CO2 Nanoenrichment and Nanoconfinement in Cage of Imine Covalent Organic Frameworks for High‐Performance CO2 Cathodes in Li‐CO2 Batteries

The Li‐CO₂ battery is an emerging green energy technology coupling CO₂ capture and conversion. The main drawback of present Li‐CO₂ batteries is serious polarization and poor cycling caused by random deposition of lithium ions and big insulated Li₂CO₃ formation on the cathode during discharge. Herein, covalent organic frameworks (COF) are identified as the porous catalyst in the cathode of Li‐CO₂ batteries for the first time. Graphene@COF is fabricated, graphene with thin and uniform imine COF loading, to enrich and confine CO₂ in the nanospaces of micropores. The discharge voltage is raised by higher local CO₂ concentration, which is predicted by the Nernst equation and realized by CO₂ nanoenrichment. Moreover, uniform lithium ion deposition directed by the graphene@COF nanoconfined CO₂ can produce smaller Li₂CO₃ particles, leading to easier Li₂CO₃ decomposition and thus lower charge voltage. The graphene@COF cathode with 47.5% carbon content achieves a discharge capacity of 27833 mAh g^?1 at 75 mA g^?1, while retaining a low charge potential of 3.5 V at 0.5 A g^?1 for 56 cycles.     

Self‐Assembled 3D Foam‐Like NiCo2O4 as Efficient Catalyst for Lithium Oxygen Batteries

A self‐assembled 3D foam‐like NiCo₂O₄ catalyst has been synthesized via a simple and environmental friendly approach, wherein starch acts as the template to form the unique 3D architecture. Interestingly, when employed as a cathode for lithium oxygen batteries, it demonstrates superior bifunctional electrocatalytic activities toward both the oxygen reduction reaction and the oxygen evolution reaction, with a relatively high round‐trip efficiency of 70% and high discharge capacity of 10 137 mAh g^?1 at a current density of 200 mA g^?1, which is much higher than those in previously reported results. Meanwhile, rotating disk electrode measurements in both aqueous and nonaqueous electrolyte are also employed to confirm the electrocatalytic activity for the first time. This excellent performance is attributed to the synergistic benefits of the unique 3D foam‐like structure and the intrinsically high catalytic activity of NiCo₂O₄.     

Defect Engineering of Chalcogen‐Tailored Oxygen Electrocatalysts for Rechargeable Quasi‐Solid‐State Zinc–Air Batteries

A critical bottleneck limiting the performance of rechargeable zinc–air batteries lies in the inefficient bifunctional electrocatalysts for the oxygen reduction and evolution reactions at the air electrodes. Hybridizing transition‐metal oxides with functional graphene materials has shown great advantages due to their catalytic synergism. However, both the mediocre catalytic activity of metal oxides and the restricted 2D mass/charge transfer of graphene render these hybrid catalysts inefficient. Here, an effective strategy combining anion substitution, defect engineering, and the dopant effect to address the above two critical issues is shown. This strategy is demonstrated on a hybrid catalyst consisting of sulfur‐deficient cobalt oxysulfide single crystals and nitrogen‐doped graphene nanomeshes (CoO_0.87S_0.13/GN). The defect chemistries of both oxygen‐vacancy‐rich, nonstoichiometric cobalt oxysulfides and edge‐nitrogen‐rich graphene nanomeshes lead to a remarkable improvement in electrocatalytic performance, where CoO_0.87S_0.13/GN exhibits strongly comparable catalytic activity to and much better stability than the best‐known benchmark noble‐metal catalysts. In application to quasi‐solid‐state zinc–air batteries, CoO_0.87S_0.13/GN as a freestanding catalyst assembly benefits from both structural integrity and enhanced charge transfer to achieve efficient and very stable cycling operation over 300 cycles with a low discharge–charge voltage gap of 0.77 V at 20 mA cm^?2 under ambient conditions.     

Transition‐Metal‐Doped RuIr Bifunctional Nanocrystals for Overall Water Splitting in Acidic Environments

The establishment of electrocatalysts with bifunctionality for efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acidic environments is necessary for the development of proton exchange membrane (PEM) water electrolyzers for the production of clean hydrogen fuel. RuIr alloy is considered to be a promising electrocatalyst because of its favorable OER performance and potential for HER. Here, the design of a bifunctional electrocatalyst with greatly boosted water‐splitting performance from doping RuIr alloy nanocrystals with transition metals that modify electronic structure and binding strength of reaction intermediates is reported. Significantly, Co‐RuIr results in small overpotentials of 235 mV for OER and 14 mV for HER (@ 10 mA cm^?2 current density) in 0.1 m HClO₄ media. Therefore a cell voltage of just 1.52 V is needed for overall water splitting to produce hydrogen and oxygen. More importantly, for a series of M‐RuIr (M = Co, Ni, Fe), the catalytic activity dependence at fundamental level on the chemical/valence states is used to establish a novel composition‐activity relationship. This permits new design principles for bifunctional electrocatalysts.     

Room‐Temperature Liquid Metal Confined in MXene Paper as a Flexible,Freestanding, and Binder‐Free Anode for Next‐Generation Lithium‐Ion Batteries

Exploring flexible lithium‐ion batteries is required with the ever‐increasing demand for wearable and portable electronic devices. Selecting a flexible conductive substrate accompanying with closely coupled active materials is the key point. Here, a lightweight, flexible, and freestanding MXene/liquid metal paper is fabricated by confining 3 °C GaInSnZn liquid metal in the matrix of MXene paper without any binder or conductive additive. When used as anode for lithium‐ion cells, it can deliver a high discharge capacity of 638.79 mAh g^?1 at 20 mA g^?1. It also exhibits satisfactory rate capacities, with discharge capacities of 507.42, 483.33, 480.22, 452.30, and 404.47 mAh g^?1 at 50, 100, 200, 500, and 1000 mA g^?1, respectively. The cycling performance is obviously improved by slightly reducing the charge–discharge voltage range. The composite paper also has better electrochemical performance than liquid metal coated Cu foil. This study proposes a novel flexible anode by a clever combination of MXene paper and low‐melting point liquid metal, paving the way for next‐generation lithium‐ion batteries.     

Co Nanoparticles Confined in 3D Nitrogen‐Doped Porous Carbon Foams as Bifunctional Electrocatalysts for Long‐Life Rechargeable Zn–Air Batteries

Proper design and simple preparation of nonnoble bifunctional electrocatalysts with high cost performance and strong durability for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is highly demanded but still full of enormous challenges. In this work, a spontaneous gas‐foaming strategy is presented to synthesize cobalt nanoparticles confined in 3D nitrogen‐doped porous carbon foams (CoNCF) by simply carbonizing the mixture of citric acid, NH₄Cl, and Co(NO₃)₂·6H₂O. Thanks to its particular 3D porous foam architecture, ultrahigh specific surface area (1641 m² g^?1), and homogeneous distribution of active sites (C–N, Co–N_x, and Co–O moieties), the optimized CoNCF‐1000‐80 (carbonized at 1000 °C, containing 80 mg Co(NO₃)₂·6H₂O in precursors) catalyst exhibits a remarkable bifunctional activity and long‐term durability toward both ORR and OER. Its bifunctional activity parameter (ΔE) is as low as 0.84 V, which is much smaller than that of noble metal catalyst and comparable to state‐of‐the‐art bifunctional catalysts. When worked as an air electrode catalyst in rechargeable Zn–air batteries, a high energy density (797 Wh kg^?1), a low charge/discharge voltage gap (0.75 V), and a long‐term cycle stability (over 166 h) are achieved at 10 mA cm^?2.     

Boosting Bifunctional Oxygen Electrocatalysis with 3D Graphene Aerogel‐Supported Ni/MnO Particles

Electrocatalysts for oxygen‐reduction and oxygen‐evolution reactions (ORR and OER) are crucial for metal–air batteries, where more costly Pt‐ and Ir/Ru‐based materials are the benchmark catalysts for ORR and OER, respectively. Herein, for the first time Ni is combined with MnO species, and a 3D porous graphene aerogel‐supported Ni/MnO (Ni–MnO/rGO aerogel) bifunctional catalyst is prepared via a facile and scalable hydrogel route. The synthetic strategy depends on the formation of a graphene oxide (GO) crosslinked poly(vinyl alcohol) hydrogel that allows for the efficient capture of highly active Ni/MnO particles after pyrolysis. Remarkably, the resulting Ni–MnO/rGO aerogels exhibit superior bifunctional catalytic performance for both ORR and OER in an alkaline electrolyte, which can compete with the previously reported bifunctional electrocatalysts. The MnO mainly contributes to the high activity for the ORR, while metallic Ni is responsible for the excellent OER activity. Moreover, such bifunctional catalyst can endow the homemade Zn–air battery with better power density, specific capacity, and cycling stability than mixed Pt/C + RuO₂ catalysts, demonstrating its potential feasibility in practical application of rechargeable metal–air batteries.     

Oxygen Vacancy–Rich In‐Doped CoO/CoP Heterostructure as an Effective Air Cathode for Rechargeable Zn–Air Batteries

An efficient and low‐cost electrocatalyst for reversible oxygen electrocatalysis is crucial for improving the performance of rechargeable metal?air batteries. Herein, a novel oxygen vacancy–rich 2D porous In‐doped CoO/CoP heterostructure (In‐CoO/CoP FNS) is designed and developed by a facile free radicals–induced strategy as an effective bifunctional electrocatalyst for rechargeable Zn–air batteries. The electron spin resonance and X‐ray absorption near edge spectroscopy provide clear evidence that abundant oxygen vacancies are formed in the interface of In‐CoO/CoP FNS. Owing to abundant oxygen vacancies, porous heterostructure, and multiple components, In‐CoO/CoP FNS exhibits excellent oxygen reduction reaction activity with a positive half‐wave potential of 0.81 V and superior oxygen evolution reaction activity with a low overpotential of 365 mV at 10 mA cm^?2. Moreover, a home‐made Zn–air battery with In‐CoO/CoP FNS as an air cathode delivers a large power density of 139.4 mW cm^?2, a high energy density of 938 Wh kg_Zn^?1, and can be steadily cycled over 130 h at 10 mA cm^?2, demonstrating great application potential in rechargeable metal–air batteries.     

Metal–Organic‐Framework‐Derived Hybrid Carbon Nanocages as a Bifunctional Electrocatalyst for Oxygen Reduction and Evolution

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are cornerstone reactions for many renewable energy technologies. Developing cheap yet durable substitutes of precious‐metal catalysts, especially the bifunctional electrocatalysts with high activity for both ORR and OER reactions and their streamlined coupling process, are highly desirable to reduce the processing cost and complexity of renewable energy systems. Here, a facile strategy is reported for synthesizing double‐shelled hybrid nanocages with outer shells of Co‐N‐doped graphitic carbon (Co‐NGC) and inner shells of N‐doped microporous carbon (NC) by templating against core–shell metal–organic frameworks. The double‐shelled NC@Co‐NGC nanocages well integrate the high activity of Co‐NGC shells into the robust NC hollow framework with enhanced diffusion kinetics, exhibiting superior electrocatalytic properties to Pt and RuO₂ as a bifunctional electrocatalyst for ORR and OER, and hold a promise as efficient air electrode catalysts in Zn–air batteries. First‐principles calculations reveal that the high catalytic activities of Co‐NGC shells are due to the synergistic electron transfer and redistribution between the Co nanoparticles, the graphitic carbon, and the doped N species. Strong yet favorable adsorption of an OOH* intermediate on the high density of uncoordinated hollow‐site C atoms with respect to the Co lattice in the Co‐NGC structure is a vital rate‐determining step to achieve excellent bifunctional electrocatalytic activity.     

ZIF‐8/ZIF‐67‐Derived Co‐Nx‐Embedded 1D Porous Carbon Nanofibers with Graphitic Carbon‐Encased Co Nanoparticles as an Efficient Bifunctional Electrocatalyst

Herein, an approach is reported for fabrication of Co‐N_x‐embedded 1D porous carbon nanofibers (CNFs) with graphitic carbon‐encased Co nanoparticles originated from metal–organic frameworks (MOFs), which is further explored as a bifunctional electrocatalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Electrochemical results reveal that the electrocatalyst prepared by pyrolysis at 1000 °C (CoNC‐CNF‐1000) exhibits excellent catalytic activity toward ORR that favors the four‐electron ORR process and outstanding long‐term stability with 86% current retention after 40 000 s. Meanwhile, it also shows superior electrocatalytic activity toward OER, reaching a lower potential of 1.68 V at 10 mA cm^?2 and a potential gap of 0.88 V between the OER potential (at 10 mA cm^?2) and the ORR half‐wave potential. The ORR and OER performance of CoNC‐CNF‐1000 have outperformed commercial Pt/C and most nonprecious‐metal catalysts reported to date. The remarkable ORR and OER catalytic performance can be mainly attributable to the unique 1D structure, such as higher graphitization degree beneficial for electronic mobility, hierarchical porosity facilitating the mass transport, and highly dispersed CoN_xC active sites functionalized carbon framework. This strategy will shed light on the development of other MOF‐based carbon nanofibers for energy storage and electrochemical devices.     

A High‐Capacity O2‐Type Li‐Rich Cathode Material with a Single‐Layer Li2MnO3 Superstructure

A high capacity cathode is the key to the realization of high‐energy‐density lithium‐ion batteries. The anionic oxygen redox induced by activation of the Li₂MnO₃ domain has previously afforded an O3‐type layered Li‐rich material used as the cathode for lithium‐ion batteries with a notably high capacity of 250–300 mAh g^?1. However, its practical application in lithium‐ion batteries has been limited due to electrodes made from this material suffering severe voltage fading and capacity decay during cycling. Here, it is shown that an O2‐type Li‐rich material with a single‐layer Li₂MnO₃ superstructure can deliver an extraordinary reversible capacity of 400 mAh g^?1 (energy density: ≈1360 Wh kg^?1). The activation of a single‐layer Li₂MnO₃ enables stable anionic oxygen redox reactions and leads to a highly reversible charge–discharge cycle. Understanding the high performance will further the development of high‐capacity cathode materials that utilize anionic oxygen redox processes.     

Efficient Bifunctional Catalytic Electrodes with Uniformly Distributed NiN2 Active Sites and Channels for Long‐Lasting Rechargeable Zinc–Air Batteries

Freestanding bifunctional electrodes with outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) properties are of great significance for zinc–air batteries, attributed to the avoided use of organic binder and strong adhesion with substrates. Herein, a strategy is developed to fabricate freestanding bifunctional electrodes from the predeposited nickel nanoparticles (Ni‐NCNT) on carbon fiber paper. The steric effect of monodispersed SiO₂ nanospheres limits the configuration of carbon atoms forming 3D interconnected nanotubes with uniformly distributed NiN₂ active sites. The bifunctional electrodes (Ni‐NCNT) demonstrate ideal ORR and OER properties. The zinc–air batteries assembled with Ni‐NCNT directly exhibit extremely outstanding long term stability (2250 cycles with 10 mA cm^?2 charge/discharge current density) along with high power density of 120 mV cm^?2 and specific capacity of 834.1 mA h g^?1. This work provides a new view to optimize the distribution of active sites and the electrode structure.     

Nanosilica‐Confined Synthesis of Orthogonally Active Catalytic Metal Nanocrystals in the Compartmentalized Carbon Framework

Multifunctionalized porous catalytic nanoarchitectures are highly desirable for a variety of chemical transformations; however, selective installation of different catalysts with spatial and functional precision working synergistically and predictably, is highly challenging. Here, a synthetic strategy is developed toward the customizable combination of orthogonally reactive metal nanocrystals within interconnected carbon‐cavities as a compartmentalized framework by employing aminated‐silica‐directed thermal solid‐state nanoconfined synthesis of metal nanocrystals and endotemplating concomitant carbonization‐mediated interlocking, as key processes. The main advantage of the strategy is the facility to choose any combination of metals, which can be further employed according to the desired application. The strategically synthesized compartmentalized multifunctional catalytic architectures of Pd‐Pt@Com‐CF regulate the O₂‐mediated selective cascade oxidation reaction converting alcohol to acid with high yield and selectivity; and another Pt‐Ir@Com‐CF platform is demonstrated as a bifunctional electrocatalyst for oxygen reduction/evolution reactions.     

Dendrite‐Free Lithium Deposition via Flexible‐Rigid Coupling Composite Network for LiNi0.5Mn1.5O4/Li Metal Batteries

Notorious lithium dendrite causes severe capacity fade and harsh safety issues of lithium metal batteries, which hinder the practical applications of lithium metal electrodes in higher energy rechargeable batteries. Here, a kind of 3D‐cross‐linked composite network is successfully employed as a flexible‐rigid coupling protective layer on a lithium metal electrode. During the plating/stripping process, the composite protective layer would enable uniform distribution of lithium ions in the adjacent regions of the lithium electrode, resulting in a dendrite‐free deposition at a current density of 2 mA cm^?2. The LiNi_0.5Mn_1.5O₄‐based lithium metal battery presents an excellent cycling stability at a voltage range of 3.5–5.0 V with the induction of 3D‐cross‐linked composite protective layer. From an industrial field application of view, thin lithium metal electrodes (40 µm, with 4 times excess lithium) can be used in LiNi_0.5Mn_1.5O₄ (with industrially significant loading of 18 mg cm^?2 and 2.6 mAh cm^?2)‐based lithium metal batteries, which reveals a promising opportunity for practical applicability in high energy lithium metal batteries.     

Facile Synthesis of Ultrasmall CoS2 Nanoparticles within Thin N‐Doped Porous Carbon Shell for High Performance Lithium‐Ion Batteries

Cobalt sulfide (CoS₂) is considered one of the most promising alternative anode materials for high‐performance lithium‐ion batteries (LIBs) by virtue of its remarkable electrical conductivity, high theoretical capacity, and low cost. However, it suffers from a poor cycling stability and low rate capability because of its volume expansion and dissolution of the polysulfide intermediates in the organic electrolytes during the battery charge/discharge process. In this study, a novel porous carbon/CoS₂ composite is prepared by using nano metal–organic framework (MOF) templates for high‐preformance LIBs. The as‐made ultrasmall CoS₂ (15 nm) nanoparticles in N‐rich carbon exhibit promising lithium storage properties with negligible loss of capacity at high charge/discharge rate. At a current density of 100 mA g^?1, a capacity of 560 mA h g^?1 is maintained after 50 cycles. Even at a current density as high as 2500 mA g^?1, a reversible capacity of 410 mA h g^?1 is obtained. The excellent and highly stable battery performance should be attributed to the synergism of the ultrasmall CoS₂ particles and the thin N‐rich porous carbon shells derieved from nanosized MOF precusors.     

A Cost‐Efficient Bifunctional Ultrathin Nanosheets Array for Electrochemical Overall Water Splitting

The design of cost‐efficient earth‐abundant catalysts with superior performance for the electrochemical water splitting is highly desirable. Herein, a general strategy for fabricating superior bifunctional water splitting electrodes is reported, where cost‐efficient earth‐abundant ultrathin Ni‐based nanosheets arrays are directly grown on nickel foam (NF). The newly created Ni‐based nanosheets@NF exhibit unique features of ultrathin building block, 3D hierarchical structure, and alloy effect with the optimized Ni₅Fe layered double hydroxide@NF (Ni₅Fe LDH@NF) exhibiting low overpotentials of 210 and 133 mV toward both oxygen evolution reaction and hydrogen evolution reaction at 10 mA cm^?2 in alkaline condition, respectively. More significantly, when applying as the bifunctional overall water splitting electrocatalyst, the Ni₅Fe LDH@NF shows an appealing potential of 1.59 V at 10 mA cm^?2 and also superior durability at the very high current density of 50 mA cm^?2.     

Cobalt Iron Hydroxide as a Precious Metal‐Free Bifunctional Electrocatalyst for Efficient Overall Water Splitting

Highly efficient and stable electrocatalysts from inexpensive and earth‐abundant elements are emerging materials in the overall water splitting process. Herein, cobalt iron hydroxide nanosheets are directly deposited on nickel foam by a simple and rapid electrodeposition method. The cobalt iron hydroxide (CoFe/NF) nanosheets not only allow good exposure of the highly active surface area but also facilitate the mass and charge transport capability. As an anode, the CoFe/NF electrocatalyst displays excellent oxygen evolution reaction catalytic activity with an overpotential of 220 mV at a current density of 10 mA cm^?2. As a cathode, it exhibits good performance in the hydrogen evolution reaction with an overpotential of 110 mV, reaching a current density of 10 mA cm^?2. When CoFe/NF electrodes are used as the anode and the cathode for water splitting, a low cell voltage of 1.64 V at 10 mA cm^?2 and excellent stability for 50 h are observed. The present work demonstrates a possible pathway to develop a highly active and durable substitute for noble metal electrocatalysts for overall water splitting.     

Highly active and durable core-corona structured bifunctional catalyst for rechargeable metal-air battery application

A new class of core-corona structured bifunctional catalyst (CCBC) consisting of lanthanum nickelate centers supporting nitrogen-doped carbon nanotubes (NCNT) has been developed for rechargeable metal-air battery application. The nanostructured design of the catalyst allows the core and corona to catalyze the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. These materials displayed exemplary OER and ORR activity through half-cell testing, comparable to state of the art commercial lanthanum nickelate (LaNiO(3)) and carbon-supported platinum (Pt/C), with added bifunctional capabilities allowing metal-air battery rechargeability. LaNiO(3) and Pt/C are currently the most accepted benchmark electrocatalyst materials for the OER and ORR, respectively; thus with comparable activity toward both of these reactions, CCBC are presented as a novel, inexpensive catalyst component for the cathode of rechargeable metal-air batteries. Moreover, after full-range degradation testing (FDT) CCBC retained excellent activity, retaining 3 and 13 times greater ORR and OER current upon comparison to state of the art Pt/C. Zinc-air battery performances of CCBC is in good agreement with the half-cell experiments with this bifunctional electrocatalyst displaying high activity and stability during battery discharge, charge, and cycling processes. Owing to its outstanding performance toward both the OER and ORR, comparable with the highest performing commercial catalysts to date for each of the respective reaction, coupled with high stability and rechargeability, CCBC is presented as a novel class of bifunctional catalyst material that is very applicable to future generation rechargeable metal-air batteries.     

Lithiophilic 3D Nanoporous Nitrogen‐Doped Graphene for Dendrite‐Free and Ultrahigh‐Rate Lithium‐Metal Anodes

The key bottlenecks hindering the practical implementations of lithium‐metal anodes in high‐energy‐density rechargeable batteries are the uncontrolled dendrite growth and infinite volume changes during charging and discharging, which lead to short lifespan and catastrophic safety hazards. In principle, these problems can be mitigated or even solved by loading lithium into a high‐surface‐area, conductive, and lithiophilic porous scaffold. However, a suitable material that can synchronously host a large loading amount of lithium and endure a large current density has not been achieved. Here, a lithiophilic 3D nanoporous nitrogen‐doped graphene as the sought‐after scaffold material for lithium anodes is reported. The high surface area, large porosity, and high conductivity of the nanoporous graphene concede not only dendrite‐free stripping/plating but also abundant open space accommodating volume fluctuations of lithium. This ingenious scaffold endows the lithium composite anode with a long‐term cycling stability and ultrahigh rate capability, significantly improving the charge storage performance of high‐energy‐density rechargeable lithium batteries.     

Novel MOF‐Derived Co@N‐C Bifunctional Catalysts for Highly Efficient Zn–Air Batteries and Water Splitting

Metal–organic frameworks (MOFs) and MOF‐derived materials have recently attracted considerable interest as alternatives to noble‐metal electrocatalysts. Herein, the rational design and synthesis of a new class of Co@N‐C materials (C‐MOF‐C2‐T) from a pair of enantiotopic chiral 3D MOFs by pyrolysis at temperature T is reported. The newly developed C‐MOF‐C2‐900 with a unique 3D hierarchical rodlike structure, consisting of homogeneously distributed cobalt nanoparticles encapsulated by partially graphitized N‐doped carbon rings along the rod length, exhibits higher electrocatalytic activities for oxygen reduction and oxygen evolution reactions (ORR and OER) than that of commercial Pt/C and RuO₂, respectively. Primary Zn–air batteries based on C‐MOF‐900 for the oxygen reduction reaction (ORR) operated at a discharge potential of 1.30 V with a specific capacity of 741 mA h g_Zn^–1 under 10 mA cm^–2. Rechargeable Zn–air batteries based on C‐MOF‐C2‐900 as an ORR and OER bifunctional catalyst exhibit initial charge and discharge potentials at 1.81 and 1.28 V (2 mA cm^–2), along with an excellent cycling stability with no increase in polarization even after 120 h – outperform their counterparts based on noble‐metal‐based air electrodes. The resultant rechargeable Zn–air batteries are used to efficiently power electrochemical water‐splitting systems, demonstrating promising potential as integrated green energy systems for practical applications.