifunctional oxygen catalyst used in air electrode for aqueous zinc-air batteries generally still meet serious challenge. The catalytic activity and stability of air electrode still far from satisfactory. In this work, we designed a series of coaxial MWCNTs/Co-N@N-doped carbon hierarchical porous nanowires (MWCNTs/Co-N@NC) as bifunctional oxygen electrocatalyst with different Co contents. The Co content can facilitate to form the Co-Nx and pyridinic-N to boost the bifunctional oxygen electrocatalysis. The optimal MWCNTs/Co-N@NC-1 delivers superior electrocatalysis for oxygen reduction reaction (ORR) with E1/2 of 0.86 V (vs. RHE) and rational performance for oxygen evolution reaction (OER) with Ej=10 of 1.59 V (vs. RHE) in 0.1 mol/L KOH. In addition, the MWCNTs/Co-N@NC-1-based Zn-air battery exhibits the discharge capacity of 898.84 mAh gZn−1 and a optimal power density of 158.1 mW cm−2 with cycling stability for 300 h. This study provides a strategy to construct robust durability air electrode for aqueous zinc-air batteries.

Electron Spin Broken-Symmetry of Fe-Co Diatomic Pairs to Promote Kinetics of Bifunctional Oxygen Electrocatalysis for Zinc-Air Batteries.

Designing bifunctional catalysts to reduce the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) reaction barriers while accelerating the reaction kinetics is perceived to be a promising strategy to improve the performance of Zinc-air batteries. Unsymmetric configuration in single-atom catalysts has attracted attention due to its unique advantages in regulating electron orbitals. In this work, a seesaw effect in unsymmetric Fe-Co bimetallic monoatomic configurations is proposed, which can effectively improve the OER/ORR bifunctional activity of the catalyst. Compared with the symmetrical model of Fe-Co, a strong charge polarization between Co and Fe atoms in the unsymmetric model is detected, in whom the spin-down electrons around Co atoms are much higher than those spin-up electrons. The seesaw effect occurred between Co atoms and Fe atoms, resulting in a negative shift of the d-band center, which means that the adsorption of oxygen intermediates is weakened and more conducive to their dissociation. The optimized reaction kinetics of the catalyst leads to excellent performance in ZABs, with a peak power density of 215mW cm-2 and stable cycling for >1300 h and >4000 cycles. Flexible Zinc-air batteries have also gained excellent performance to demonstrate their potential in the field of flexible wearables.

Asymmetrical Ru–O–Mn Bridge Active Sites Fully Decouple Bifunctional Oxygen Electrocatalysis for Rechargeable Zinc-Air Batteries

Asymmetrical Ru–O–Mn Bridge Active Sites Fully Decouple Bifunctional Oxygen Electrocatalysis for Rechargeable Zinc-Air Batteries

Guanine-derived core-shell FeCo alloy confined in graphene-like N-doped carbon as efficient bifunctional oxygen electrocatalysts for rechargeable Zn-air batteries

Maximization the synergistic effect of each component in transition metal-carbon complexes is expected to improve the bifunctional oxygen electrocatalysis for rechargeable Zn-air batteries but is still challenging. Herein, nucleobase guanine is employed as a supramolecular precursor to generate the core (FeCo alloy)-shell (carbon) structure embedded in ultrathin graphene-like nitrogen-doped carbon nanosheets (FeCo@NCNSs) via a confinement pyrolysis strategy. Thanks to the generated core-shell structure and bimetallic synergistic effect, the as-prepared FeCo@NCNSs exhibits excellent electrochemical performance in both oxygen reduction reaction and oxygen evolution reaction. As a result, when served as the bifunctional air electrode for a practical Zn-air battery, FeCo@NCNSs exhibits a higher open-circuit voltage (1.553 V) and peak power density (197.30 mW cm−2), as well as the greatly improved long-term cyclic stability compared to the noble metal benchmarks. This work provides a promising approach to integrate various active sites for bifunctional oxygen electrocatalysis and inspires the exploration of simple but efficient electrocatalysts for energy storage and conversion.

Highly Reversible Zn-Air Batteries Enabled by Tuned Valence Electron and Steric Hindrance on Atomic Fe-N4-C Sites.

The bifunctional oxygen electrocatalyst is the Achilles' heel of achieving robust reversible Zn-air batteries (ZABs). Herein, durable bifunctional oxygen electrocatalysis in alkaline media is realized on atomic Fe-N4-C sites reinforced by NixCo3-xO4 (NixCo3-xO4@Fe1/NC). Compared with that of pristine Fe1/NC, the stability of the oxygen evolution reaction (OER) is increased 10 times and the oxygen reduction reaction (ORR) performance is also improved. The steric hindrance alters the valence electron at the Fe-N4-C sites, resulting in a shorter Fe-N bond and enhanced stability of the Fe-N4-C sites. The corresponding solid-state ZABs exhibit an ultralong lifespan (>460 h at 5 mA cm-2) and high rate performance (from 2 to 50 mA cm-2). Furthermore, the structural evolution of NixCo3-xO4@Fe1/NC before and after the OER and ORR as well as charge-discharge cycling is explored. This work develops an efficient strategy for improving bifunctional oxygen electrocatalysis and possibly other processes.

P-Bridging Asymmetry Diatomic Catalysts Sites Drive Efficient Bifunctional Oxygen Electrocatalysis for Zinc-Air Batteries.

Rechargeable zinc-air batteries (ZABs) rely on the development of high-performance bifunctional oxygen electrocatalysts to facilitate efficient oxygen reduction/evolution reactions (ORR/OER). Single-atom catalysts (SACs), characterized by their precisely defined active sites, have great potential for applications in ZABs. However, the design and architecture of atomic site electrocatalysts with both high activity and durability present significant challenges, owing to their spatial confinement and electronic states. In this study, a strategy is proposed to fabricate structurally uniform dual single-atom electrocatalyst (denoted as P-FeCo/NC) consisting of P-bridging Fe and Co bimetal atom (i.e., Fe-P-Co) decorated on N, P-co-doped carbon framework as an efficient and durable bifunctional electrocatalyst for ZABs. Experimental investigations and theoretical calculations reveal that the Fe-P-Co bridge-coupling structure enables a facile adsorption/desorption of oxygen intermediates and low activation barrier. The resultant P-FeCo/NC exhibits ultralow overpotential of 340mV at 10mA cm-2 for OER and high half-wave potential of 0.95V for ORR. In addition, the application of P-FeCo/NC in rechargeable ZABs demonstrates enhanced performance with maximum power density of 115mW cm-2 and long cyclic stability, which surpass Pt/C and RuO2 catalysts. This study provides valuable insights into the design and mechanism of atomically dispersed catalysts for energy conversion applications.