Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （...Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） play a critical role in the operation of rechargeable zinc-air batteries. Herein, we report a simple and scalable strategy to fabricate porous carbon polyhedra using Zn-doped Co-based zeolitic imidazolate frameworks （ZnCo-ZIFs） as precursors. Strikingly, Zn doping leads to smaller Co nanoparticles and higher nitrogen content, which in turn enhances the ORR and OER activities of the obtained porous carbon polyhedra. The synergistic effect of the N-doped carbon and cobalt nanoparticles in the composite, the improved conductivity resulting from the high graphitization of carbon, and the large surface area of the porous polyhedral structure resulted in porous carbon polyhedra with excellent ORR and OER electrocatalytic activity in alkaline media. More importantly, air cathodes based on the optimal porous carbon polyhedra further exhibited superior performance to Pt/C catalysts in primary and rechargeable zinc-air batteries.展开更多
Metal-organic frameworks(MOFs)and MOF-derived materials have attracted great attention as alternatives to noble-metal based electrocatalysts owing to their intriguing structure properties,especially for high efficienc...Metal-organic frameworks(MOFs)and MOF-derived materials have attracted great attention as alternatives to noble-metal based electrocatalysts owing to their intriguing structure properties,especially for high efficiency and stable oxygen reduction reaction(ORR).Herein,we employed a one-pot reaction to make a multimetal(Fe,Co,Cu,and Zn)mixed zeolitic imidazolate framework(MM-ZIF)via adopting a simple in situ redox reaction.Further pyrolysis of the target MM-ZIF,a highly porous carbon polyhedron(FC-C@NC)grafted with abundant carbon nanotubes was obtained,in which ultrasmall Co nanoparticles with partial lattice sites substituted by Fe and Cu were embedded.The obtained FC-C@NC possessed large surface area,highly porous structure,widely-spread metal active sites,and conductive carbon frameworks,contributing to outstanding ORR activity and long-term stability.It displayed superior tolerance to methanol crossover and exceeded the commercial Pt/C catalyst and most previously reported non-noble-metal catalysts.Impressively,the as-produced FC-C@NC-based zinc-air battery afforded an open-circuit potential of 1.466 V,a large specific capacity of 659.5 mAh/g,and a high gravimetric energy density of 784.3 Wh/kgZn,significantly outperforming the Pt/C-based cathode.展开更多
An atomically dispersed FeCo-NC material with the 3D flower-like morphology was used as a unique substrate for the controllable deposition of ultrasmall NiFe layered double hydroxide nanodots(termed as NiFe-NDs)to sim...An atomically dispersed FeCo-NC material with the 3D flower-like morphology was used as a unique substrate for the controllable deposition of ultrasmall NiFe layered double hydroxide nanodots(termed as NiFe-NDs)to simultaneously promote the sluggish kinetics of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).The size-limiting growth of NiFe-NDs(~4.0 nm in diameter)was realized via the confinement of the 3D flower-like mesoporous structure and the rich N/O functionality of FeCo-NC.Benefiting from the distinctive structure with the simultaneously maximum exposure of both OER and ORR active sites,the NiFe-ND/FeCo-NC composite showed an ORR halfwave potential of 0.85 V and an OER potential of 1.66 V in0.1 mol L-1KOH at 10.0 mA cm-2.In-situ Raman analysis suggested the activity of OER was derived from the Ni sites on NiFe-ND/FeCo-NC.Moreover,the NiFe-ND/FeCo-NC-assembled Zn-air battery(ZAB)exhibited a very small discharge-charge voltage gap of 0.87 V at 20 mA cm-2and robust cycling stability.Furthermore,the NiFe-ND/FeCo-NC composite was also applicable for fabricating all-solid-state ZAB to power wearable electronics with superior cycling stability under deformation.Our work could enlighten a new applicable branch of atomically dispersed metal-nitrogen-carbon materials as unique substrates for fabricating multifunctional electrocatalysts.展开更多
Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution ...Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution reactions(OER).Herein,we fabricate a range of bifunctional M-N-C(metal-nitrogen-carbon)catalysts containing M-Nx coordination sites and M/MxC nanoparticles(M=Co,Fe,and Cu)using a new class ofγ-cyclodextrin(CD)based metal-organic framework as the precursor.With the two types of active sites interacting with each other in the catalysts,the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave(E1/2)potential(~0.917 and 0.906 V,respectively),which are higher than Cu@C-CuNC(~0.829 V)and the commercial Pt/C(~0.861 V).As a bifunctional electrocatalyst,the Co@C-CoNC exhibits the best performance,showing a bifunctional ORR/OER overpotential(ΔE)of~0.732 V,which is much lower than that of Fe@C-FeNC(~0.831 V)and Cu@C-CuNC(~1.411 V),as well as most of the robust bifunctional electrocatalysts reported to date.Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER,resulting in an enhanced bifunctional electrocatalytic performance.The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm^(−2) at 270.30 mA cm^(−2),higher than the combination of commercial Pt/C+RuO2(~158.90 mW cm^(−2) at 265.80 mA cm^(−2))catalysts.During the galvanostatic discharge at 10 mA cm^(−2),the ZAB delivered an almost stable discharge voltage of 1.2 V for~140 h,signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.展开更多
Carbon materials featuring hierarchical pores and atomically dispersed metal sites are promising catalysts for energy storage and conversion applications.Herein,we developed a facile strategy to construct functional c...Carbon materials featuring hierarchical pores and atomically dispersed metal sites are promising catalysts for energy storage and conversion applications.Herein,we developed a facile strategy to construct functional carbon materials with a fluffy peony-like structure and dense binary FeCo-Nx active sites(termed as f-FeCo-CNT).By regulating the metal content in precursors,a three-dimensional(3D)interconnected conductive carbon nanotubes network was in-situ formed throughout the atomically dispersed FeCo-NC matrix during pyrolysis.Taking advantage of rich pore hierarchy and co-existence of highly active FeCo-Nx sites and beneficial FeCo alloy nanoparticles,the f-FeCo-CNT material exhibited excellent bifunctional performance towards oxygen reduction reaction/oxygen evolution reactions(ORR/OER)with respect to the atomically dispersed FeCo-NC(SA-f-FeCo-NC)and commercial Pt/C+Ru02 mixture,surpassing the SA-f-FeCo-NC with a 20 mV higher ORR half-wave potential and a 100 mV lower OER overpotential(at 10.0 mA/cm^2).Remarkably,the f-FeCo-CNT-assembled Zn-air battery(ZAB)possessed a maximum specific power of 195.8 mW/cm^2,excellent rate capability,and very good cycling stability at large current density of 20.0 mA/cm^2.This work provides a facile and feasible synthetic strategy of constructing low-cost cathode materials with excellent comprehensive ZAB performance.展开更多
Rechargeable zinc-air batteries(ZABs)have attracted much attention as the next-generation energy conversion and storage devices due to the abundance and environmental friendliness of zinc(Zn)for anode materials,as wel...Rechargeable zinc-air batteries(ZABs)have attracted much attention as the next-generation energy conversion and storage devices due to the abundance and environmental friendliness of zinc(Zn)for anode materials,as well as the safety and low cost of aqueous electrolytes.However,rational design of nonprecious and low-cost integrated air cathode materials with a desirable bifunctional oxygen electrocatalytic performance remains a great challenge for the commercialization of rechargeable ZABs.In previous research studies,various cost-effective carbon-supported electrocatalysts and light-weight carbon-based current collectors for air cathodes have been developed,showing vast potential in the application of carbon-based materials.To improve the bifunctional performance and integration of air cathodes,efforts with respect to the design of morphology,defects,and synergistic effects of carbon-based materials have been made.In this perspective,the general understanding of the air cathode construction and the battery working mechanism is discussed.The recent progress in the design of carbon-based materials for air cathodes in rechargeable ZABs is summarized.Several possible future research directions and the expected development trends are also discussed,aiming to facilitate the commercialization of advanced rechargeable ZABs in our life.展开更多
Oxygen electrocatalysts are of great importance for the air electrode in zinc-air batteries(ZABs).Owing to the high specific surface area,controllable pore size and unsaturated metal active sites,metal-organic framewo...Oxygen electrocatalysts are of great importance for the air electrode in zinc-air batteries(ZABs).Owing to the high specific surface area,controllable pore size and unsaturated metal active sites,metal-organic frameworks(MOFs)derivatives have been widely studied as oxygen electrocatalysts in ZABs.To date,many strategies have been developed to generate efficient oxygen electrocatalysts from MOFs for improving the performance of ZABs.In this review,the latest progress of the MOF-derived non-noble metal-oxygen electrocatalysts in ZABs is reviewed.The performance of these MOF-derived catalysts toward oxygen reduction,and oxygen evolution reactions is discussed based on the categories of metal-free carbon materials,single-atom catalysts,metal cluster/carbon composites and metal compound/carbon composites.Moreover,we provide a comprehensive overview on the design strategies of various MOF-derived non-noble metal-oxygen electrocatalysts and their structure-performance relationship.Finally,the challenges and perspectives are provided for further advancing the MOF-derived oxygen electrocatalysts in ZABs.展开更多
Developing low-cost, high-performance elec- trocatalysts for the oxygen reduction reaction （ORR） is crucial for implementation of fuel cells and metal-air batteries into practical applications. Graphene-based cataly...Developing low-cost, high-performance elec- trocatalysts for the oxygen reduction reaction （ORR） is crucial for implementation of fuel cells and metal-air batteries into practical applications. Graphene-based catalysts have been extensively investigated for ORR in alkaline electrolytes. However, their performance in acidic electrolytes still requires further improvement compared to the Pt/C catalyst. Here we report a self-templating approach to prepare graphene-based sandwich-like porous carbon nanosheets for efficient ORR in both alkaline and acidic electrolytes. Graphene oxides were first used to adsorb m-phenylenediamine molecules which can form a nitrogen-rich polymer network after oxidative poly- merization. Then iron （Fe） salt was introduced into the polymer network and transformed into ORR active Fe-N-C sites along with Fe, FeS, and FEN0.05 nanopartides after pyr- olysis, generating ORR active sandwich-like carbon na- nosheets. Due to the presence of multiple ORR active sites. The as-obtained catalyst exhibited prominent ORR activity with a half-wave potential -30 mV more positive than Pt/C in 0.1 mol L-1 KOH, while the half-wave potential of the catalyst was only -40 mV lower than that of commercial Pt/C in 0.1 mol L-1 HClO4. The unique planar sandwich-like structure could expose abundant active sites for ORR. Meanwhile, the graphene layer and porous structure could simultaneously enhance electrical conductivity and facilitate mass transport. The prominent electrocatalytic activity and durability in both alkaline and acidic electrolytes indicate that these carbon na- nosheets hold great potential as alternatives to precious metal- based catalysts, as demonstrated in zinc-air batteries and proton exchange membrane fuel cells.展开更多
Zinc-air batteries(ZABs)are widely studied because of their high theoretical energy density,high battery voltage,environmental protection,and low price.However,the slow kinetics of oxygen reduction reaction(ORR)and ox...Zinc-air batteries(ZABs)are widely studied because of their high theoretical energy density,high battery voltage,environmental protection,and low price.However,the slow kinetics of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)on the air electrode limits the further application of ZABs,so that how to develop a cheap,efficient,and stable catalyst with bifunctional catalytic activity is the key to solving the development of ZABs.Transition metal compounds are widely used as cathode materials for ZABs due to their low cost,high electrocatalytic activity,and stable structure.This review summarizes the research progress of transition metal compounds as bifunctional catalysts for ZABs.The development history,operation principle,and mechanism of ORR and OER reactions are introduced first.The application and development of transition metal compounds as bifunctional catalysts for ZABs in recent years are systematically introduced,including transition metal oxides(TMOs),transition metal nitrides(TMNs),transition metal sulfides(TMSs),transition metal carbides(TMCs),transition metal phosphates(TMPs),and others.In addition,the shortcomings of transition metal compounds as bifunctional catalysts for ZABs were summarized and reasonable design strategies and improvement measures were put forward,aiming at providing a reference for the design and construction of high-performance ZABs cathode materials.Finally,the challenges and future in this field are discussed and prospected.展开更多
Robust oxygen reduction reaction(ORR)catalysts are essential for energy storage and conversion devices,but their development remains challenging.Herein,we design a single-atom catalyst featuring isolated Co anchored o...Robust oxygen reduction reaction(ORR)catalysts are essential for energy storage and conversion devices,but their development remains challenging.Herein,we design a single-atom catalyst featuring isolated Co anchored on nitrogen-doped carbon(Co-SAC/NC)via a highly efficient“plasma-bombing”strategy.With a high loading(up to 2.5wt%),the well-dispersed single Co atoms in Co-SAC/NC give it robust ORR performance in an alkaline medium.It also demonstrates excellent battery performance when implemented as the air-cathode catalyst in a zinc-air battery(ZAB).Theoretical calculations reveal that the Co-N_(4)moiety experiences an“extraction/recovery”structural evolution during the ORR process,and the reaction's rate-determining step is the formation of OOH∗(reaction intermediate).This work provides a new strategy for designing robust ORR catalysts for high-performance ZABs and other energy-conversion devices.展开更多
The demanding all-in-one electrocatalyst system for oxygen reduction reaction(ORR), oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) in zinc-air batteries or water splitting requires elaborate mater...The demanding all-in-one electrocatalyst system for oxygen reduction reaction(ORR), oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) in zinc-air batteries or water splitting requires elaborate material manufacturing, which is usually complicated and time-consuming.Efficient interface engineering between MXene and highly active electrocatalytic species(CoS_(2)) is, herein, achieved by an in situ hydrothermal growth and facile sulfurization process.The CoS_(2)@MXene electrocatalyst is composed by one-dimensional CoS_(2) nanowires and two-dimensional MXene nanosheets, which lead to a hierarchical structure(large specific surface area and abundant active sites), a spatial electron redistribution(high intrinsic activity), and high anchoring strength(superior performance stability). Therefore, the electrocatalyst achieves enhanced catalytic activity and longtime stability for ORR(a half-wave potential of 0.80 V), OER(an overpotential of 270 mV at 10 mA cm^(-2), i.e., η10= 270 mV)and HER(η10= 175 mV). Furthermore, the asymmetry water splitting system based on the CoS_(2)@MXene composites delivers a low overall voltage of 1.63 V at 10 mA cm^(-2). The solidstate zinc-air batteries using CoS_(2)@MXene as the air cathode display a small charge-discharge voltage gap(0.53 V at1 mA cm^(-2)) and superior stability(60 circles and 20-h continuous test). The energy interconversion between the chemical energy and electricity can be achieved by a self-powered system via integrating the water splitting system and quasisolid-state zinc-air batteries. Supported by in situ Raman analyses, the formation of cobalt oxyhydroxide species provides the active sites for water oxidation. This study paves apromising avenue for the design and application of multifunctional nanocatalysts.展开更多
Zn-air batteries(ZABs)as a class of promising energy storage setups are generally powered by efficient and robust catalysts at the oxygen-involving cathode.Although the existing non-noble catalysts have outperformed n...Zn-air batteries(ZABs)as a class of promising energy storage setups are generally powered by efficient and robust catalysts at the oxygen-involving cathode.Although the existing non-noble catalysts have outperformed noble Pt benchmark in the alkaline liquid-state ZABs,to the best of our knowledge few have excelled Pt in quasi-solid-state(QSS)ZABs.Herein,we found that an integrated Mn-Co cathode derived from the bimetallic Mn/Co metal organic frameworks generates a 1.4-fold greater power density in the QSS ZABs than a Pt cathode while its power density in liquid-state ZABs is only 0.8-fold of the latter.Moreover,such Mn-Co catalyst delivers high-rate oxygen reduction reaction(ORR)capability with half-wave potential of 0.84 V.The in-depth characterizations and analyses have demonstrated that the Co and Mn species show the specific affinity towards H_(2)O and O_(2),respectively,synergizing the ORR process in the water-deficient environment of QSS ZABs.This work has enlightened the rational design of non-noble metal catalysts to improve the power density of QSS ZABs.展开更多
Smart wearable devices are regarded to be the next prevailing technology product after smartphones and smart homes,and thus there has recently been rapid development in flexible electronic energy storage devices.Among...Smart wearable devices are regarded to be the next prevailing technology product after smartphones and smart homes,and thus there has recently been rapid development in flexible electronic energy storage devices.Among them,flexible solid-state zinc-air batteries have received widespread attention because of their high energy density,good safety,and stability.Efficient bifunctional oxygen electrocatalysts are the primary consideration in the development of flexible solid-state zinc-air batteries,and self-supported air cathodes are strong candidates because of their advantages including simplified fabrication process,reduced interfacial resistance,accelerated electron transfer,and good flexibility.This review outlines the research progress in the design and construction of nanoarray bifunctional oxygen electrocatalysts.Starting from the configuration and basic principles of zinc-air batteries and the strategies for the design of bifunctional oxygen electrocatalysts,a detailed discussion of self-supported air cathodes on carbon and metal substrates and their uses in flexible zinc-air batteries will follow.Finally,the challenges and opportunities in the development of flexible zinc-air batteries will be discussed.展开更多
The rational design of Fe–N–C catalysts that possess easily accessible active sites and favorable mass transfer,which are usually determined by the structure of catalyst supports,is crucial for the oxygen reduction ...The rational design of Fe–N–C catalysts that possess easily accessible active sites and favorable mass transfer,which are usually determined by the structure of catalyst supports,is crucial for the oxygen reduction reaction(ORR).In this study,an oleic acid-assisted soft-templating approach is developed to synthesize size-controlled nitrogen-doped carbon nanoparticles(ranging from 130 nm to 60 nm and 35 nm,respectively)that feature spiral mesopores on their surface(SMCs).Next,atomically dispersed Fe–Nx sites are fabricated on the size-tunable SMCs(Fe1/SMC-x,where x represents the SMC size)and the size-dependent activity toward ORR is investigated.It is found that the catalytic performance of Fe1/SMCs is significantly influenced by the size of SMCs,where the Fe1/SMC-60 catalyst shows the highest ORR activity with a half-wave potential of 0.90 V vs.RHE in KOH electrolyte,indicating that the gas-liquid-solid three-phase interface on the Fe1/SMC-60 enhances the accessibility of Fe–Nx sites.In addition,when using Fe1/SMC-60 as the cathode catalyst in aqueous zinc-air batteries(ZABs),it delivers a higher open-circuit voltage(1.514 V),a greater power density(223 mW cm^(−2)),and a larger specific capacity/energy than Pt/C-based counterparts.These results further highlight the potential of Fe1/SMC60 for practical energy devices associated with ORR and the importance of size-controlled synthesis of SMCs.展开更多
The exploration of active and long-lived oxygen reduction reaction(ORR)catalysts for the commercialization of zinc-air batteries are of immense significance but challenging.Herein,the sulfur doped FeWO_(4)embedded in ...The exploration of active and long-lived oxygen reduction reaction(ORR)catalysts for the commercialization of zinc-air batteries are of immense significance but challenging.Herein,the sulfur doped FeWO_(4)embedded in the multi-dimensional nitrogen-doped carbon structure(S-FeWO_(4)/NC)was successfully synthesized.The doped S atoms optimized the charge distribution in FeWO_(4)and enhanced the intrinsic activity.At the same time,S doping accelerated the formation of reaction intermediates during the adsorption reduction of O_(2)on the surface of S-FeWO_(4)/NC.Accordingly,the S-FeWO_(4)/NC catalyst showed more positive half-wave potential(0.85 V)and better stability than that of the FeWO_(4)/NC catalyst.Furthermore,the S-FeWO_(4)/NC-based zinc-air battery exhibited considerable power density of 150.3m W cm^(-2),high specific capacity of 912.7 m A h g^(-1),and prominent cycle stability up to 220 h.This work provides an assistance to the development of cheap and efficient tungsten-based oxygen reduction catalysts and the promotion of its application in the zinc-air battery.展开更多
Due to the poor Fenton reactivity,single-atom Mn-based materials are generally identified as one of the most promising active catalysts for oxygen reduction reaction(ORR).Regulating the electronic density and coordina...Due to the poor Fenton reactivity,single-atom Mn-based materials are generally identified as one of the most promising active catalysts for oxygen reduction reaction(ORR).Regulating the electronic density and coordination environment of atomically dispersed Mn centers is an effective strategy to enhance ORR activity of Mn-based materials.By introducing Zn sites,atomically dispersed Mn centers with multitudes of coordination(including Zn/Mn–Nx and Mn–Nx moieties)can be constructed to form Mn-based ORR catalyst(Zn/Mn-NC)with dual-atom sites.Around Mn–Nx sites,the Zn atoms can effectively modulate the electronic structure and coordination state of Mn centers in Zn/Mn-NC through d–d orbital coupling.The electronic interaction between Zn and Mn sites improves ORR activity,thereby optimizing the oxygen adsorption energy of Mn sites in Zn/Mn-NC and reducing the overall energy barrier.Zn/Mn-NC displays higher ORR half-wave potential than Pt/C(0.89 V vs 0.86 V).The quasi-solid-state zinc-air battery(ZAB)with Zn/Mn-NC as the cathode displayed excellent rechargeability,recyclability,and mechanical robustness.The strategy presented regulates the electronic density and coordination environment of singleatom Mn-based ORR catalysts in quasi-solid-state ZABs.展开更多
Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-...Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-metal catalysts hinder the practical applications of ZABs.Therefore,feasible and advanced non-noble-metal elec-trocatalysts for air cathodes need to be identified to promote the oxygen catalytic reaction.In this review,we initially introduced the advancement of ZABs in the past two decades and provided an overview of key developments in this field.Then,we discussed the work-ing mechanism and the design of bifunctional electrocatalysts from the perspective of morphology design,crystal structure tuning,interface strategy,and atomic engineering.We also included theoretical studies,machine learning,and advanced characterization technologies to provide a comprehensive understanding of the structure-performance relationship of electrocatalysts and the reaction pathways of the oxygen redox reactions.Finally,we discussed the challenges and prospects related to designing advanced non-noble-metal bifunctional electrocatalysts for ZABs.展开更多
Rationally 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 CoSe_(...Rationally 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 CoSe_(2)@NC@NCNFs bifunctional catalyst was designed and fabricated by confining cubic CoSe_(2)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 CoSe_(2)sites and Co-Nx-C sites can effectively enhance electron/mass transfer and reduce the diffusion resistance.The as-constructed CoSe_(2)@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 CoSe_(2)@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.展开更多
The development of efficient and inexpensive graphene-based electrocatalysts is of great significance to promote the commercial application of fuel cell and metal-air batteries. In this paper, a new type of Co and N c...The development of efficient and inexpensive graphene-based electrocatalysts is of great significance to promote the commercial application of fuel cell and metal-air batteries. In this paper, a new type of Co and N co-doped graphene-like nanocarbon(Co/N-GLC) material was prepared by nano-silicon protection and high temperature pyrolysis.The obtained Co/N-GLC catalyst not only has a similar morphology of graphene, but also possesses a high specific surface area(809 m2 g-1) with hierarchical porous structure(micropores/mesopores), and relative high active dopants content.These properties endow it with a good oxygen reduction activity in alkaline media, which can be comparable to commercial Pt/C catalyst. Moreover, the assembled zinc-air batteries using Co/N-GLC catalyst as the air electrode display a better discharge performance and higher stability compared to that of Pt/C electrode. This work demonstrates that the prepared graphene-like carbon catalyst has a good prospect,which can replace noble metal catalyst at the cathode in metalair batteries.展开更多
As an oxygen reduction reaction(ORR)catalyst,nitrogen-doped carbon(NC)is widely used in zinc-air batteries(ZABs).However,NC catalysts exhibit low conductivity and insufficient exposure of active sites.Therefore,a Co-b...As an oxygen reduction reaction(ORR)catalyst,nitrogen-doped carbon(NC)is widely used in zinc-air batteries(ZABs).However,NC catalysts exhibit low conductivity and insufficient exposure of active sites.Therefore,a Co-based deep eutectic solvent(DES)was selected to modify NC catalyst(Co-NC)to improve ORR performances.Density functional theory(DFT)calculation shows that the modification of Co-based DES can change the electronic structure of NC and increase metallic active sites,which is beneficial to the desorption of reaction intermediates on Co-NC,further improving ORR performance.Co-NC shows excellent ORR performances and stability.Impressively,ZABs assembled with Co-NC manifest a high maximum power density of 177.4 mW cm^(-2),a high specific capacity of 726.12 mA h g^(-1)and a charge-discharge cycle life of 500 h.This study can provide practical reference for surface modified carbon-based electrocatalyst with DES to improve ORR performances.展开更多
文摘Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） play a critical role in the operation of rechargeable zinc-air batteries. Herein, we report a simple and scalable strategy to fabricate porous carbon polyhedra using Zn-doped Co-based zeolitic imidazolate frameworks （ZnCo-ZIFs） as precursors. Strikingly, Zn doping leads to smaller Co nanoparticles and higher nitrogen content, which in turn enhances the ORR and OER activities of the obtained porous carbon polyhedra. The synergistic effect of the N-doped carbon and cobalt nanoparticles in the composite, the improved conductivity resulting from the high graphitization of carbon, and the large surface area of the porous polyhedral structure resulted in porous carbon polyhedra with excellent ORR and OER electrocatalytic activity in alkaline media. More importantly, air cathodes based on the optimal porous carbon polyhedra further exhibited superior performance to Pt/C catalysts in primary and rechargeable zinc-air batteries.
基金This study was financially supported by the Natural Science Foundation of China(Grant no.51825201 and 51772008)the National Key Research and Development Program of China(Grant no.2017YFA0206701)National Program for Support of Top-notch Young Professionals,and Changjiang Scholar Program.
文摘Metal-organic frameworks(MOFs)and MOF-derived materials have attracted great attention as alternatives to noble-metal based electrocatalysts owing to their intriguing structure properties,especially for high efficiency and stable oxygen reduction reaction(ORR).Herein,we employed a one-pot reaction to make a multimetal(Fe,Co,Cu,and Zn)mixed zeolitic imidazolate framework(MM-ZIF)via adopting a simple in situ redox reaction.Further pyrolysis of the target MM-ZIF,a highly porous carbon polyhedron(FC-C@NC)grafted with abundant carbon nanotubes was obtained,in which ultrasmall Co nanoparticles with partial lattice sites substituted by Fe and Cu were embedded.The obtained FC-C@NC possessed large surface area,highly porous structure,widely-spread metal active sites,and conductive carbon frameworks,contributing to outstanding ORR activity and long-term stability.It displayed superior tolerance to methanol crossover and exceeded the commercial Pt/C catalyst and most previously reported non-noble-metal catalysts.Impressively,the as-produced FC-C@NC-based zinc-air battery afforded an open-circuit potential of 1.466 V,a large specific capacity of 659.5 mAh/g,and a high gravimetric energy density of 784.3 Wh/kgZn,significantly outperforming the Pt/C-based cathode.
基金financially supported by the National Natural Science Foundation of China(21701101)the National Key Research and Development Project,Key Projects of Intergovernmental International Innovation Cooperation(2018YFE0118200 and 2016YFF0204402)+4 种基金the Fundamental Research Funds for the Central Universities(18CX06063A)the Key Research and Development Project of Shandong Province(2019JZZY010506)the Scientific Research Awards Foundation for Outstanding Young Scientists of Shandong Province(ZR2018JL010)the Joint Fund of Outstanding Young Talents of Shandong Province(ZR2017BB018)the Program of Qingdao Scientific and Technological Innovation High-level Talents Project(172-1-1-zhc)。
文摘An atomically dispersed FeCo-NC material with the 3D flower-like morphology was used as a unique substrate for the controllable deposition of ultrasmall NiFe layered double hydroxide nanodots(termed as NiFe-NDs)to simultaneously promote the sluggish kinetics of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).The size-limiting growth of NiFe-NDs(~4.0 nm in diameter)was realized via the confinement of the 3D flower-like mesoporous structure and the rich N/O functionality of FeCo-NC.Benefiting from the distinctive structure with the simultaneously maximum exposure of both OER and ORR active sites,the NiFe-ND/FeCo-NC composite showed an ORR halfwave potential of 0.85 V and an OER potential of 1.66 V in0.1 mol L-1KOH at 10.0 mA cm-2.In-situ Raman analysis suggested the activity of OER was derived from the Ni sites on NiFe-ND/FeCo-NC.Moreover,the NiFe-ND/FeCo-NC-assembled Zn-air battery(ZAB)exhibited a very small discharge-charge voltage gap of 0.87 V at 20 mA cm-2and robust cycling stability.Furthermore,the NiFe-ND/FeCo-NC composite was also applicable for fabricating all-solid-state ZAB to power wearable electronics with superior cycling stability under deformation.Our work could enlighten a new applicable branch of atomically dispersed metal-nitrogen-carbon materials as unique substrates for fabricating multifunctional electrocatalysts.
基金supported by the Shenzhen Government’s Plan of Science and Technology(JCYJ20190808121407676 and 20200813142301001)National Natural Science Foundation of China(22178223 and 22262010)+1 种基金Guangxi Science and Technology Fund for Distinguished High-Talent Introduction Program(No.RZ2200002233AC22035091).
文摘Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution reactions(OER).Herein,we fabricate a range of bifunctional M-N-C(metal-nitrogen-carbon)catalysts containing M-Nx coordination sites and M/MxC nanoparticles(M=Co,Fe,and Cu)using a new class ofγ-cyclodextrin(CD)based metal-organic framework as the precursor.With the two types of active sites interacting with each other in the catalysts,the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave(E1/2)potential(~0.917 and 0.906 V,respectively),which are higher than Cu@C-CuNC(~0.829 V)and the commercial Pt/C(~0.861 V).As a bifunctional electrocatalyst,the Co@C-CoNC exhibits the best performance,showing a bifunctional ORR/OER overpotential(ΔE)of~0.732 V,which is much lower than that of Fe@C-FeNC(~0.831 V)and Cu@C-CuNC(~1.411 V),as well as most of the robust bifunctional electrocatalysts reported to date.Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER,resulting in an enhanced bifunctional electrocatalytic performance.The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm^(−2) at 270.30 mA cm^(−2),higher than the combination of commercial Pt/C+RuO2(~158.90 mW cm^(−2) at 265.80 mA cm^(−2))catalysts.During the galvanostatic discharge at 10 mA cm^(−2),the ZAB delivered an almost stable discharge voltage of 1.2 V for~140 h,signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.
基金This work was financially supported by the National Natural Science Foundation of China(No.21701101)the National Key Research and Development Project(Nos.2018YFE0118200,2016YFF0204402)+5 种基金the Fundamental Research Funds for the Central Universities(No.18CX06063A)the Long-Term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of China,the Shandong Key Research and Development Project(No.2019JZZY010506)the Shandong Scientific Research Awards Foundation for Outstanding Young Scientists(No.ZR2018JL010)the Shandong Joint Fund of Outstanding Young Talents(No.ZR2017BB018)the Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(No.2017RCJJ059)the Program for Tsingtao Al-ion Power and Energy-Storage Battery Research Team in the University(No.17-2-1-1-zhc).
文摘Carbon materials featuring hierarchical pores and atomically dispersed metal sites are promising catalysts for energy storage and conversion applications.Herein,we developed a facile strategy to construct functional carbon materials with a fluffy peony-like structure and dense binary FeCo-Nx active sites(termed as f-FeCo-CNT).By regulating the metal content in precursors,a three-dimensional(3D)interconnected conductive carbon nanotubes network was in-situ formed throughout the atomically dispersed FeCo-NC matrix during pyrolysis.Taking advantage of rich pore hierarchy and co-existence of highly active FeCo-Nx sites and beneficial FeCo alloy nanoparticles,the f-FeCo-CNT material exhibited excellent bifunctional performance towards oxygen reduction reaction/oxygen evolution reactions(ORR/OER)with respect to the atomically dispersed FeCo-NC(SA-f-FeCo-NC)and commercial Pt/C+Ru02 mixture,surpassing the SA-f-FeCo-NC with a 20 mV higher ORR half-wave potential and a 100 mV lower OER overpotential(at 10.0 mA/cm^2).Remarkably,the f-FeCo-CNT-assembled Zn-air battery(ZAB)possessed a maximum specific power of 195.8 mW/cm^2,excellent rate capability,and very good cycling stability at large current density of 20.0 mA/cm^2.This work provides a facile and feasible synthetic strategy of constructing low-cost cathode materials with excellent comprehensive ZAB performance.
基金This study was supported by the National Science Foundation for Excellent Young Scholar(51722403)National Natural Science Foundation of China(51771134)+2 种基金Tianjin Natural Science Foundation for Distinguished Young Scholar(18JCJQJC46500)National Natural Science Foundation of China and Guangdong Province(U1601216)the National Youth Talent Support Program.
文摘Rechargeable zinc-air batteries(ZABs)have attracted much attention as the next-generation energy conversion and storage devices due to the abundance and environmental friendliness of zinc(Zn)for anode materials,as well as the safety and low cost of aqueous electrolytes.However,rational design of nonprecious and low-cost integrated air cathode materials with a desirable bifunctional oxygen electrocatalytic performance remains a great challenge for the commercialization of rechargeable ZABs.In previous research studies,various cost-effective carbon-supported electrocatalysts and light-weight carbon-based current collectors for air cathodes have been developed,showing vast potential in the application of carbon-based materials.To improve the bifunctional performance and integration of air cathodes,efforts with respect to the design of morphology,defects,and synergistic effects of carbon-based materials have been made.In this perspective,the general understanding of the air cathode construction and the battery working mechanism is discussed.The recent progress in the design of carbon-based materials for air cathodes in rechargeable ZABs is summarized.Several possible future research directions and the expected development trends are also discussed,aiming to facilitate the commercialization of advanced rechargeable ZABs in our life.
基金This work is supported by the National Natural Science Foundation of China(22075092)the Program for HUST Academic Frontier Youth Team(2018QYTD15).
文摘Oxygen electrocatalysts are of great importance for the air electrode in zinc-air batteries(ZABs).Owing to the high specific surface area,controllable pore size and unsaturated metal active sites,metal-organic frameworks(MOFs)derivatives have been widely studied as oxygen electrocatalysts in ZABs.To date,many strategies have been developed to generate efficient oxygen electrocatalysts from MOFs for improving the performance of ZABs.In this review,the latest progress of the MOF-derived non-noble metal-oxygen electrocatalysts in ZABs is reviewed.The performance of these MOF-derived catalysts toward oxygen reduction,and oxygen evolution reactions is discussed based on the categories of metal-free carbon materials,single-atom catalysts,metal cluster/carbon composites and metal compound/carbon composites.Moreover,we provide a comprehensive overview on the design strategies of various MOF-derived non-noble metal-oxygen electrocatalysts and their structure-performance relationship.Finally,the challenges and perspectives are provided for further advancing the MOF-derived oxygen electrocatalysts in ZABs.
基金supported by the National Basic Research Program of China (973 Program, 2015CB351903)the National Key Research and Development Program (2017YFA0207301)+1 种基金the National Natural Science Foundation of China (51402282, 21474095 and 21476104)CAS Key Research Program of Frontier Sciences (QYZDB-SSW-SLH018)
文摘Developing low-cost, high-performance elec- trocatalysts for the oxygen reduction reaction （ORR） is crucial for implementation of fuel cells and metal-air batteries into practical applications. Graphene-based catalysts have been extensively investigated for ORR in alkaline electrolytes. However, their performance in acidic electrolytes still requires further improvement compared to the Pt/C catalyst. Here we report a self-templating approach to prepare graphene-based sandwich-like porous carbon nanosheets for efficient ORR in both alkaline and acidic electrolytes. Graphene oxides were first used to adsorb m-phenylenediamine molecules which can form a nitrogen-rich polymer network after oxidative poly- merization. Then iron （Fe） salt was introduced into the polymer network and transformed into ORR active Fe-N-C sites along with Fe, FeS, and FEN0.05 nanopartides after pyr- olysis, generating ORR active sandwich-like carbon na- nosheets. Due to the presence of multiple ORR active sites. The as-obtained catalyst exhibited prominent ORR activity with a half-wave potential -30 mV more positive than Pt/C in 0.1 mol L-1 KOH, while the half-wave potential of the catalyst was only -40 mV lower than that of commercial Pt/C in 0.1 mol L-1 HClO4. The unique planar sandwich-like structure could expose abundant active sites for ORR. Meanwhile, the graphene layer and porous structure could simultaneously enhance electrical conductivity and facilitate mass transport. The prominent electrocatalytic activity and durability in both alkaline and acidic electrolytes indicate that these carbon na- nosheets hold great potential as alternatives to precious metal- based catalysts, as demonstrated in zinc-air batteries and proton exchange membrane fuel cells.
基金the German Research Foundation(DFG:LE 2249/15-1)the Sino-German Center for Research Promotion(GZ1579)Y.R.and C.F.X.would like to appreciate the support from the China Scholarship Council(Nos.202207030010 and 20210637004).
文摘Zinc-air batteries(ZABs)are widely studied because of their high theoretical energy density,high battery voltage,environmental protection,and low price.However,the slow kinetics of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)on the air electrode limits the further application of ZABs,so that how to develop a cheap,efficient,and stable catalyst with bifunctional catalytic activity is the key to solving the development of ZABs.Transition metal compounds are widely used as cathode materials for ZABs due to their low cost,high electrocatalytic activity,and stable structure.This review summarizes the research progress of transition metal compounds as bifunctional catalysts for ZABs.The development history,operation principle,and mechanism of ORR and OER reactions are introduced first.The application and development of transition metal compounds as bifunctional catalysts for ZABs in recent years are systematically introduced,including transition metal oxides(TMOs),transition metal nitrides(TMNs),transition metal sulfides(TMSs),transition metal carbides(TMCs),transition metal phosphates(TMPs),and others.In addition,the shortcomings of transition metal compounds as bifunctional catalysts for ZABs were summarized and reasonable design strategies and improvement measures were put forward,aiming at providing a reference for the design and construction of high-performance ZABs cathode materials.Finally,the challenges and future in this field are discussed and prospected.
基金This work was supported by the Hainan Provincial Natural Science Foundation of China(211RC1018)the National Natural Science Foundation of China(22109034,22109035,52164028,62105083)+2 种基金Hainan Province Science and Technology Special Fund(ZDYF2021GXJS207,ZDYF2020037,ZDYF2020207)Natural Science Foundation of Shaanxi Province(2020JZ-23)the Start-up Research Foundation of Hainan University((KYQD(ZR)-20008,20082,20083,20084,21065,21124,21125).Appendix A.Supplementary data。
文摘Robust oxygen reduction reaction(ORR)catalysts are essential for energy storage and conversion devices,but their development remains challenging.Herein,we design a single-atom catalyst featuring isolated Co anchored on nitrogen-doped carbon(Co-SAC/NC)via a highly efficient“plasma-bombing”strategy.With a high loading(up to 2.5wt%),the well-dispersed single Co atoms in Co-SAC/NC give it robust ORR performance in an alkaline medium.It also demonstrates excellent battery performance when implemented as the air-cathode catalyst in a zinc-air battery(ZAB).Theoretical calculations reveal that the Co-N_(4)moiety experiences an“extraction/recovery”structural evolution during the ORR process,and the reaction's rate-determining step is the formation of OOH∗(reaction intermediate).This work provides a new strategy for designing robust ORR catalysts for high-performance ZABs and other energy-conversion devices.
基金supported by the National Natural Science Foundation of China (51871119 and 51901100)the High-Level Entrepreneurial and Innovative Talents Program of Jiangsu Province,Jiangsu Provincial Funds for Natural Science Foundation (BK20170793 and BK20180015)+2 种基金the Six Talent Peak Project of Jiangsu Province (2018-XCL-033)China Postdoctoral Science Foundation (2018M640481 and 2019T120426)the Foundation of Graduation Innovation Center in NUAA (kfjj20190609)。
文摘The demanding all-in-one electrocatalyst system for oxygen reduction reaction(ORR), oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) in zinc-air batteries or water splitting requires elaborate material manufacturing, which is usually complicated and time-consuming.Efficient interface engineering between MXene and highly active electrocatalytic species(CoS_(2)) is, herein, achieved by an in situ hydrothermal growth and facile sulfurization process.The CoS_(2)@MXene electrocatalyst is composed by one-dimensional CoS_(2) nanowires and two-dimensional MXene nanosheets, which lead to a hierarchical structure(large specific surface area and abundant active sites), a spatial electron redistribution(high intrinsic activity), and high anchoring strength(superior performance stability). Therefore, the electrocatalyst achieves enhanced catalytic activity and longtime stability for ORR(a half-wave potential of 0.80 V), OER(an overpotential of 270 mV at 10 mA cm^(-2), i.e., η10= 270 mV)and HER(η10= 175 mV). Furthermore, the asymmetry water splitting system based on the CoS_(2)@MXene composites delivers a low overall voltage of 1.63 V at 10 mA cm^(-2). The solidstate zinc-air batteries using CoS_(2)@MXene as the air cathode display a small charge-discharge voltage gap(0.53 V at1 mA cm^(-2)) and superior stability(60 circles and 20-h continuous test). The energy interconversion between the chemical energy and electricity can be achieved by a self-powered system via integrating the water splitting system and quasisolid-state zinc-air batteries. Supported by in situ Raman analyses, the formation of cobalt oxyhydroxide species provides the active sites for water oxidation. This study paves apromising avenue for the design and application of multifunctional nanocatalysts.
基金support of the Fundamental Research Funds for the Central Universities(No.40120631)National Natural Science Foundation of China(No.52202291)for the support.
文摘Zn-air batteries(ZABs)as a class of promising energy storage setups are generally powered by efficient and robust catalysts at the oxygen-involving cathode.Although the existing non-noble catalysts have outperformed noble Pt benchmark in the alkaline liquid-state ZABs,to the best of our knowledge few have excelled Pt in quasi-solid-state(QSS)ZABs.Herein,we found that an integrated Mn-Co cathode derived from the bimetallic Mn/Co metal organic frameworks generates a 1.4-fold greater power density in the QSS ZABs than a Pt cathode while its power density in liquid-state ZABs is only 0.8-fold of the latter.Moreover,such Mn-Co catalyst delivers high-rate oxygen reduction reaction(ORR)capability with half-wave potential of 0.84 V.The in-depth characterizations and analyses have demonstrated that the Co and Mn species show the specific affinity towards H_(2)O and O_(2),respectively,synergizing the ORR process in the water-deficient environment of QSS ZABs.This work has enlightened the rational design of non-noble metal catalysts to improve the power density of QSS ZABs.
基金supported by the National Natural Science Foundation of China(22072107,21872105)the Natural Science Foundation of Shanghai(23ZR1464800)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Science&Technology Commission of Shanghai Municipality(19DZ2271500)。
文摘Smart wearable devices are regarded to be the next prevailing technology product after smartphones and smart homes,and thus there has recently been rapid development in flexible electronic energy storage devices.Among them,flexible solid-state zinc-air batteries have received widespread attention because of their high energy density,good safety,and stability.Efficient bifunctional oxygen electrocatalysts are the primary consideration in the development of flexible solid-state zinc-air batteries,and self-supported air cathodes are strong candidates because of their advantages including simplified fabrication process,reduced interfacial resistance,accelerated electron transfer,and good flexibility.This review outlines the research progress in the design and construction of nanoarray bifunctional oxygen electrocatalysts.Starting from the configuration and basic principles of zinc-air batteries and the strategies for the design of bifunctional oxygen electrocatalysts,a detailed discussion of self-supported air cathodes on carbon and metal substrates and their uses in flexible zinc-air batteries will follow.Finally,the challenges and opportunities in the development of flexible zinc-air batteries will be discussed.
基金supported by Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant(ZR2022ZD30)Qingdao New Energy Shandong Laboratory Open Project(Grant:QNESL OP 202307)+2 种基金Natural Science Foundation of Shandong Province(ZR2023QB103)China Postdoctoral Science Foundation(2023M733609)Qingdao Postdoctoral Applied Research Project(QDBSH20230202075).
文摘The rational design of Fe–N–C catalysts that possess easily accessible active sites and favorable mass transfer,which are usually determined by the structure of catalyst supports,is crucial for the oxygen reduction reaction(ORR).In this study,an oleic acid-assisted soft-templating approach is developed to synthesize size-controlled nitrogen-doped carbon nanoparticles(ranging from 130 nm to 60 nm and 35 nm,respectively)that feature spiral mesopores on their surface(SMCs).Next,atomically dispersed Fe–Nx sites are fabricated on the size-tunable SMCs(Fe1/SMC-x,where x represents the SMC size)and the size-dependent activity toward ORR is investigated.It is found that the catalytic performance of Fe1/SMCs is significantly influenced by the size of SMCs,where the Fe1/SMC-60 catalyst shows the highest ORR activity with a half-wave potential of 0.90 V vs.RHE in KOH electrolyte,indicating that the gas-liquid-solid three-phase interface on the Fe1/SMC-60 enhances the accessibility of Fe–Nx sites.In addition,when using Fe1/SMC-60 as the cathode catalyst in aqueous zinc-air batteries(ZABs),it delivers a higher open-circuit voltage(1.514 V),a greater power density(223 mW cm^(−2)),and a larger specific capacity/energy than Pt/C-based counterparts.These results further highlight the potential of Fe1/SMC60 for practical energy devices associated with ORR and the importance of size-controlled synthesis of SMCs.
基金the support of the National Natural Science Foundation of China(Nos.22178148,U21A20328)the Natural Science Foundation of Jiangsu Province(No.BK20191430)+2 种基金the Six Talent Peaks Project in Jiangsu Province(No.XNY-009)the Jiangsu Province and Education Ministry CoSponsored Synergistic Innovation Center of Modern Agricultural Equipment(No.XTCX2029)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The exploration of active and long-lived oxygen reduction reaction(ORR)catalysts for the commercialization of zinc-air batteries are of immense significance but challenging.Herein,the sulfur doped FeWO_(4)embedded in the multi-dimensional nitrogen-doped carbon structure(S-FeWO_(4)/NC)was successfully synthesized.The doped S atoms optimized the charge distribution in FeWO_(4)and enhanced the intrinsic activity.At the same time,S doping accelerated the formation of reaction intermediates during the adsorption reduction of O_(2)on the surface of S-FeWO_(4)/NC.Accordingly,the S-FeWO_(4)/NC catalyst showed more positive half-wave potential(0.85 V)and better stability than that of the FeWO_(4)/NC catalyst.Furthermore,the S-FeWO_(4)/NC-based zinc-air battery exhibited considerable power density of 150.3m W cm^(-2),high specific capacity of 912.7 m A h g^(-1),and prominent cycle stability up to 220 h.This work provides an assistance to the development of cheap and efficient tungsten-based oxygen reduction catalysts and the promotion of its application in the zinc-air battery.
基金support of the National Natural Science Foundation of China(grant nos.22278193 and 22178148)Jiangsu Province and Education Ministry Cosponsored Synergistic Innovation Center of Modern Agricultural Equipment(grant no.XTCX2029)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Due to the poor Fenton reactivity,single-atom Mn-based materials are generally identified as one of the most promising active catalysts for oxygen reduction reaction(ORR).Regulating the electronic density and coordination environment of atomically dispersed Mn centers is an effective strategy to enhance ORR activity of Mn-based materials.By introducing Zn sites,atomically dispersed Mn centers with multitudes of coordination(including Zn/Mn–Nx and Mn–Nx moieties)can be constructed to form Mn-based ORR catalyst(Zn/Mn-NC)with dual-atom sites.Around Mn–Nx sites,the Zn atoms can effectively modulate the electronic structure and coordination state of Mn centers in Zn/Mn-NC through d–d orbital coupling.The electronic interaction between Zn and Mn sites improves ORR activity,thereby optimizing the oxygen adsorption energy of Mn sites in Zn/Mn-NC and reducing the overall energy barrier.Zn/Mn-NC displays higher ORR half-wave potential than Pt/C(0.89 V vs 0.86 V).The quasi-solid-state zinc-air battery(ZAB)with Zn/Mn-NC as the cathode displayed excellent rechargeability,recyclability,and mechanical robustness.The strategy presented regulates the electronic density and coordination environment of singleatom Mn-based ORR catalysts in quasi-solid-state ZABs.
基金the Natural Science Foundation of China(Grant No:22309180)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No:XDB0600000,XDB0600400)+3 种基金Liaoning Binhai Laboratory,(Grant No:LILBLB-2023-04)Dalian Revitalization Talents Program(Grant No:2022RG01)Youth Science and Technology Foundation of Dalian(Grant No:2023RQ015)the University of Waterloo.
文摘Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-metal catalysts hinder the practical applications of ZABs.Therefore,feasible and advanced non-noble-metal elec-trocatalysts for air cathodes need to be identified to promote the oxygen catalytic reaction.In this review,we initially introduced the advancement of ZABs in the past two decades and provided an overview of key developments in this field.Then,we discussed the work-ing mechanism and the design of bifunctional electrocatalysts from the perspective of morphology design,crystal structure tuning,interface strategy,and atomic engineering.We also included theoretical studies,machine learning,and advanced characterization technologies to provide a comprehensive understanding of the structure-performance relationship of electrocatalysts and the reaction pathways of the oxygen redox reactions.Finally,we discussed the challenges and prospects related to designing advanced non-noble-metal bifunctional electrocatalysts for ZABs.
基金supported by the National Natural Science Foundation of China(Nos.52174286,22105190)Natural Science Foundation of Hunan Province in China(2023JJ10068)Innovation-Driven Project of Central South University(No.2020CX007).
文摘Rationally 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 CoSe_(2)@NC@NCNFs bifunctional catalyst was designed and fabricated by confining cubic CoSe_(2)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 CoSe_(2)sites and Co-Nx-C sites can effectively enhance electron/mass transfer and reduce the diffusion resistance.The as-constructed CoSe_(2)@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 CoSe_(2)@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.
基金supported by the National Natural Science Foundation of China (51602113 and 51702111)China Postdoctoral Science Foundation (2016M590692)
文摘The development of efficient and inexpensive graphene-based electrocatalysts is of great significance to promote the commercial application of fuel cell and metal-air batteries. In this paper, a new type of Co and N co-doped graphene-like nanocarbon(Co/N-GLC) material was prepared by nano-silicon protection and high temperature pyrolysis.The obtained Co/N-GLC catalyst not only has a similar morphology of graphene, but also possesses a high specific surface area(809 m2 g-1) with hierarchical porous structure(micropores/mesopores), and relative high active dopants content.These properties endow it with a good oxygen reduction activity in alkaline media, which can be comparable to commercial Pt/C catalyst. Moreover, the assembled zinc-air batteries using Co/N-GLC catalyst as the air electrode display a better discharge performance and higher stability compared to that of Pt/C electrode. This work demonstrates that the prepared graphene-like carbon catalyst has a good prospect,which can replace noble metal catalyst at the cathode in metalair batteries.
基金supported by the National Natural Science Foundation of China(No,22278193)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘As an oxygen reduction reaction(ORR)catalyst,nitrogen-doped carbon(NC)is widely used in zinc-air batteries(ZABs).However,NC catalysts exhibit low conductivity and insufficient exposure of active sites.Therefore,a Co-based deep eutectic solvent(DES)was selected to modify NC catalyst(Co-NC)to improve ORR performances.Density functional theory(DFT)calculation shows that the modification of Co-based DES can change the electronic structure of NC and increase metallic active sites,which is beneficial to the desorption of reaction intermediates on Co-NC,further improving ORR performance.Co-NC shows excellent ORR performances and stability.Impressively,ZABs assembled with Co-NC manifest a high maximum power density of 177.4 mW cm^(-2),a high specific capacity of 726.12 mA h g^(-1)and a charge-discharge cycle life of 500 h.This study can provide practical reference for surface modified carbon-based electrocatalyst with DES to improve ORR performances.
