Dendrite formation severely compromises further development of zinc ion batteries. Increasing the nucleation overpotential plays a crucial role in achieving uniform deposition of metal ions. However, this strategy has...Dendrite formation severely compromises further development of zinc ion batteries. Increasing the nucleation overpotential plays a crucial role in achieving uniform deposition of metal ions. However, this strategy has not yet attracted enough attention from researchers to our knowledge. Here, we propose that thermodynamic nucleation overpotential of Zn deposition can be boosted through complexing agent and select sodium L-tartrate(Na-L) as example. Theoretical and experimental characterization reveals L-tartrate anion can partially replace H_(2)O in the solvation sheath of Zn^(2+), increasing de-solvation energy. Concurrently, the Na^(+) could absorb on the surface of Zn anode preferentially to inhibit the deposition of Zn^(2+) aggregation. In consequence, the overpotential of Zn deposition could increase from 32.2 to 45.1 mV with the help of Na-L. The Zn-Zn cell could achieve a Zn utilization rate of 80% at areal capacity of 20 mAh cm^(-2). Zn-LiMn_(2)O_(4) full cell with Na-L additive delivers improved stability than that with blank electrolyte. This study also provides insight into the regulation of nucleation overpotential to achieve homogeneous Zn deposition.展开更多
Generating sufficient strains on metal surfaces are highly challenging owing to that most metals can deform plastically to relax the strains on the surfaces.In this work,we developed a facile but highly efficient stac...Generating sufficient strains on metal surfaces are highly challenging owing to that most metals can deform plastically to relax the strains on the surfaces.In this work,we developed a facile but highly efficient stacked deposition strategy to in situ activation and reconstruction of NiO/NiOOH on Ni matrix,following with the migration of Fe ions to NiOOH.The Fe sites on the Ni/NiO/NiOOH facilitate the formation of the stable*OH oxygenated intermediates,and the Ni matrix in the catalyst provides the catalyst excellent stability.The oxygen evolution reaction(OER)performance of the stacked NiFe-5 with compressive strain displays the strengthened binding to oxygenated intermediates and superior OER activity,the ultralow overpotentials of 162 versus reversible hydrogen electrode at 10 mA cm^(-2).On the other hand,the Ni-5 without the incorporation of Fe has shown an outstanding hydrogen evolution reaction(HER)activity,affording an overpotential of 47 mV at 10 mA cm^(-2).The NiFe-5‖Ni-5 enables the overall water splitting at a voltage of 1.508 V to achieve 20 mA cm^(-2) with remarkable durability.The stacked deposition strategy improves binding strength of Ni-based catalysts to oxygenated intermediates via generating compressive strain,causing high catalytic activities on OER and HER.展开更多
Achieving low charge overpotentials represents one of the most critical challenges for pursuing highperformance lithium-oxygen(Li-O_(2))batteries.Herein,we propose a strategy to realize low charge overpotentials by co...Achieving low charge overpotentials represents one of the most critical challenges for pursuing highperformance lithium-oxygen(Li-O_(2))batteries.Herein,we propose a strategy to realize low charge overpotentials by confining the growth of lithium peroxide(Li_(2)O_(2))inside mesoporous channels of cathodes(CMK-8).The CMK-8 cathode with tortuous pore structures can extend the diffusion distance of lithium superoxide(LiO_(2))in the mesoporous channels,facilitating the further reduction of LiO_(2) to lithium peroxide(Li_(2)O_(2))inside the pores and preventing them to be diffused out of the pores.Therefore,Li_(2)O_(2) is trapped in the mesoporous channels of CMK-8 cathodes,ensuring a good Li_(2)O_(2)/CMK-8 contact interface.The CMK-8 electrode exhibits a low charge overpotential of 0.43 V and a good cycle life for 72 cycles with a fixed capacity of 500 m Ah g^(-1) at 0.1 A g^(-1).This study proposes a strategy to achieve a low charge overpotential by confining Li_(2)O_(2) growth in the mesoporous channels of cathodes.展开更多
The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathod...The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathode catalysts with high activity and stability is crucial to overcome the terrible issues at high current density.Herein,we report a surface engineering strategy to adjust the surface electron structure of boron(B)‐doped PtNi nanoalloy on carbon nanotubes(PtNiB@CNTs)as an efficient bifunctional cathodic catalyst for high‐rate and long‐life Li‐O2 batteries.Notably,the Li‐O2 batteries assembled with as‐prepared PtNiB@CNT catalyst exhibit ultrahigh discharge capacity of 20510 mA·h/g and extremely low overpotential of 0.48 V at a high current density of 1000 mA/g,both of which outperform the most reported Pt‐based catalysts recently.Meanwhile,our Li‐O2 batteries offer excellent rate capability and ultra‐long cycling life of up to 210 cycles at 1000 mA/g under a fixed capacity of 1000 mA·h/g,which is two times longer than those of Pt@CNTs and PtNi@CNTs.Furthermore,it is revealed that surface engineering of PtNi nanoalloy via B doping can efficiently tailor the electron structure of nanoalloy and optimize the adsorption of oxygen species,consequently delivering excellent Li‐O2 battery performance.Therefore,this strategy of regulating the nanoalloy by doping nonmetallic elements will pave an avenue for the design of high‐performance catalysts for metal‐oxygen batteries.展开更多
CO_(2)electroreduction to formate is technically feasible and economically viable,but still suffers from low selectivity and high overpotential at industrial current densities.Here,lattice-distorted metallic nanosheet...CO_(2)electroreduction to formate is technically feasible and economically viable,but still suffers from low selectivity and high overpotential at industrial current densities.Here,lattice-distorted metallic nanosheets with disorder-engineered metal sites are designed for industrial-current-density CO_(2)-to-formate conversion at low overpotentials.As a prototype,richly lattice-distorted bismuth nanosheets are first constructed,where abundant disorder-engineered Bi sites could be observed by high-angle annular dark-field scanning transmission electron microscopy image.In-situ Fourier-transform infrared spectra reveal the CO_(2)•−*group is the key intermediate,while theoretical calculations suggest the electron-enriched Bi sites could effectively lower the CO_(2)activation energy barrier by stabilizing the CO_(2)•−*intermediate,further affirmed by the decreased formation energy from 0.49 to 0.39 eV.As a result,the richly lattice-distorted Bi nanosheets exhibit the ultrahigh current density of 800 mA·cm^(−2)with 91%Faradaic efficiencies for CO_(2)-to-formate electroreduction,and the formate selectivity can reach nearly 100%at the current density of 200 mA·cm^(−2)with a very low overpotential of ca.570 mV,outperforming most reported metal-based electrocatalysts.展开更多
Electrochemical CO_(2) reduction reaction(CO_(2)RR)into value-added chemicals/fuels is crucial for realizing the sustainable carbon cycle while mitigating the energy crisis.However,it is impeded by the relatively high...Electrochemical CO_(2) reduction reaction(CO_(2)RR)into value-added chemicals/fuels is crucial for realizing the sustainable carbon cycle while mitigating the energy crisis.However,it is impeded by the relatively high overpotential and low energy efficiency due to the lack of efficient electrocatalysts.Herein,we develop an isolated single-atom Ni catalyst regulated strategy to activate and stabilize the iron phthalocyanine molecule(Ni SA@FePc)toward a highly efficient CO_(2)RR process at low overpotential.The well-defined and homogenous catalytic centers with unique structures confer Ni SA@FePc with a significantly enhanced CO_(2)RR performance compared to single-atom Ni catalyst and FePc molecule and afford the atomic understanding on active sites and catalytic mechanism.As expected,Ni SA@FePc exhibits a high selectivity of more significant Faraday efficiency(≥95%)over a wide potential range,a high current density of~252 mA·cm^(−2) at low overpotential(390 mV),and excellent long-term stability for CO_(2)RR to CO.X-ray absorption spectroscopy measurement and theoretical calculation indicate the formation of NiN_(4)-O_(2)-FePc heterogeneous structure for Ni SA@FePc.And CO_(2)RR prefers to occur at the raised N centers of NiN4-O_(2)-FePc heterogeneous structure for Ni SA@FePc,which enables facilitated adsorption of*COOH and desorption of CO,and thus accelerated overall reaction kinetics.展开更多
The pH gradient caused by H^(+)/OH^(−)transport on an electrode surface is the key factor determining reaction performance,but its detailed impact on the electrode reaction kinetics has yet to be clarified.Here,the pH...The pH gradient caused by H^(+)/OH^(−)transport on an electrode surface is the key factor determining reaction performance,but its detailed impact on the electrode reaction kinetics has yet to be clarified.Here,the pH gradient effect was determined by developing electrode reaction equations,considering the overpotential assigned to the pH gradient called pH overpotential.The pH gradient effect was revealed to involve two aspects:(1)the Nernst pH overpotential,accounting for the common Nernst relationship with pH,and(2)the pH-dependent function of the electron-transfer coefficient(α_(pH)).Both parts were verified experimentally using oxygen reduction reaction and hydrogen evolution reaction,obviously,with differentα_(pH) functions.Detailedα_(pH) function effect was clarified based on numerical calculations of the electrode reaction equations.We found that the effect could be assessed suitably by an apparent constant(α_(app))and a nonlinear fitting method proposed forα_(app) value estimation.The results of this study provide the kinetic fundamentals of electrode reactions involving H^(+)/OH^(−)and contribute to the understanding and assessment of their performance with the H^(+)/OH^(−)transport effect.展开更多
Since low overpotential for the anodic ethanol oxidation reaction(EOR)can favor the higher output voltage and power of direct ethanol fuel cells(DEFCs),it is critical to design new EOR catalysts with efficient ethanol...Since low overpotential for the anodic ethanol oxidation reaction(EOR)can favor the higher output voltage and power of direct ethanol fuel cells(DEFCs),it is critical to design new EOR catalysts with efficient ethanol-to-CO_(2)activity at low applied potentials.Thereby,carbon-supported Ir-Bi_(2)O_(3)(Ir-Bi_(2)O_(3)/C)catalysts with highly dispersive bismuth oxide on the iridium surface are designed and prepared,which can merit splitting the ethanol C–C bond and promoting the oxidation of C1 intermediates at the bifunctional interfaces.The as-obtained Ir-Bi2O3/C catalysts show superior EOR mass activity of up to ca.2250 m A mgIr-1.Moreover,they exhibit the record lowest onset oxidation potentials(0.17–0.22 V vs.RHE)and the peak potential(ca.0.58 V vs.RHE),being 130–300 m V lower than the previous landmark noble metallic catalysts.Furthermore,an apparent C1 pathway faraday efficiency(FEC1)of 28%±5.9%at 0.5 V vs.RHE can be obtained at Ir-Bi_(2)O_(3)/C.This work might provide new insights into the new anodic EOR catalysts for increasing the power of DEFCs.展开更多
Electrocatalytic nitrogen reduction reaction(NRR)at ambient conditions holds great promise for sustainably synthesizing ammonia(NH3),while developing highly-efficient,long-term stable,and inexpensive catalysts to acti...Electrocatalytic nitrogen reduction reaction(NRR)at ambient conditions holds great promise for sustainably synthesizing ammonia(NH3),while developing highly-efficient,long-term stable,and inexpensive catalysts to activate the inert N≡N bond is a key scientific issue.In this work,on the basis of the concept"N-heterocyclic carbenes(NHCs)",we propose a carbon decorated graphitic-carbon nitride(C/g-C3N4)as novel metal-free NRR electrocatalyst by means of density functional theory(DFT)computations.Our results reveal that the introduced C atom in g-C3N4 surface can be regarded as NHCs and catalytic sites for activating N≡N bond,and are stabilized by the g-C3N4 substrate due to sterically disfavored dimerization.Especially,this NHCs-based heterogeneous catalysis can efficiently reduce the activated N2 molecule to NH3 with a low overpotential of 0.05 V via an enzymatic mechanism.Our work is the first report of NHCs-based electrocatalyst for N2 fixation,thus opening an alternative avenue for advancing sustainable NH3 production.展开更多
In this study,commercial copper(Cu)foil and Cu foam are used as the working electrodes to systematically investigate the electrochemical deposition and dissolution processes of metallic lithium(Li)on these electrodes;...In this study,commercial copper(Cu)foil and Cu foam are used as the working electrodes to systematically investigate the electrochemical deposition and dissolution processes of metallic lithium(Li)on these electrodes;Li metal deposited on the Cu foil electrode is porous and loose.The surface solid electrolyte interface(SEI)film after dissolution from Li dendrites maintains a dendritic porous structure,resulting in a large volume effect of the electrode during the cycle.The Cu foam electrode provides preferential nucleation and deposition sites near the side surface of the separator;the difference in Li affinity results in a heterogeneous deposition and dendrite growth of metallic Li.展开更多
The design of cost-effective, highly active catalysts for hydrogen energy production is a vital element in the societal pursuit of sustainable energy. Water electrolysis is one of the most convenient processes to prod...The design of cost-effective, highly active catalysts for hydrogen energy production is a vital element in the societal pursuit of sustainable energy. Water electrolysis is one of the most convenient processes to produce high purity hydrogen. Cobalt-based catalysts are well-known electrocatalysts for oxygen evolution reaction(OER). In this article, all these merits indicate that the present cobalt nanocomposite is a promising electrocatalyst for OER. C–CoO-nanorods catalyst with nanorod structure was synthesized by hydrothermal treatment of CoCl·6HO/dextrose/urea mixture at 180 °C for 18 h and then calcined at400 °C for 3.5 h. The role of dextrose percentage in solution to achieve the uniform coating of carbon on the surface of CoO-nanorods has been demonstrated. The prepared materials were characterized by X-ray diffraction(XRD), X-ray photoelectron spectrum(XPS), field emission scanning electron microscopy(FE-SEM), high-resolution transmission electron microscopy(HR-TEM), and Brunauer–Emmett–Teller instrument(BET). Due to its unique morphology, the C–CoO-nanorods catalyst exhibited better activity than CoO-microplates catalyst for OER in 1 M KOH aqueous solution. The results showed a highly efficient, scalable, and low-cost method for developing highly active and stable OER electrocatalysts in alkaline solution.展开更多
In co-ionic conducting solid oxide fuel cell (SOFC), both oxygen ion (O2) and proton (H+) can transport through the electrolyte, generating steam in both the an-ode and cathode. Thus the mass transport phenomen...In co-ionic conducting solid oxide fuel cell (SOFC), both oxygen ion (O2) and proton (H+) can transport through the electrolyte, generating steam in both the an-ode and cathode. Thus the mass transport phenomenon in the electrodes is quite different from that in conventional SOFC with oxygen ion conducting electrolyte (O-SOFC) or with proton conducting electrolyte (H-SOFC). The generation of steam in both electrodes also affects the concentration over-potential loss and further the SOFC performance. However, no detailed modeling study on SOFCs with co-ionic electrolyte has been reported yet. In this paper, a new mathematical model for SOFC based on co-ionic electrolyte was developed to predict its actual performance considering three major kinds of overpotentials. Ohm's law and the Butler-Volmer formula were used to model the ion conduction and electrochemical reactions, respectively. The dusty gas model (DGM) was employed to simulate the mass transport processes in the porous electrodes. Parametric simulations were performed to investigate the effects of proton transfer number (tH) and current density (jtotal) on the cell performance. It is interesting to find that the co-ionic conducting SOFC could perform better than O-SOFC and H-SOFC by choosing an appropriate proton transfer number. In addition, the co-ionic SOFC shows smaller difference between the anode and cathode concentration overpotentials than O-SOFC and H-SOFC at certain t H values. The results could help material selection for enhancing SOFC performance.展开更多
Searching for efficient and robust non-noble electrocatalysts for hydrogen generation is extremely desirable for future green energy systems.Here, we present the synthesis of integrated Ni-P-S nanosheets array includi...Searching for efficient and robust non-noble electrocatalysts for hydrogen generation is extremely desirable for future green energy systems.Here, we present the synthesis of integrated Ni-P-S nanosheets array including Ni_2P and NiS on nickel foam by a simple simultaneous phosphorization and sulfurization strategy. The resultant sample with optimal composition exhibits superior electrocatalytic performance for hydrogen evolution reaction(HER) in a wide pH range. In alkaline media, it can generate current densities of 10, 20 and 100 mA cm^(-2) at low overpotentials of only-101.9,-142.0 and-207.8 mV with robust durability. It still exhibits high electrocatalytic activities even in acid or neutral media. Such superior electrocatalytic performances can be mainly attributed to the synergistic enhancement of the hybrid Ni-P-S nanosheets array with integration microstructure. The kind of catalyst gives a new insight on achieving efficient and robust hydrogen generation.展开更多
The iron-doped nickel oxide films used as oxygen evolution catalysts in the photoelectrochemical production of hydrogen from solar energy were deposited by means of RF reactive magnetron sputtering from a Ni-Fe alloy ...The iron-doped nickel oxide films used as oxygen evolution catalysts in the photoelectrochemical production of hydrogen from solar energy were deposited by means of RF reactive magnetron sputtering from a Ni-Fe alloy target in oxygen and argon atmosphere.The effects of processing parameters on the film properties,such as overpotential,composition,surface morphology and preferred orientation,were investigated.The electrochemical experiment,structural and compositional measurements indicate that the relative lower substrate temperature,higher RF power,higher working pressure and oxygen content are necessary to gain lower overpotential.The lowest overpotential of 251 mV is obtained at a current density of 80 mA/cm2.The existence of iron,which acts as activity site,and Ni3+ ion is responsible for lowering overpotential.By analyzing SEM and XRD data,it is also noticed that an improvement in crystallinity,appropriate grain size and less crystalline phase contribute to an increased electrocatalytic activity in oxygen evolution reaction.These results mentioned above indicate that iron-doped nickel oxide is promising as an oxygen catalyst.展开更多
Metal-organic frameworks(MOFs)exhibit excellent application potential in the field of electrocatalysis.In this study,we first prepare MIL-100 nanosheets on nickel foam(MIL-100/NF)and then successfully anchor Ag nanopa...Metal-organic frameworks(MOFs)exhibit excellent application potential in the field of electrocatalysis.In this study,we first prepare MIL-100 nanosheets on nickel foam(MIL-100/NF)and then successfully anchor Ag nanoparticles(NPs)on the nanosheets(Ag@MIL-100/NF)for oxygen evolution reaction(OER)catalysis.This strategy dramatically improves the conductivity of MIL-100 and the Ag NPs are uniformly dispersed on the nanosheets.The Ag@MIL-100/NF catalyst has excellent electrocatalytic performance and long-term corrosion resistance,with a low overpotential of 207 mV and a long-term stability of at least 100 h at a current density of 50 mA·cm^(-2).The experimental results demonstrate that this high OER catalytic performance is due to the improved charge transfer after loading Ag NPs,the combination of nanosheets and highly dispersed Ag NPs that expose more active sites and the adjusted chemical valence states of Fe and Ni in MIL-100.This work provides a surface decoration approach for the preparation of excellent catalysts directly used in the OER.展开更多
The society’s urgent demand for environmentally friendly, safe and low-cost energy storage devices has promoted the research of aqueous zinc-ion batteries. However, the uneven deposition of Zn ions on anodes will lea...The society’s urgent demand for environmentally friendly, safe and low-cost energy storage devices has promoted the research of aqueous zinc-ion batteries. However, the uneven deposition of Zn ions on anodes will lead to the growth of the dendrite and reduce the Coulombic efficiency as well as the lifespan of the devices. Herein, we construct an O,N-dual functionalized carbon cloth current collector via a simple hydrothermal strategy, in which the oxygen-containing functional groups and the N heteroatoms can regulate the transmission and deposition of Zn ions, respectively. The proposed synergistic strategy ensures the uniform distribution of Zn ions on the surface of the Zn anode and inhibits the formation of dendrites. The symmetric cell based on the O,N-dual doped carbon cloth presents superior cycling stability(318 h) with a low voltage hysteresis(11.2 mV) at an areal capacity of 1 m Ah cm^(-2)(20% depth of diacharge). Meanwhile, the appreciably low overpotential(16 m V) and high Columbic efficiency(98.2%)also demonstrate that the O,N-dual functionalized carbon cloth can be worked as a promising host for Zn ions deposition.展开更多
Nickel-metal hydride (Ni/MH) batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-te...Nickel-metal hydride (Ni/MH) batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-temperature-efficiency of nickel electrode, spherical nickel hydroxide mixed with various ratios of Lu2O3 was used as active material of pasted nickel electrodes. The results of charge/discharge experiments, cyclic voltammetric measurements and XRD characterizations have shown that after addition of Lu2O3, the oxygen evolution overpotcntial is elevated much, the charge efficiency of nickel electrode at high temperature is greatly improved and the content of β-NiOOH phase increases in charged electrodes. In addition, the mixed ratio of Lu2O3 has different effects on high temperature performances of nickel electrode at different charge/discharge currents, 3.5 % is the optimum mixed ratio, and the action of Lu2O3 on high temperature electrochemical behaviors is more apparent when nickel electrodes are charged at small current than large current.展开更多
Aprotic lithium–oxygen batteries(LOBs)have been recognized as novel energy storage devices for their outstanding specific energy density,while the large discharge/charge overpotential is a tough barrier to be overcom...Aprotic lithium–oxygen batteries(LOBs)have been recognized as novel energy storage devices for their outstanding specific energy density,while the large discharge/charge overpotential is a tough barrier to be overcome.Here,hetero-structured MoS_(2)/ZnIn_(2)S_(4) nanosheets have been prepared to capture visible light and the generated charge carriers are utilized for promoting both the oxygen reduction reaction and the oxygen evolution reaction.With the light illumination in the discharge process,the abundant photo-inspired electrons serve as the reaction sites to promote the reduction of O_(2) into LiO_(2) which is finally deposited as Li_(2)O_(2).On the contrary,the generated holes in the valence band can contribute to the low oxidization potential of Li_(2)O_(2) during the charge process.It delivers a low charge potential of 3.29 V,with an excellent resulting energy efficiency of 96.7%,much superior to that of 69.2%in the dark condition.It is noted that the involvement of photoelectrons has influenced the growth of Li_(2)O_(2) films on the MoS_(2)/ZnIn_(2)S_(4) nanosheets through the surface-adsorption pathway.The insights from the theoretical calculation confirm that the photoelectrons favor the absorption of LiO_(2) and the formation of the Li_(2)O_(2) film through the surface route.Therefore,this paper provides a deeper understanding of the mechanism of photoinspired charge carriers in LOBs and will enable further exploration of photo-involved energy storage systems.展开更多
A facile synthesis of Ag nanocrystals encapsulated in nitrogen-doped carbon fiber(NCF)is proposed,based on the simultaneous reaction between pyrrole and Ag^(+)ions in an aqueous solvent followed by a heat treatment.Th...A facile synthesis of Ag nanocrystals encapsulated in nitrogen-doped carbon fiber(NCF)is proposed,based on the simultaneous reaction between pyrrole and Ag^(+)ions in an aqueous solvent followed by a heat treatment.The as-prepared Ag/NCF demonstrated superior catalytic behavior toward ORR and OER.Besides improved cycling stability,a much lower discharge/charge gap of 0.89 V(vs Li/Li^(+))compared with 1.38 V for NCF cathode with a fixed capacity of 500 m Ah g^(-1)was obtained in lithium oxygen batteries.The introduction of Ag crystals into NCF facilitates the oxygen reduction reaction/oxygen evolution reaction kinetics.X-ray diffraction analysis coupled with Raman spectroscopy confirmed that Ag/NCF cathode could reversibly catalyze Li_(2)O_(2)formation and decomposition.The NCF matrix offers a conductive network to realize rapid mass transfer and the encapsulated Ag nanocrystals supplied effective catalytic active sites.The combined action between both contributes to the superior electrocatalytic performance.展开更多
基金supported by the National Key R&D Program of China (2022YFB3305400)Beijing Natural Science Foundation (Z220021)+3 种基金Science and Technology Innovation Program Talent Cultivation Project of Beijing Institute of Technology (2021CX01012)the National Natural Science Foundation of China (51972030, 22202011)Beijing Outstanding Young Scientists Program (BJJWZYJH01201910007023)Natural Science Foundation of Shandong Province (ZR2022QB056)。
文摘Dendrite formation severely compromises further development of zinc ion batteries. Increasing the nucleation overpotential plays a crucial role in achieving uniform deposition of metal ions. However, this strategy has not yet attracted enough attention from researchers to our knowledge. Here, we propose that thermodynamic nucleation overpotential of Zn deposition can be boosted through complexing agent and select sodium L-tartrate(Na-L) as example. Theoretical and experimental characterization reveals L-tartrate anion can partially replace H_(2)O in the solvation sheath of Zn^(2+), increasing de-solvation energy. Concurrently, the Na^(+) could absorb on the surface of Zn anode preferentially to inhibit the deposition of Zn^(2+) aggregation. In consequence, the overpotential of Zn deposition could increase from 32.2 to 45.1 mV with the help of Na-L. The Zn-Zn cell could achieve a Zn utilization rate of 80% at areal capacity of 20 mAh cm^(-2). Zn-LiMn_(2)O_(4) full cell with Na-L additive delivers improved stability than that with blank electrolyte. This study also provides insight into the regulation of nucleation overpotential to achieve homogeneous Zn deposition.
基金supported by the National Natural Science Foundations of China(21965024,22269016,51721002)the Inner Mongolia funding(2020JQ01,21300-5223601)the funding of Inner Mongolia University(10000-21311201/137,213005223601/003,21300-5223707)。
文摘Generating sufficient strains on metal surfaces are highly challenging owing to that most metals can deform plastically to relax the strains on the surfaces.In this work,we developed a facile but highly efficient stacked deposition strategy to in situ activation and reconstruction of NiO/NiOOH on Ni matrix,following with the migration of Fe ions to NiOOH.The Fe sites on the Ni/NiO/NiOOH facilitate the formation of the stable*OH oxygenated intermediates,and the Ni matrix in the catalyst provides the catalyst excellent stability.The oxygen evolution reaction(OER)performance of the stacked NiFe-5 with compressive strain displays the strengthened binding to oxygenated intermediates and superior OER activity,the ultralow overpotentials of 162 versus reversible hydrogen electrode at 10 mA cm^(-2).On the other hand,the Ni-5 without the incorporation of Fe has shown an outstanding hydrogen evolution reaction(HER)activity,affording an overpotential of 47 mV at 10 mA cm^(-2).The NiFe-5‖Ni-5 enables the overall water splitting at a voltage of 1.508 V to achieve 20 mA cm^(-2) with remarkable durability.The stacked deposition strategy improves binding strength of Ni-based catalysts to oxygenated intermediates via generating compressive strain,causing high catalytic activities on OER and HER.
基金the financial support from the National Natural Science Foundation of China(91645102)the Singapore MOE grant(R143-000-A29-112)the Hundred Talents Sailing Project of Jiangxi province,China。
文摘Achieving low charge overpotentials represents one of the most critical challenges for pursuing highperformance lithium-oxygen(Li-O_(2))batteries.Herein,we propose a strategy to realize low charge overpotentials by confining the growth of lithium peroxide(Li_(2)O_(2))inside mesoporous channels of cathodes(CMK-8).The CMK-8 cathode with tortuous pore structures can extend the diffusion distance of lithium superoxide(LiO_(2))in the mesoporous channels,facilitating the further reduction of LiO_(2) to lithium peroxide(Li_(2)O_(2))inside the pores and preventing them to be diffused out of the pores.Therefore,Li_(2)O_(2) is trapped in the mesoporous channels of CMK-8 cathodes,ensuring a good Li_(2)O_(2)/CMK-8 contact interface.The CMK-8 electrode exhibits a low charge overpotential of 0.43 V and a good cycle life for 72 cycles with a fixed capacity of 500 m Ah g^(-1) at 0.1 A g^(-1).This study proposes a strategy to achieve a low charge overpotential by confining Li_(2)O_(2) growth in the mesoporous channels of cathodes.
基金supported by the National Natural Science Foundation of China(Nos.22125903 and 51872283)Dalian Innovation Support Plan for High Level Talents(No.2019RT09)+2 种基金Dalian National Laboratory for Clean Energy(DNL),CAS,DNL Cooperation Fund,CAS(Nos.DNL201912,DNL201915,DNL202016,and DNL202019)DICP(No.DICP I2020032)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Nos.YLU‐DNL Fund 2021002 and YLU‐DNL 2021009).
文摘The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathode catalysts with high activity and stability is crucial to overcome the terrible issues at high current density.Herein,we report a surface engineering strategy to adjust the surface electron structure of boron(B)‐doped PtNi nanoalloy on carbon nanotubes(PtNiB@CNTs)as an efficient bifunctional cathodic catalyst for high‐rate and long‐life Li‐O2 batteries.Notably,the Li‐O2 batteries assembled with as‐prepared PtNiB@CNT catalyst exhibit ultrahigh discharge capacity of 20510 mA·h/g and extremely low overpotential of 0.48 V at a high current density of 1000 mA/g,both of which outperform the most reported Pt‐based catalysts recently.Meanwhile,our Li‐O2 batteries offer excellent rate capability and ultra‐long cycling life of up to 210 cycles at 1000 mA/g under a fixed capacity of 1000 mA·h/g,which is two times longer than those of Pt@CNTs and PtNi@CNTs.Furthermore,it is revealed that surface engineering of PtNi nanoalloy via B doping can efficiently tailor the electron structure of nanoalloy and optimize the adsorption of oxygen species,consequently delivering excellent Li‐O2 battery performance.Therefore,this strategy of regulating the nanoalloy by doping nonmetallic elements will pave an avenue for the design of high‐performance catalysts for metal‐oxygen batteries.
基金the National Key Research and Development Program of China(No.2019YFA0210004)the National Natural Science Foundation of China(Nos.22125503,21975242,U2032212,and 21890754)+5 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000)Youth Innovation Promotion Association of CAS(No.CX2340007003)the Key Research Program of Frontier Sciences of CAS(No.QYZDY-SSW-SLH011)the Major Program of Development Foundation of Hefei Center for Physical Science and Technology(No.2020HSC-CIP003)Users with Excellence Program of Hefei Science Center CAS(No.2020HSC-UE001)the University Synergy Innovation Program of Anhui Province(No.GXXT-2020-001)。
文摘CO_(2)electroreduction to formate is technically feasible and economically viable,but still suffers from low selectivity and high overpotential at industrial current densities.Here,lattice-distorted metallic nanosheets with disorder-engineered metal sites are designed for industrial-current-density CO_(2)-to-formate conversion at low overpotentials.As a prototype,richly lattice-distorted bismuth nanosheets are first constructed,where abundant disorder-engineered Bi sites could be observed by high-angle annular dark-field scanning transmission electron microscopy image.In-situ Fourier-transform infrared spectra reveal the CO_(2)•−*group is the key intermediate,while theoretical calculations suggest the electron-enriched Bi sites could effectively lower the CO_(2)activation energy barrier by stabilizing the CO_(2)•−*intermediate,further affirmed by the decreased formation energy from 0.49 to 0.39 eV.As a result,the richly lattice-distorted Bi nanosheets exhibit the ultrahigh current density of 800 mA·cm^(−2)with 91%Faradaic efficiencies for CO_(2)-to-formate electroreduction,and the formate selectivity can reach nearly 100%at the current density of 200 mA·cm^(−2)with a very low overpotential of ca.570 mV,outperforming most reported metal-based electrocatalysts.
基金supported by the National Natural Science Foundation of China(No.21725103)National Key R&D Program of China(No.2019YFA0705704)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA21010210)Jilin Province Science and Technology Development Plan Funding Project(No.20200201079JC)Changchun Science and Technology Development Plan Funding Project(No.19SS010)Jilin Province Capital Construction Funds Project(No.2020C026-1)the K.C.Wong Education Foundation(No.GJTD-2018-09).
文摘Electrochemical CO_(2) reduction reaction(CO_(2)RR)into value-added chemicals/fuels is crucial for realizing the sustainable carbon cycle while mitigating the energy crisis.However,it is impeded by the relatively high overpotential and low energy efficiency due to the lack of efficient electrocatalysts.Herein,we develop an isolated single-atom Ni catalyst regulated strategy to activate and stabilize the iron phthalocyanine molecule(Ni SA@FePc)toward a highly efficient CO_(2)RR process at low overpotential.The well-defined and homogenous catalytic centers with unique structures confer Ni SA@FePc with a significantly enhanced CO_(2)RR performance compared to single-atom Ni catalyst and FePc molecule and afford the atomic understanding on active sites and catalytic mechanism.As expected,Ni SA@FePc exhibits a high selectivity of more significant Faraday efficiency(≥95%)over a wide potential range,a high current density of~252 mA·cm^(−2) at low overpotential(390 mV),and excellent long-term stability for CO_(2)RR to CO.X-ray absorption spectroscopy measurement and theoretical calculation indicate the formation of NiN_(4)-O_(2)-FePc heterogeneous structure for Ni SA@FePc.And CO_(2)RR prefers to occur at the raised N centers of NiN4-O_(2)-FePc heterogeneous structure for Ni SA@FePc,which enables facilitated adsorption of*COOH and desorption of CO,and thus accelerated overall reaction kinetics.
基金supported by the National Natural Science Foundation of China(grant nos.51525805,51727812,and 51808526).
文摘The pH gradient caused by H^(+)/OH^(−)transport on an electrode surface is the key factor determining reaction performance,but its detailed impact on the electrode reaction kinetics has yet to be clarified.Here,the pH gradient effect was determined by developing electrode reaction equations,considering the overpotential assigned to the pH gradient called pH overpotential.The pH gradient effect was revealed to involve two aspects:(1)the Nernst pH overpotential,accounting for the common Nernst relationship with pH,and(2)the pH-dependent function of the electron-transfer coefficient(α_(pH)).Both parts were verified experimentally using oxygen reduction reaction and hydrogen evolution reaction,obviously,with differentα_(pH) functions.Detailedα_(pH) function effect was clarified based on numerical calculations of the electrode reaction equations.We found that the effect could be assessed suitably by an apparent constant(α_(app))and a nonlinear fitting method proposed forα_(app) value estimation.The results of this study provide the kinetic fundamentals of electrode reactions involving H^(+)/OH^(−)and contribute to the understanding and assessment of their performance with the H^(+)/OH^(−)transport effect.
基金supported by the National Natural Science Foundation of China(NSFC,22172121)the Natural Science Foundation of Sichuan Province(NSFSC,2023NSFSC1076)+1 种基金the Young Talent Project of State Ethnic Affairs Commissionthe Fundamental Research Funds for the Central Universities(ZYN2023106),Southwest Minzu University。
文摘Since low overpotential for the anodic ethanol oxidation reaction(EOR)can favor the higher output voltage and power of direct ethanol fuel cells(DEFCs),it is critical to design new EOR catalysts with efficient ethanol-to-CO_(2)activity at low applied potentials.Thereby,carbon-supported Ir-Bi_(2)O_(3)(Ir-Bi_(2)O_(3)/C)catalysts with highly dispersive bismuth oxide on the iridium surface are designed and prepared,which can merit splitting the ethanol C–C bond and promoting the oxidation of C1 intermediates at the bifunctional interfaces.The as-obtained Ir-Bi2O3/C catalysts show superior EOR mass activity of up to ca.2250 m A mgIr-1.Moreover,they exhibit the record lowest onset oxidation potentials(0.17–0.22 V vs.RHE)and the peak potential(ca.0.58 V vs.RHE),being 130–300 m V lower than the previous landmark noble metallic catalysts.Furthermore,an apparent C1 pathway faraday efficiency(FEC1)of 28%±5.9%at 0.5 V vs.RHE can be obtained at Ir-Bi_(2)O_(3)/C.This work might provide new insights into the new anodic EOR catalysts for increasing the power of DEFCs.
基金financially supported in China by the National Natural Science Foundation of China(21103224 and 21878227)Natural Science Funds for Distinguished Young Scholar of Heilongjiang Province(No.JC2018004)+2 种基金Natural Science Foundation of Hebei Province of China(B2019202210)in USA by NSF-CREST Center for Innovation,Research and Education in Environmental Nanotechnology(CIRE2N)(Grant Number HRD-1736093)supported by the Supercomputing Center in Harbin Normal University and Lvliang。
文摘Electrocatalytic nitrogen reduction reaction(NRR)at ambient conditions holds great promise for sustainably synthesizing ammonia(NH3),while developing highly-efficient,long-term stable,and inexpensive catalysts to activate the inert N≡N bond is a key scientific issue.In this work,on the basis of the concept"N-heterocyclic carbenes(NHCs)",we propose a carbon decorated graphitic-carbon nitride(C/g-C3N4)as novel metal-free NRR electrocatalyst by means of density functional theory(DFT)computations.Our results reveal that the introduced C atom in g-C3N4 surface can be regarded as NHCs and catalytic sites for activating N≡N bond,and are stabilized by the g-C3N4 substrate due to sterically disfavored dimerization.Especially,this NHCs-based heterogeneous catalysis can efficiently reduce the activated N2 molecule to NH3 with a low overpotential of 0.05 V via an enzymatic mechanism.Our work is the first report of NHCs-based electrocatalyst for N2 fixation,thus opening an alternative avenue for advancing sustainable NH3 production.
基金the National Natural Science Foundation of China(No.51874361)the National Natural Science Foundation of China Youth Fund(51904343)for supporting this work.
文摘In this study,commercial copper(Cu)foil and Cu foam are used as the working electrodes to systematically investigate the electrochemical deposition and dissolution processes of metallic lithium(Li)on these electrodes;Li metal deposited on the Cu foil electrode is porous and loose.The surface solid electrolyte interface(SEI)film after dissolution from Li dendrites maintains a dendritic porous structure,resulting in a large volume effect of the electrode during the cycle.The Cu foam electrode provides preferential nucleation and deposition sites near the side surface of the separator;the difference in Li affinity results in a heterogeneous deposition and dendrite growth of metallic Li.
基金supported by the National Research Foundation of Korea(NRF)–Grants funded by the Ministry of Science,ICT and Future Planning(2014R1A2A2A01004352),Republic of Korea
文摘The design of cost-effective, highly active catalysts for hydrogen energy production is a vital element in the societal pursuit of sustainable energy. Water electrolysis is one of the most convenient processes to produce high purity hydrogen. Cobalt-based catalysts are well-known electrocatalysts for oxygen evolution reaction(OER). In this article, all these merits indicate that the present cobalt nanocomposite is a promising electrocatalyst for OER. C–CoO-nanorods catalyst with nanorod structure was synthesized by hydrothermal treatment of CoCl·6HO/dextrose/urea mixture at 180 °C for 18 h and then calcined at400 °C for 3.5 h. The role of dextrose percentage in solution to achieve the uniform coating of carbon on the surface of CoO-nanorods has been demonstrated. The prepared materials were characterized by X-ray diffraction(XRD), X-ray photoelectron spectrum(XPS), field emission scanning electron microscopy(FE-SEM), high-resolution transmission electron microscopy(HR-TEM), and Brunauer–Emmett–Teller instrument(BET). Due to its unique morphology, the C–CoO-nanorods catalyst exhibited better activity than CoO-microplates catalyst for OER in 1 M KOH aqueous solution. The results showed a highly efficient, scalable, and low-cost method for developing highly active and stable OER electrocatalysts in alkaline solution.
基金supported by Research Grant Council (RGC) of Hong Kong (PolyU 5238/11E)
文摘In co-ionic conducting solid oxide fuel cell (SOFC), both oxygen ion (O2) and proton (H+) can transport through the electrolyte, generating steam in both the an-ode and cathode. Thus the mass transport phenomenon in the electrodes is quite different from that in conventional SOFC with oxygen ion conducting electrolyte (O-SOFC) or with proton conducting electrolyte (H-SOFC). The generation of steam in both electrodes also affects the concentration over-potential loss and further the SOFC performance. However, no detailed modeling study on SOFCs with co-ionic electrolyte has been reported yet. In this paper, a new mathematical model for SOFC based on co-ionic electrolyte was developed to predict its actual performance considering three major kinds of overpotentials. Ohm's law and the Butler-Volmer formula were used to model the ion conduction and electrochemical reactions, respectively. The dusty gas model (DGM) was employed to simulate the mass transport processes in the porous electrodes. Parametric simulations were performed to investigate the effects of proton transfer number (tH) and current density (jtotal) on the cell performance. It is interesting to find that the co-ionic conducting SOFC could perform better than O-SOFC and H-SOFC by choosing an appropriate proton transfer number. In addition, the co-ionic SOFC shows smaller difference between the anode and cathode concentration overpotentials than O-SOFC and H-SOFC at certain t H values. The results could help material selection for enhancing SOFC performance.
基金supported by the National Natural Science Foundation of China(21522602, 51672082, 91534202)the International Science and Technology Cooperation Program of China (2015DFA51220)+2 种基金the Research Project of Chinese Ministry of Education(113026A)the Program for Shanghai Youth Top-notch Talentthe Fundamental Research Funds for the Central Universities
文摘Searching for efficient and robust non-noble electrocatalysts for hydrogen generation is extremely desirable for future green energy systems.Here, we present the synthesis of integrated Ni-P-S nanosheets array including Ni_2P and NiS on nickel foam by a simple simultaneous phosphorization and sulfurization strategy. The resultant sample with optimal composition exhibits superior electrocatalytic performance for hydrogen evolution reaction(HER) in a wide pH range. In alkaline media, it can generate current densities of 10, 20 and 100 mA cm^(-2) at low overpotentials of only-101.9,-142.0 and-207.8 mV with robust durability. It still exhibits high electrocatalytic activities even in acid or neutral media. Such superior electrocatalytic performances can be mainly attributed to the synergistic enhancement of the hybrid Ni-P-S nanosheets array with integration microstructure. The kind of catalyst gives a new insight on achieving efficient and robust hydrogen generation.
基金Project(2003CB214501) supported by the National Basic Research Program of ChinaProject(48010) supported by the Excellent Doctor’s Science and Technology Innovation Foundation of Beijing Jiaotong Univsersity,China
文摘The iron-doped nickel oxide films used as oxygen evolution catalysts in the photoelectrochemical production of hydrogen from solar energy were deposited by means of RF reactive magnetron sputtering from a Ni-Fe alloy target in oxygen and argon atmosphere.The effects of processing parameters on the film properties,such as overpotential,composition,surface morphology and preferred orientation,were investigated.The electrochemical experiment,structural and compositional measurements indicate that the relative lower substrate temperature,higher RF power,higher working pressure and oxygen content are necessary to gain lower overpotential.The lowest overpotential of 251 mV is obtained at a current density of 80 mA/cm2.The existence of iron,which acts as activity site,and Ni3+ ion is responsible for lowering overpotential.By analyzing SEM and XRD data,it is also noticed that an improvement in crystallinity,appropriate grain size and less crystalline phase contribute to an increased electrocatalytic activity in oxygen evolution reaction.These results mentioned above indicate that iron-doped nickel oxide is promising as an oxygen catalyst.
基金financial support from the National Natural Science Foundation of China(21878202,21975175)the Natural Science Foundation of Shanxi Province(201801D121052)。
文摘Metal-organic frameworks(MOFs)exhibit excellent application potential in the field of electrocatalysis.In this study,we first prepare MIL-100 nanosheets on nickel foam(MIL-100/NF)and then successfully anchor Ag nanoparticles(NPs)on the nanosheets(Ag@MIL-100/NF)for oxygen evolution reaction(OER)catalysis.This strategy dramatically improves the conductivity of MIL-100 and the Ag NPs are uniformly dispersed on the nanosheets.The Ag@MIL-100/NF catalyst has excellent electrocatalytic performance and long-term corrosion resistance,with a low overpotential of 207 mV and a long-term stability of at least 100 h at a current density of 50 mA·cm^(-2).The experimental results demonstrate that this high OER catalytic performance is due to the improved charge transfer after loading Ag NPs,the combination of nanosheets and highly dispersed Ag NPs that expose more active sites and the adjusted chemical valence states of Fe and Ni in MIL-100.This work provides a surface decoration approach for the preparation of excellent catalysts directly used in the OER.
基金supported by the National Natural Science Foundation of China (21825106, 92061201)the Program for Innovative Research Team (in Science and Technology) in Universities of Henan Province (19IRTSTHN022)Zhengzhou University。
文摘The society’s urgent demand for environmentally friendly, safe and low-cost energy storage devices has promoted the research of aqueous zinc-ion batteries. However, the uneven deposition of Zn ions on anodes will lead to the growth of the dendrite and reduce the Coulombic efficiency as well as the lifespan of the devices. Herein, we construct an O,N-dual functionalized carbon cloth current collector via a simple hydrothermal strategy, in which the oxygen-containing functional groups and the N heteroatoms can regulate the transmission and deposition of Zn ions, respectively. The proposed synergistic strategy ensures the uniform distribution of Zn ions on the surface of the Zn anode and inhibits the formation of dendrites. The symmetric cell based on the O,N-dual doped carbon cloth presents superior cycling stability(318 h) with a low voltage hysteresis(11.2 mV) at an areal capacity of 1 m Ah cm^(-2)(20% depth of diacharge). Meanwhile, the appreciably low overpotential(16 m V) and high Columbic efficiency(98.2%)also demonstrate that the O,N-dual functionalized carbon cloth can be worked as a promising host for Zn ions deposition.
文摘Nickel-metal hydride (Ni/MH) batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-temperature-efficiency of nickel electrode, spherical nickel hydroxide mixed with various ratios of Lu2O3 was used as active material of pasted nickel electrodes. The results of charge/discharge experiments, cyclic voltammetric measurements and XRD characterizations have shown that after addition of Lu2O3, the oxygen evolution overpotcntial is elevated much, the charge efficiency of nickel electrode at high temperature is greatly improved and the content of β-NiOOH phase increases in charged electrodes. In addition, the mixed ratio of Lu2O3 has different effects on high temperature performances of nickel electrode at different charge/discharge currents, 3.5 % is the optimum mixed ratio, and the action of Lu2O3 on high temperature electrochemical behaviors is more apparent when nickel electrodes are charged at small current than large current.
基金China Postdoctoral Science Foundation,Grant/Award Number:2019M661825Natural Science Foundation of Jiangsu Province,Grant/Award Numbers:BK20190413,BK20210616Japan Society。
文摘Aprotic lithium–oxygen batteries(LOBs)have been recognized as novel energy storage devices for their outstanding specific energy density,while the large discharge/charge overpotential is a tough barrier to be overcome.Here,hetero-structured MoS_(2)/ZnIn_(2)S_(4) nanosheets have been prepared to capture visible light and the generated charge carriers are utilized for promoting both the oxygen reduction reaction and the oxygen evolution reaction.With the light illumination in the discharge process,the abundant photo-inspired electrons serve as the reaction sites to promote the reduction of O_(2) into LiO_(2) which is finally deposited as Li_(2)O_(2).On the contrary,the generated holes in the valence band can contribute to the low oxidization potential of Li_(2)O_(2) during the charge process.It delivers a low charge potential of 3.29 V,with an excellent resulting energy efficiency of 96.7%,much superior to that of 69.2%in the dark condition.It is noted that the involvement of photoelectrons has influenced the growth of Li_(2)O_(2) films on the MoS_(2)/ZnIn_(2)S_(4) nanosheets through the surface-adsorption pathway.The insights from the theoretical calculation confirm that the photoelectrons favor the absorption of LiO_(2) and the formation of the Li_(2)O_(2) film through the surface route.Therefore,this paper provides a deeper understanding of the mechanism of photoinspired charge carriers in LOBs and will enable further exploration of photo-involved energy storage systems.
基金financial support from an Australian Research Council(ARC)Discovery Project(DP180101453)The Distinguished Young Scientists Program of the National Natural Science Foundation of China(No.51425301)+1 种基金the National Natural Science Foundation of China(No.52002171,No.52002050)the Natural Science Foundation of Jiangsu Province(No.BK20200696,No.BK20200768,No.20KJB430019)are greatly appreciated
文摘A facile synthesis of Ag nanocrystals encapsulated in nitrogen-doped carbon fiber(NCF)is proposed,based on the simultaneous reaction between pyrrole and Ag^(+)ions in an aqueous solvent followed by a heat treatment.The as-prepared Ag/NCF demonstrated superior catalytic behavior toward ORR and OER.Besides improved cycling stability,a much lower discharge/charge gap of 0.89 V(vs Li/Li^(+))compared with 1.38 V for NCF cathode with a fixed capacity of 500 m Ah g^(-1)was obtained in lithium oxygen batteries.The introduction of Ag crystals into NCF facilitates the oxygen reduction reaction/oxygen evolution reaction kinetics.X-ray diffraction analysis coupled with Raman spectroscopy confirmed that Ag/NCF cathode could reversibly catalyze Li_(2)O_(2)formation and decomposition.The NCF matrix offers a conductive network to realize rapid mass transfer and the encapsulated Ag nanocrystals supplied effective catalytic active sites.The combined action between both contributes to the superior electrocatalytic performance.