Rechargeable Zn-air Batteries Research Articles

Recent Achievements in Heterogeneous Bimetallic Atomically Dispersed Catalysts for Zn-Air Batteries: A Minireview.

Rechargeable Zn-air batteries (ZABs) hold promise as the next-generation energy-storage devices owing to their affordability, environmental friendliness, and safety. However, cathodic catalysts are easily inactivated in prolonged redox potential environments, resulting in inadequate energy efficiency and poor cycle stability. To address these challenges, anodic active sites require multiple-atom combinations, that is, ensembles of metals. Heterogeneous bimetallic atomically dispersed catalysts (HBADCs), consisting of heterogeneous isolated single atoms and atomic pairs, are expected to synergistically boost the cyclic oxygen reduction and evolution reactions of ZABs owing to their tuneable microenvironments. This minireview revisits recent achievements in HBADCs for ZABs. Coordination environment engineering and catalytic substrate structure optimization strategies are summarized to predict the innovation direction for HBADCs in ZAB performance enhancement. These HBADCs are divided into ferrous and nonferrous dual sites with unique microenvironments, including synergistic effects, ion modulation, electronic coupling, and catalytic activity. Finally, conclusions and perspectives relating to future challenges and potential opportunities are provided to optimise the performance of ZABs.

Carbothermal Reduction-Assisted Synthesis of a Carbon-Supported Highly Dispersed PtSn Nanoalloy for the Oxygen Reduction Reaction.

Exploring high-performance and low-platinum-based electrocatalysts to accelerate the oxygen reduction reaction (ORR) at the air cathode of zinc-air batteries remains crucial. Herein, by combining electroless deposition and carbothermal reduction, a nitrogen-doped carbon-supported highly dispersed PtSn alloy nanocatalyst (PtSn/NC) was prepared for a high-efficiency ORR process. Electrochemical measurements show that PtSn/NC exhibits excellent electrocatalytic ORR activity with a half-wave potential of 0.850 V versus reversible hydrogen electrode (RHE), which is higher than that of commercial Pt/C (0.815 V). The PtSn/NC-based (20 μgPt cm-2) rechargeable Zn-air battery exhibited astonishing performance with a maximum power density of up to 150.1 mW cm-2, as well as excellent rate performance and charge/discharge stability. Physical characterization reveals that carbothermal reduction could compel the transformation of Sn oxide into metallic Sn, which then alloys with the deposited Pt atoms to form the PtSn nanoalloy, in which electrons are transferred from Sn atoms to neighboring Pt atoms, thereby improving the ability of Pt-based active sites to catalyze the ORR process in PtSn/NC by optimizing the unoccupied d-band of Pt atoms. This work provides a reliable and innovative route for the rational design of highly dispersed Pt-based alloy ORR electrocatalysts.

High activity of cobalt-atomically dispersed catalyst on mesoporous carbon for rechargeable Zn-air batteries via effective removal of the hard template

The use of oxygen from air in Zn-air batteries requires the smart design of materials with bifunctional activity for oxygen reduction and evolution reactions (ORR/OER), and with a porous structure to facilitate the diffusion of oxygen gas to active sites. Kit-6 template-assisted porous structures have been proposed to this end; however, traditional methods for the removal of Kit-6 templates are highly aggressive and environmentally harmful. In this study, we present the synthesis of a cobalt atomically dispersed catalyst (Co-ADC) with interlayer engineering using mesoporous Kit−6 templates, focusing on two removal strategies: sodium hydroxide (0.5, 1, and 2 M) and hydrofluoric acid (15, 30, and 45 %). Physicochemical results indicated that Co-ADC-containing nanoparticles were obtained using the proposed methodology, while the use of HF promoted the loss of cobalt in the catalyst. During the activity evaluation for the ORR, and it was found that 0.5 M NaOH and HF at 15 % displayed similar activity, which could be related to the effect of carbon material as co-catalyst, but the first enabled a close 4e- pathway, and thus, the Co-ADC presented a ΔEOER-ORR of 640 mV. This optimized ADC displayed improved functionality owing to diffusion improvements by the mesoporous structure, presenting a maximum power density of 130.6 mW cm−2 and 30 % higher specific activity than the Pt+IrO2/C reference material. Rechargeability was evaluated, yielding a ΔV=0.87 V at 5.175 mA cm−2 with a round-trip efficiency of 57.5 %. Nonetheless, the optimized material presented higher rechargeability, displaying no significant round-trip changes after 100 cycles, while Pt+IrO2/C presented changes due to OER issues after only 48 cycles.

Heterointerface engineering of yolk-shell-structured Mn2O3/RuO2 for boosting oxygen electrocatalysis in rechargeable liquid and flexible zinc-air batteries

Rational construction of high-efficient bifunctional oxygen electrocatalysts is of crucial significance for rechargeable Zn-air batteries (ZABs). Here, the yolk-shell-structured Mn2O3/RuO2 heterojunction is purposely constructed via the Kirkendall effect as a robust bifunctional oxygen electrocatalyst for simultaneously driving oxygen evolution and reduction reactions (OER and ORR). The strong interactions between Mn2O3 and RuO2 induces the surface reconstruction that brings the electronic transfer from Mn to Ru, and the changes of coordination environments of metal atoms. Meanwhile, the yolk-shell structure enables maximum contact of the active sites with the electrolyte and prevents the dissolution and peroxidation of active species. As a result, the yolk-shell-structured Mn2O3/RuO2 shows an outstanding bifunctional activity with a very low potential gap of ΔE = 0.60 V. Moreover, the ZABs assembled with Mn2O3/RuO2 render a large open circuit voltage of 1.53 V, a high specific capacity of 742.1 mA h g−1 and an exceptional cycling stability over 850 h that significantly outperforms those of Pt/C+RuO2-based ZABs. Moreover, the self-made flexible solid-state ZAB with Mn2O3/RuO2 cathode also shows good charge–discharge reversibility and flexibility at different bending angles. This work provides a feasible method for the design of efficient oxygen electrocatalysts to promote the practical application of ZABs.

MnO2/rGO bifunctional catalyst and support materials for gel polymer electrolyte based Zn-air batteries

A high-performance and long-lasting, rechargeable Zn-air battery requires a reliable and effective bifunctional catalyst material to facilitate the oxygen reduction and oxygen evolution reactions during the battery operation. Manganese oxide (MnO2) is a promising non-precious perspective due to its multivalency and various polymorphic structures that effectively catalyze oxygen evolution and reduction. In the present work, MnO2 nanowires (NWs) have been integrated with over-reduced graphene oxide (rGO) in various concentrations via a facile hydrothermal route. The synthesized materials, tested in lab-made zinc-air battery devices fabricated using gel polymer electrolyte, exhibit a significant enhancement in the performance and 2-3 times the cycle life compared to the bare MnO2. The ZAB device was tested for galvanostatic charge-discharge technique, and results exhibit a cycle life of 165 h (495 cycles@20 minutes per cycle) when discharged up to 1.0 V at a current density of 5.2 mA/cm2 and displayed a capacity of 731 mAh/gZn. Reduced graphene oxide acts as a support material that enhances the conductivity and surface area of the active material and also provides active sites for catalysis. This work signifies the importance of the engineering of the catalyst, support material, and additives, as slight changes may result in a significant enhancement in the cycle life. The appropriate composition of catalyst and support material and a compatible gel polymer electrolyte facilitates the fabrication of flexible zinc-air batteries for various applications.

Unveiling the Dynamic Evolution of Catalytic Sites in N-Doped Leaf-like Carbon Frames Embedded with Co Particles for Rechargeable Zn-Air Batteries.

The advancement of cost-effective, high-performance catalysts for both electrochemical oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) is crucial for the widespread implementation of metal-air batteries. In this research, we fabricated leaf-like N-doped carbon frames embedded with Co nanoparticles by pyrolyzing a ZIF-L/carbon nanofiber (ZIF-L/CNF) composite. Consequently, the optimized ZIF-L/CNF-700 catalyst exhibit exceptional catalytic activities in both ORRs and OERs, comparable to the benchmark 20 wt% Pt/C and RuO2. Addressing the issue of diminished cycle performance in the Zn-air battery cycle process, further detailed investigations into the post-electrolytic composition reveal that both the carbon framework and Co nanoparticles undergo partial oxidation during both OERs and ORRs. Owing to the varying local pH on the catalyst surface due to the consumption and generation of OH- by OERs and ORRs, after OERs, the product is reduced-size Co particles, while after ORRs, the product is outer-layer Co(OH)2-enveloping Co particles.

Catalyst–Support Interaction in Polyaniline-Supported Ni3Fe Oxide to Boost Oxygen Evolution Activities for Rechargeable Zn-Air Batteries

HighlightsNi3Fe oxide, with an average size of 3.5 ± 1.5 nm, was successfully deposited onto polyaniline (PANI) support through a solvothermal strategy followed by calcination.The catalyst–support interaction between Ni3Fe oxide and PANI can enhance the Ni-O covalency via the interfacial Ni-N bond.Ni3Fe oxide/PANI-assembled Zn-air batteries achieve superior cycling life for over 400 h at 10 mA cm−2 and a low charge potential of around 1.95 V.

Molten-Salt-Assisted Fabrication of Defect-Rich 2D/3D Nitrogen-Doped Carbon with Embedded Co Nanoparticles for High-Performance Rechargeable Zn–Air Batteries with a High Open-Circuit Voltage

Molten-Salt-Assisted Fabrication of Defect-Rich 2D/3D Nitrogen-Doped Carbon with Embedded Co Nanoparticles for High-Performance Rechargeable Zn–Air Batteries with a High Open-Circuit Voltage

Rigid Ligand Confined Synthesis of Carbon Supported Dimeric Fe Sites with High-performance Oxygen Reduction Reaction Activity for Quasi-solid-state Rechargeable Zn-air Batteries.

Dimeric metal sites (DiMSs) in carbon-based single atom catalysts (SACs) offer distinct advantages in optimizing the adsorption energies of the catalytic intermediates and reaction pathways over single atom sites, and thus inspires the investigations on the rational design of DiMSs-based SACs and the accurate discernment of catalytic mechanisms. Here, dimeric Fe sites on carbon blacks (DiFe-N/CBs) are prepared using the precursor of metal-organic complex with a controlled structure, and the rigid ligand confinement secures the preservation of dimeric Fe sites during the thermal treatment. DiFe-N/CBs shows excellent electrocatalytic performance for oxygen reduction reaction (ORR) with a positive half-wave potential of 0.917 V, and excellent durability with negligible activity decay. Theoretical studies reveal that the dimeric Fe sites have an optimal adsorption of OOH* with the Yeager-type binding, illustrating the advantages of DiMSs over SAs in catalyzing ORR. The rechargeable aqueous and quasi-solid-state Zn-air battery assembled using DiFe-N/CBs-based air cathodes achieve small voltage gaps after long term charge/discharge test, showing great promises for practical applications. This synthetic strategy serves a novel platform to produce a scope of catalysts incorporating multimeric metal sites, and studies on the catalytic mechanism lay the foundation for establishing cooperative effect for multidentate adsorption reactions.

Electronic modulation induced by coupling RuO2 with electron-donating Co3O4 for high-active and long-life rechargeable Zn-air batteries

Electronic-state modulation strategy offers great potential in designing RuO2-based bifunctional-electrocatalysts for rechargeable Zn-air batteries (ZABs). Various three-dimensional (3D) transition metal oxides are attempted to couple with RuO2 for constructing an appropriate Ru–O–M interface. This work aims to construct Co3O4-RuO2 heterostructures on carbon sheets (Co3O4/RuO2/NCNS) for boosting electronic transfer and regulation. Experiments and theoretical calculations identify the electronic transfer from Co3O4 to RuO2 that modulates the electronic structure of metal surfaces/interfaces. Specifically, it leads to the increase in Co3+ content, electron-rich state at RuO2 surface and electronic accumulation at interfaces. Moreover, this electronic-state modulation optimizes the d-band center in Co3O4/RuO2 that lowers the reaction barriers and endows interfaces as the biggest contributor to oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performance. The Co3O4/RuO2/NCNS shows a quite low potential difference of 0.62 V and remarkable durability for ORR/OER. Co3O4/RuO2/NCNS-assembled ZABs exhibit an excellent specific capacity of 818.3 mA h g−1 and a superior lifespan over 750 h.

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.

Co-Co6Mo6C2 heterostructure grown on carbon nanofibers as tri-functional electrocatalyst for overall water splitting and rechargeable Zn-air batteries

The advancement of cost-effective and efficient electrocatalysts for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) is crucial for the progress of clean energy conversion and storage technologies. In this work, cobalt (Co) and cobalt-molybdenum (Mo) bimetallic carbide (Co6Mo6C2) heterostructure grown on carbon nanofibers (denoted as Co-Co6Mo6C2/CNFs) as tri-functional electrocatalyst were prepared by a four-step method. Benefiting from the electronic structure modulation between the heterostructure to improve the catalytic activity, Co-Co6Mo6C2/CNFs exhibits high catalytic activity for HER (91 mV @ 10 mA cm−2), OER (293 mV @ 10 mA cm−2) and ORR (E1/2=0.80 V). Moreover, Co-Co6Mo6C2/CNFs assembled overall water splitting electrolyzer achieves a current density of 10 mA cm−2 with a battery voltage of only 1.70 V and has long-term durability. Zn-air batteries (ZABs) based on Co-Co6Mo6C2/CNFs has a power density of 156.6 mW cm−2 with good stability. This study contributes to the development of inexpensive and efficient transition metal-based multifunctional electrocatalysts.

Modulation of electron transfer behavior on Fe2P-Co2P/NPC oxygen electrocatalyst by lattice cation substitution engineering and charge transport network design for rechargeable Zn-air batteries

Crystal structure modulation engineering on the lattice scale and charge transport network design on the micro/nano scale work together to endow oxygen electrocatalysts with high reactivity to fully release the capacity of Zn-air batteries (ZABs) as the next-generation green energy storage devices. Metal phosphide-based oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) electrocatalysts with tunable electronic structures, variable valence states, and moderate overpotentials are recognized as the most promising and ideal candidates for air cathodes. The cation substitution strategy overcomes the drawback that single metal phosphides with fewer active sites and high adsorption barriers are not sufficient to achieve satisfactory electrocatalytic performance. In this paper, the Fe2P-Co2P/NPC oxygen electrocatalyst employing lattice cation site substitution engineering and three-dimensional (3D) conductive network encapsulation strategies are constructed to successfully ensure fast electron transfer behavior and safe charge/discharge energy storage. Noteworthy, the presence of Schottky barriers at the interface of the two materials hinders the electron reflux, which promotes a unidirectional flow of electrons, and increases the electron condensation in the OER and ORR processes. Relying on these features, the Fe2P-Co2P/NPC-assembled liquid ZABs achieved power densities, specific capacities, and energy densities of 175.18 mW cm-2, 805.75 mAh gZn-1, and 958.84 Wh kg-1, respectively, and importantly good rate performances and stability were exhibited even under high-current-density operation. The corresponding flexible solid-state ZABs also possesses superior electrochemical activity and mechanical flexibility. This work paves the way for the construction of bifunctional oxygen electrocatalysts with high-speed electron transfer channels, thus advancing the development of wearable electronic devices.

Engineering Three-Dimensional Interconnected Pores with Plentiful Edge Sites via a Confined Space for Enhanced Oxygen Reduction.

N-Doped carbon sheets based on edge engineering provide more opportunities for improving oxygen reduction reaction (ORR) active sites. However, with regard to the correlation between porous structural configurations and performances, it remains underexplored. Herein, a silica-assisted localized etching method was employed to create two-dimensional mesoporous carbon materials with customizable pore structures, abundant edge sites, and nitrogen functionalities. The mesoporous carbon exhibited superior electrocatalytic performance for the ORR compared to that of a 20 wt % Pt/C catalyst, achieving a half-wave potential of 0.88 V versus RHE, situating them in the leading level of the reported carbon electrocatalysts. Experimental data suggest that the edge graphitic nitrogen sites played a crucial role in the ORR process. The three-dimensional interconnected pores provided a high density of active sites for the ORR and facilitated the efficient transport of electrons. These unique properties make the carbon sheets a promising candidate for highly efficient air cathodes in rechargeable Zn-air batteries.

PtCo nanoalloy embedded nitrogen-doped carbon nanotube for rechargeable Zn-air batteries

The large-scale application of metal-air batteries strongly depends on the development of cost-effective, highly efficient, and durable bifunctional oxygen catalysts. In this work, a facile approach for preparing the monodisperse PtCo nanoalloy anchored the nitrogen-doped carbon nanotubes (PtCo/NCNT) for zinc-air batteries is reported. The nitrogen-doped carbon shell prevents PtCo nanoalloy from exfoliation, dissolution, and aggregation and enables the accessibility of electrolytes to the alloy surface and the electron transfer. Besides, the strong interaction between PtCo nanoalloy and nitrogen-doped carbon can efficiently modulate the electronic structure of the formed active sites. When used as a cathode catalyst, the constructed rechargeable zinc-air battery presents higher power density (268 mW cm−2), specific capacity (840 mAh g−1), and excellent stability. More importantly, the PtCo/NCNT catalyst allows the all-solid-state cell to exhibit remarkable flexibility and high round-trip efficiency at various bending states, demonstrating a potential possibility to replace the conventional Pt/C and RuO2 catalysts.

Boosting ORR/OER bifunctional electrocatalysis by promoting electronic redistribution of Fe-N-C on CoFe-FeNC for ultra-long rechargeable Zn-air batteries

Fe-N-C materials are among the most promising platinum group metals-free catalysts for air cathode of Zn-air batteries (ZABs). However, they are still limited by sluggish reaction kinetics. Herein, we synthesize a novel and effective mesoporous carbon embedded with CoFe nanoclusters, coated with graphitic carbon layers (denoted as CoFe-FeNC). CoFe-FeNC is derived from the pyrolysis of metal-organic complex precursors with grafted iron porphyrin. The CoFe-FeNC catalyst exhibits a half-wave potential (E1/2) of 0.876 V for the oxygen reduction reaction (ORR) and a potential of 1.526 V at 10 mA cm−2 (Ej=10) for the oxygen evolution reaction (OER) in alkaline solutions. Theoretical calculations reveal that the presence of CoFe clusters regulates the electronic structure, optimizing adsorption and desorption during the catalytic reaction. Moreover, flow-ZABs utilizing CoFe-FeNC as the cathode material demonstrate a high specific capacity of 767.5 mAh gZn−1 and an ultra-long lifespan exceeding 1200 h. Additionally, flexible quasi-solid-state rechargeable ZABs incorporating CoFe-FeNC electrocatalysts as the cathode demonstrate well cycling and mechanical flexibility.

Hierarchical Porous Carbon Supported Co2P2O7 Nanoparticles for Oxygen Evolution and Oxygen Reduction in a Rechargeable Zn-Air Battery.

The oxygen reduction/evolution reaction (ORR/OER) represents a pivotal process in metal-air batteries; however, it is constrained by the limitations of slow kinetics. Nevertheless, the creation of long-lasting and bifunctional catalysts represents a significant challenge. This study presents a series of hierarchical porous carbon-supported cobalt pyrophosphate (Co2P2O7-N/C-T) catalysts, prepared through the pyrolysis of porphyrin-based NTU-70 nanosheets with red phosphorus at varying temperatures. The Co2P2O7-N/C-800 not only demonstrates remarkable OER performance with an overpotential of only 290 mV at a current density of 10 mA cm-2 in 1 M KOH, but also exhibits an excellent ΔE of 0.74 V in 0.1 M KOH, which is lower than that of Pt/C + RuO2 (0.76 V). The utilization of Co2P2O7-N/C-800 as an air cathode in a rechargeable Zn-air battery (ZAB) results in a stable discharge voltage plateau of 1.405 V and a high gravimetric energy density of 801.2 mA h gZn-1. This work presents a promising strategy for the design of efficient bifunctional catalysts and demonstrates the critical importance of the interplay between the active center and the supported hierarchical porous carbon.

Electronic coupling effect of multi-metallic heterostructure to enhance oxygen evolution reaction for quasi-solid-state Zn-air batteries

It remains an urgent task to design electrocatalysts with fast oxygen evolution reaction (OER) kinetics and enriched active sites for flexible Zn-air batteries. In this paper, a structure engineering strategy is proposed to design an electrocatalyst with a heterostructure comprising Co@NC and NiMo-LDH on carbon cloth, which serves as an air electrode for a quasi-solid-state Zn-air battery. This unique heterostructure significantly enhances electrocatalytic activity, producing low OER overpotentials of 198 mV at 10 mA cm-2. Moreover, the assembled rechargeable Zn-air battery exhibits a high peak density and long cycle stability. Density functional theory calculations indicate that the multimetallic heterostructure induced synergistic and electronic coupling effects among the metal active sites, facilitating rapid ion and electron transport during the OER process. In addition, the migration of oxygen species at the Ni and Mo sites reduces the reaction potential barrier, resulting in a low OER overpotential of 160 mV.

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.

Carbonized wood fiber-supported S, N-codoped carbon layer-coated multinary metal sulfide nanoarchitecture for efficient oxygen evolution reaction at ampere-level current density

Multinary metal sulfides (MMSs) are highly suitable candidates for the application of electrocatalysis as they offer numerous parameters for optimizing the electronic structure and catalytic sites. Herein, a stable nanoarchitecture consisting of MMSs ((NiCoCrMnFe)Sx) nanoparticles embedded in S, N-codoped carbon (SNC) layers derived from metal organic framework (MOF) and supported on carbonized wood fibers (CWF) was fabricated by directly carbonization. Benefiting from this carbon-coated configuration, along with the synergistic effects within multinary metal systems, (NiCoCrMnFe)Sx@SNC/CWF delivers an exceptionally low overpotential of 260 mV at a high current density of 1000 mA cm−2, a small Tafel slope of 48.5 mV dec−1, and robust electrocatalytic stability. Furthermore, the (NiCoCrMnFe)Sx@SNC/CWF used as the cathode of rechargeable Zn-air batteries demonstrates higher power density and remarkable durability, surpassing that of commercial RuO2. Thus, we showcase the feasibility and advantages of employing highly efficient and durable MMSs materials for low-cost and sustainable energy conversion.