High performance of lithium-sulfur batteries have been dragged down by their shuttling behavior which is complicated multiphase transition-based 16-electron redox reactions of the S8/Li2 S.In this article,the triple-p...High performance of lithium-sulfur batteries have been dragged down by their shuttling behavior which is complicated multiphase transition-based 16-electron redox reactions of the S8/Li2 S.In this article,the triple-phase interfaces of graphene-like carbon clusters on antimony trisulfide(C-Sb_(2)S_(3))nanowires are tailored to design a multifunctional polysulfide host which can inhibit migration of polysulfides and accelerate conversion kinetics of redox electrochemical reactions.Benefiting from the triple-interface design of polysulfides/Sb_(2)S_(3)/carbon clusters,the C-Sb_(2)S_(3) electrode not only anchors polysulfide migration by the synergistic effect of Sb,S,and C atoms as interfacial active sites,but also the graphene-like carbon clusters shorten the diffusion paths to further favor redox electron/ion transport through the liquid(electrolyte/polysulfide)and solid(Li2 S/S8,carbon clusters,and Sb_(2)S_(3))-based triple-phases.Therefore,these Li_(2)S_(6)-based C-Sb_(2)S_(3) cells possess high sulfur loading,excellent cycling stability,impressive specific capacity,and great rate capability.This work of interfacial engineering reveals insight for powering reaction kinetics in the complicated multistep catalysis reaction with multiphase evolution-based chargetransfer/non-transfer processes.展开更多
The efficiency of photocatalytic CO_(2) reduction reaction(PCRR)is restricted by the low solubility and mobility of CO_(2) in water,poor CO_(2) adsorption capacity of catalyst,and competition with hydrogen evolution r...The efficiency of photocatalytic CO_(2) reduction reaction(PCRR)is restricted by the low solubility and mobility of CO_(2) in water,poor CO_(2) adsorption capacity of catalyst,and competition with hydrogen evolution reaction(HER).Recently,hydrophobic modification of the catalyst surface has been proposed as a potential solution to induce the formation of triple-phase contact points(TPCPs)of CO_(2)(gas phase),H_(2) O(liquid phase),and catalysts(solid phase)near the surface of the catalyst,enabling direct delivery of highly concentrated CO_(2) molecules to the active reaction sites,resulting in higher CO_(2) and lower H+surface concentrations.The TPCPs thus act as the ideal reaction points with enhanced PCRR and suppressed HER.However,the initial synthesis of triple-phase photocatalysts tends to possess a lower bulk density of TPCPs due to the simple structure leading to limited active points and CO_(2) adsorption sites.Here,based on constructing a hydrophobic hierarchical porous TiO_(2)(o-HPT)with interconnected macropores and mesopores structure,we have significantly increased the density of TPCPs in a unit volume of the photocatalyst.Compared with hydrophobic macroporous TiO_(2)(o-MacPT)or mesoporous TiO_(2)(o-MesPT),the o-HPT with increased TPCP density leads to enhanced photoactivity,enabling a high methanol production rate with 1111.5μmol g^(−1) h^(−1) from PCRR.These results emphasize the significance of high-density TPCPs design and propose a potential path for developing efficient PCRR systems.展开更多
The objective of this study was to provide the characteristics of hepatic computed tomography images and optimize their transition delay with a bolus-tracking technique for triple-phase hepatic computed tomography in ...The objective of this study was to provide the characteristics of hepatic computed tomography images and optimize their transition delay with a bolus-tracking technique for triple-phase hepatic computed tomography in cats.Dynamic triple-phase computed tomography was performed in nine healthy cats.The upper third of the liver was dynamically scanned every 0.5 s for 40 s.The time density curves of the aorta and hepatic parenchyma mean enhancement were analyzed.Triple-phase hepatic computed tomography was performed three times with a bolus trigger of 200 Hounsfield units of aortic enhancement.The transition delays of the arterial,portal,and hepatic parenchymal phases were respectively 0,5 and 60 s in the first scan;2,7 and 62 s in the second scan;and 4,9 and 64 s in the third scan.All computed tomography images were evaluated by a certificated radiologist.The arterial vessels and their main branches were well enhanced at a 2 s transition delay.The contrast of the portal vein to the liver parenchyma was most obvious at a 7 s transition delay.The mean enhancement of the hepatic parenchyma peaked at a 62 s transition delay,whereas the degree of enhancement of the hepatic vasculature decreased.In this study,the recommended transition delays for the arterial,portal,and hepatic parenchymal phases were 2 s,7 s and 62 s,respectively,after triggering at 200 Hounsfield units of aortic enhancement.This information may be helpful in diagnosing feline liver diseases and provides a key reference for the clinical implementation of CT.展开更多
The point-to-point contact mechanism in all-solid-state Li-S batteries(ASSLSBs)is not as efficient as a liquid electrolyte which has superior mobility in the electrode,resulting in a slower reaction kinetics and inade...The point-to-point contact mechanism in all-solid-state Li-S batteries(ASSLSBs)is not as efficient as a liquid electrolyte which has superior mobility in the electrode,resulting in a slower reaction kinetics and inadequate ionic/electronic conduction network between the S(or Li_(2)S),conductive carbon,and solid-state electrolytes(SSEs)for achieving a swift(dis)charge reaction.Herein,a series of hybrid ionic/electronic conduction triple-phase interfaces with transition metal and nitrogen co-doping were designed.The graphitic ordered mesoporous carbon frameworks(TM-N-OMCs;TM=Fe,Co,Ni,and Cu)serve as hosts for Li_(2)S and Li_(6)PS_(5)Cl(LPSC)and provide abundant reaction sites on the triple interface.Results from both experimental and computational research display that the combination of Cu-N co-dopants can promote the Li-ion diffusion for rapid transformation of Li_(2)S with adequate ionic(6.73×10^(−4)S·cm^(−1))/electronic conductivities(1.77×10^(−2)S·cm^(−1))at 25℃.The as-acquired Li_(2)S/Cu-N-OMC/LPSC electrode exhibits a high reversible capacity(1147.7 mAh·g^(−1))at 0.1 C,excellent capacity retention(99.5%)after 500 cycles at 0.5 C,and high areal capacity(7.08 mAh·cm^(−2)).展开更多
Lithium-sulfur batteries with liquid electrolytes have been obstructed by severe shuttle effects and intrinsic safety concerns.Introducing inorganic solid-state electrolytes into lithium-sulfur systems is believed as ...Lithium-sulfur batteries with liquid electrolytes have been obstructed by severe shuttle effects and intrinsic safety concerns.Introducing inorganic solid-state electrolytes into lithium-sulfur systems is believed as an effective approach to eliminate these issues without sacrificing the high-energy density,which determines sulfidebased all-solid-state lithium-sulfur batteries.However,the lack of design principles for high-performance composite sulfur cathodes limits their further application.The sulfur cathode regulation should take several factors including the intrinsic insulation of sulfur,well-designed conductive networks,integrated sulfur-electrolyte interfaces,and porous structure for volume expansion,and the correlation between these factors into account.Here,we summarize the challenges of regulating composite sulfur cathodes with respect to ionic/electronic diffusions and put forward the corresponding solutions for obtaining stable positive electrodes.In the last section,we also outlook the future research pathways of architecture sulfur cathode to guide the develop high-performance all-solid-state lithium-sulfur batteries.展开更多
In the present study,two Ni/YSZ anodes with different volume ratios of Ni and YSZ,30:70 and 45:55 vol%,are operated in dry methane under open circuit and polarized conditions.Three-dimensional(3D)Ni/YSZ microstructure...In the present study,two Ni/YSZ anodes with different volume ratios of Ni and YSZ,30:70 and 45:55 vol%,are operated in dry methane under open circuit and polarized conditions.Three-dimensional(3D)Ni/YSZ microstructures after carbon deposition are reconstructed by the focused ion beam-scanning electron microscopy(FIB-SEM)with the help of machine learning segmentation.From the reconstructed mircostructures,volume fraction,connectivity,three phase boundary(TPB)density,and tortuosity are quantified.In addition,local carbon microstructures are quantitatively reconstructed,and the effect of polarization on carbon morphology is investigated.It is demonstrated that Ni surface in the vicinity of active TPB near the electrolyte is free from carbon formation,while remaining Ni surface at some distances from TPB exhibits severe carbon deposition.In average,total amount of carbon deposition is larger near the electrolyte.These observations imply complex interplay between the electrochemical steam generation and methane cracking on Ni surface which take place very locally near the active TPB.展开更多
Proton exchange membrane water electrolysis(PEMWE)plays a critical role in practical hydrogen production.Except for the electrode activities,the widespread deployment of PEMWE is severely obstructed by the poor electr...Proton exchange membrane water electrolysis(PEMWE)plays a critical role in practical hydrogen production.Except for the electrode activities,the widespread deployment of PEMWE is severely obstructed by the poor electron-proton permeability across the catalyst layer(CL)and the inefficient transport structure.In this work,the PEDOT:F(Poly(3,4-ethylenedioxythiophene):perfluorosulfonic acid)ionomers with mixed proton-electron conductor(MPEC)were fabricated,which allows for a homogeneous anodic CL structure and the construction of a highly efficient triple-phase interface.The PEDOT:F exhibits strong perfluorosulfonic acid(PFSA)side chain extensibility,enabling the formation of large hydrophilic ion clusters that form proton-electron transport channels within the CL networks,thus contributing to the surface reactant water adsorption.The PEMWE device employing membrane electrode assembly(MEA)prepared by PEDOT:F-2 demonstrates a competitive voltage of 1.713 V under a water-splitting current of 2 A cm^(-2)(1.746 V at 2A cm^(-2) for MEA prepared by Nafion D520),along with exceptional long-term stability.Meanwhile,the MEA prepared by PEDOT:F-2 also exhibits lower ohmic resistance,which is reduced by 23.4%and 17.6%at 0.1 A cm^(-2) and 1.5 A cm^(-2),respectively,as compared to the MEA prepared by D520.The augmentation can be ascribed to the superior proton and electron conductivity inherent in PEDOT:F,coupled with its remarkable structural stability.This characteristic enables expeditious mass transfer during electrolytic reactions,thereby enhancing the performance of PEMWE devices.展开更多
Optimizing the architecture of air electrodes is pivotal for improving reaction kinetics and structural stability in zinc-air batteries(ZABs),yet balancing these enhancements with cost-effective fabrication remains a ...Optimizing the architecture of air electrodes is pivotal for improving reaction kinetics and structural stability in zinc-air batteries(ZABs),yet balancing these enhancements with cost-effective fabrication remains a challenge.Herein,a facile biomimetic assembly strategy is proposed to construct an asymmetric air electrode with Janus carbonaceous architecture and wettability gradient.Two components,which are functionalized graphene nanosheets(FGNSs)and carbon nanotubes(FCNTs)both anchoring iron phthalocyanine for oxygen reduction catalysis,are employed as building blocks.The former assemble into fish-scale-like hydrophilic lamellar structure facing the electrolyte,facilitating swift ion infiltration;while the latter arrange into waterspider-leg-like hydrophobic villus structure exposed to ambient air,enhancing rapid oxygen invasion.This asymmetric design(Asy-FCNTs-FGNSs)not only boosts mass transport and expands triple-phase boundary,but also improves structural robustness of the air electrode.The resulting ZAB achieves a high peak power density of 239.3 mW cm^(−2)and a specific capacity of 814.3 mAh g_(Zn)^(−1)(10 mA cm^(−2)),along with outstanding cycling stability,overwhelmingly outperforming conventional symmetric counterparts and prior self-supporting designs.This work presents an innovative architecture-optimization scheme for advanced air electrodes,offering a scalable bioinspired strategy to propel ZAB technology and guide future electrode advancements.展开更多
Membra ne electrode assemblies(MEAs)are pivotal to advancing proton exchange membra ne water electrolysis(PEMWE),yet conventional designs suffer from limited triple-phase boundaries(TPBs),inefficient mass/charge trans...Membra ne electrode assemblies(MEAs)are pivotal to advancing proton exchange membra ne water electrolysis(PEMWE),yet conventional designs suffer from limited triple-phase boundaries(TPBs),inefficient mass/charge transport,and insufficient durability.This study introduces a three-dimensional ordered pattern-array(3D OPA)architecture fabricated via a scalable laser-machined mask and hot-pressing strategy.The 3D OPA MEA achieves a current density of 3.73 A cm^(-2) at 2 V,demonstrating a 50%performance improvement over the conventional MEA(2.48 A cm^(-2)),alongside a degradation rate of 26.6μV h^(-1) in a highly dynamic accelerated stress test(AST).Additionally,numerical simulations corroborate that the OPA architecture optimizes localized oxygen diffusion and liquid water replenishment,enhancing reaction kinetics.The 3D OPA architecture enhances TPBs and establishes optimized gas-liquid tra nsport pathways,significantly improving catalyst utilization while minimizing mass transfer overpotential and bubble-induced losses.Furthermore,its interlocking design reinforces mechanical interactions,reducing ohmic resistance a nd ensuring sustained mecha nical integrity and electrochemical durability.This work provides a simple,cost-effective,and scalable approach for patterned MEAs,addressing critical barriers to PEMWE commercialization through rational TPB engineering and transport pathway optimization.展开更多
Hydrogels and aerogels,with their self-supporting nature and highly porous structures,have emerged as promising electrode materials for energy conversion devices such as fuel cells,batteries,and electrolyzers.Their hi...Hydrogels and aerogels,with their self-supporting nature and highly porous structures,have emerged as promising electrode materials for energy conversion devices such as fuel cells,batteries,and electrolyzers.Their hierarchical porosity,extended active surface area,and enhanced ion and mass transport properties make them attractive for electrochemical applications.However,achieving an efficient three-phase reaction interface within these 3-dimensional(3D)structures remains a key challenge,as it directly impacts catalytic activity and overall device performance.Recent advancements have focused on tailoring gel properties to optimize electrochemical performance,bridging material synthesis,structural engineering,and device integration to enhance reaction kinetics,durability,and scalability.A deeper understanding of the relationships between gel composition,porosity,surface properties,and electrochemical behavior is essential for developing next-generation energy devices.This review provides a comprehensive analysis of hydrogel-and aerogel-based electrodes,covering their design principles,fabrication strategies,and electrochemical applications.By examining recent progress and key challenges,we offer insights into the bottom-up development of advanced 3D electrodes,aiming to accelerate the practical implementation of gel-based materials in sustainable energy conversion.展开更多
Precious metal-free electrocatalysts often require significantly more loadings to achieve similar performance as Pt does in fuel cells and metal air batteries.The high loadings cause substantial mass transportation re...Precious metal-free electrocatalysts often require significantly more loadings to achieve similar performance as Pt does in fuel cells and metal air batteries.The high loadings cause substantial mass transportation resistance.To address this challenge,we synthesized ordered mesoporous carbon nanofiber electrocatalyst that enables unimpeded mass transfer at mesoscale.The synthesis was based on electrospinning of supramolecular micelles,which were stretched under hydrodynamic forces and self-assembled as in oriented and ordered form.Ordered mesoporous carbon nanofibers(OMCNFs)were obtained after removing the micelle template.The aligned mesopores over electrode scale strongly accelerate diffusion kinetics.The OH−ion diffusion coefficient of OMCNF is 26 times larger than that of the nanofiber with non-ordered pores(NMCNF)and 206 times larger than that of Pt/C.As a result,the electrocatalytic performance of OMCNF was maintained at increased catalyst loadings,while performance deterioration was observed in NMCNF and Pt/C.The assembled zinc-air batteries using aqueous electrolyte and solid-state electrolyte delivered high power density and nice cycling performance.展开更多
Gas-involving electrochemical reactions,like oxygen reduction reaction (ORR),oxygen evolution reaction (OER),and hydrogen evolution reaction (HER),are critical processes for energy-saving,environment-friendly energy c...Gas-involving electrochemical reactions,like oxygen reduction reaction (ORR),oxygen evolution reaction (OER),and hydrogen evolution reaction (HER),are critical processes for energy-saving,environment-friendly energy conversion and storage technologies which gain increasing attention.The development of according electrocatalysts is key to boost their electrocatalytic performances.Dramatic efforts have been put into the development of advanced electrocatalysts to overcome sluggish kinetics.On the other hand,the electrode interfaces-architecture construction plays an equally important role for practical applications because these imperative electrode reactions generally proceed at triple-phase interfaces of gas,liquid electrolyte,and solid electrocatalyst.A desirable architecture should facilitate the complicate reactions occur at the triple-phase interfaces,which including mass diffusion,surface reaction and electron transfer.In this review,we will summarize some design principles and synthetic strategies for optimizing triple-phase interfaces of gas-involving electrocatalysis systematically,based on the electrode reaction process at the three-phase interfaces.It can be divided into three main optimization directions:exposure of active sites,promotion of mass diffusion and acceleration of electron transfer.Furthermore,we especially highlight several remarkable works with comprehensive optimization about specific energy conversion devices,including metal-air batteries,fuel cells,and water-splitting devices are demonstrated with superb efficiency.In the last section,the perspectives and challenges in the future are proposed.展开更多
Low-platinum(Pt)alloy catalysts hold promising application in oxygen reduction reaction(ORR)electrocatalysis of protonexchange-membrane fuel cells(PEMFCs).Although significant progress has been made to boost the kinet...Low-platinum(Pt)alloy catalysts hold promising application in oxygen reduction reaction(ORR)electrocatalysis of protonexchange-membrane fuel cells(PEMFCs).Although significant progress has been made to boost the kinetic ORR mass activity at low current densities in liquid half-cells,little attention was paid to the performance of Pt-based catalysts in realistic PEMFCs particularly at high current densities for high power density,which remains poorly understood.In this paper,we show that,regardless of the kinetic mass activity at the low current density region,the high current density performance of the low-Pt alloy catalysts is dominantly controlled by the total Pt surface area,particularly in low-Pt-loading H_(2)–air PEMFCs.To this end,we propose two different strategies to boost the specific Pt surface area,the post-15-nm dealloyed nanoporous architecture and the sub-5-nm solid core–shell nanoparticles(NPs)through fluidic-bed synthesis,both of which bring in comparably high mass activity and high Pt surface area for large-current-density performance.At medium current density,the dealloyed porous NPs provide substantially higher H_(2)–air PEMFC performance compared to solid core–shell catalysts,despite their similar mass activity in liquid half-cells.Scanning transmission electron microscopy images combined with electron energy loss spectroscopic imaging evidence a previously unreported“semi-immersed nanoporous-Pt/ionomer”structure in contrast to a“fully-immersed core–shellPt/ionomer”structure,thus favoring O_(2) transport and improving the fuel cell performance.Our results provide new insights into the role of Pt nanostructures in concurrently optimizing the mass activity,Pt surface area and Pt/Nafion interface for high power density fuel cells.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61904080)the Natural Science Foundation of Jiangsu Province(Grant No.BK20190670)+1 种基金the Natural Science Foundation of Colleges and Universities in Jiangsu Province(Grant No.19KJB530008)the Technology Innovation Project for Overseas Scholar in Nanjing,the Start-up Foundation of Nanjing Tech University。
文摘High performance of lithium-sulfur batteries have been dragged down by their shuttling behavior which is complicated multiphase transition-based 16-electron redox reactions of the S8/Li2 S.In this article,the triple-phase interfaces of graphene-like carbon clusters on antimony trisulfide(C-Sb_(2)S_(3))nanowires are tailored to design a multifunctional polysulfide host which can inhibit migration of polysulfides and accelerate conversion kinetics of redox electrochemical reactions.Benefiting from the triple-interface design of polysulfides/Sb_(2)S_(3)/carbon clusters,the C-Sb_(2)S_(3) electrode not only anchors polysulfide migration by the synergistic effect of Sb,S,and C atoms as interfacial active sites,but also the graphene-like carbon clusters shorten the diffusion paths to further favor redox electron/ion transport through the liquid(electrolyte/polysulfide)and solid(Li2 S/S8,carbon clusters,and Sb_(2)S_(3))-based triple-phases.Therefore,these Li_(2)S_(6)-based C-Sb_(2)S_(3) cells possess high sulfur loading,excellent cycling stability,impressive specific capacity,and great rate capability.This work of interfacial engineering reveals insight for powering reaction kinetics in the complicated multistep catalysis reaction with multiphase evolution-based chargetransfer/non-transfer processes.
基金National Natural Science Foundation of China(Nos.22008121,11774173,51790492)the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(No.T2125004)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.30920032204,30920041115)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(No.2022-K12)Funding of NJUST(No.TSXK2022D002)for financial support.
文摘The efficiency of photocatalytic CO_(2) reduction reaction(PCRR)is restricted by the low solubility and mobility of CO_(2) in water,poor CO_(2) adsorption capacity of catalyst,and competition with hydrogen evolution reaction(HER).Recently,hydrophobic modification of the catalyst surface has been proposed as a potential solution to induce the formation of triple-phase contact points(TPCPs)of CO_(2)(gas phase),H_(2) O(liquid phase),and catalysts(solid phase)near the surface of the catalyst,enabling direct delivery of highly concentrated CO_(2) molecules to the active reaction sites,resulting in higher CO_(2) and lower H+surface concentrations.The TPCPs thus act as the ideal reaction points with enhanced PCRR and suppressed HER.However,the initial synthesis of triple-phase photocatalysts tends to possess a lower bulk density of TPCPs due to the simple structure leading to limited active points and CO_(2) adsorption sites.Here,based on constructing a hydrophobic hierarchical porous TiO_(2)(o-HPT)with interconnected macropores and mesopores structure,we have significantly increased the density of TPCPs in a unit volume of the photocatalyst.Compared with hydrophobic macroporous TiO_(2)(o-MacPT)or mesoporous TiO_(2)(o-MesPT),the o-HPT with increased TPCP density leads to enhanced photoactivity,enabling a high methanol production rate with 1111.5μmol g^(−1) h^(−1) from PCRR.These results emphasize the significance of high-density TPCPs design and propose a potential path for developing efficient PCRR systems.
基金This study was supported by the National Natural Science Foundation of China(Nos:31802255,31972756 and 32072938).
文摘The objective of this study was to provide the characteristics of hepatic computed tomography images and optimize their transition delay with a bolus-tracking technique for triple-phase hepatic computed tomography in cats.Dynamic triple-phase computed tomography was performed in nine healthy cats.The upper third of the liver was dynamically scanned every 0.5 s for 40 s.The time density curves of the aorta and hepatic parenchyma mean enhancement were analyzed.Triple-phase hepatic computed tomography was performed three times with a bolus trigger of 200 Hounsfield units of aortic enhancement.The transition delays of the arterial,portal,and hepatic parenchymal phases were respectively 0,5 and 60 s in the first scan;2,7 and 62 s in the second scan;and 4,9 and 64 s in the third scan.All computed tomography images were evaluated by a certificated radiologist.The arterial vessels and their main branches were well enhanced at a 2 s transition delay.The contrast of the portal vein to the liver parenchyma was most obvious at a 7 s transition delay.The mean enhancement of the hepatic parenchyma peaked at a 62 s transition delay,whereas the degree of enhancement of the hepatic vasculature decreased.In this study,the recommended transition delays for the arterial,portal,and hepatic parenchymal phases were 2 s,7 s and 62 s,respectively,after triggering at 200 Hounsfield units of aortic enhancement.This information may be helpful in diagnosing feline liver diseases and provides a key reference for the clinical implementation of CT.
基金supported by the National Natural Science Foundation of China(No.T2241003)the National Key Research and Development Program of China(No.2022YFB4003500)the Key R&D project of Hubei Province,China(No.2021AAA006).
文摘The point-to-point contact mechanism in all-solid-state Li-S batteries(ASSLSBs)is not as efficient as a liquid electrolyte which has superior mobility in the electrode,resulting in a slower reaction kinetics and inadequate ionic/electronic conduction network between the S(or Li_(2)S),conductive carbon,and solid-state electrolytes(SSEs)for achieving a swift(dis)charge reaction.Herein,a series of hybrid ionic/electronic conduction triple-phase interfaces with transition metal and nitrogen co-doping were designed.The graphitic ordered mesoporous carbon frameworks(TM-N-OMCs;TM=Fe,Co,Ni,and Cu)serve as hosts for Li_(2)S and Li_(6)PS_(5)Cl(LPSC)and provide abundant reaction sites on the triple interface.Results from both experimental and computational research display that the combination of Cu-N co-dopants can promote the Li-ion diffusion for rapid transformation of Li_(2)S with adequate ionic(6.73×10^(−4)S·cm^(−1))/electronic conductivities(1.77×10^(−2)S·cm^(−1))at 25℃.The as-acquired Li_(2)S/Cu-N-OMC/LPSC electrode exhibits a high reversible capacity(1147.7 mAh·g^(−1))at 0.1 C,excellent capacity retention(99.5%)after 500 cycles at 0.5 C,and high areal capacity(7.08 mAh·cm^(−2)).
基金supported by the National Natural Science Foundation of China(No.52272241)the start-up funding from Zhejiang University。
文摘Lithium-sulfur batteries with liquid electrolytes have been obstructed by severe shuttle effects and intrinsic safety concerns.Introducing inorganic solid-state electrolytes into lithium-sulfur systems is believed as an effective approach to eliminate these issues without sacrificing the high-energy density,which determines sulfidebased all-solid-state lithium-sulfur batteries.However,the lack of design principles for high-performance composite sulfur cathodes limits their further application.The sulfur cathode regulation should take several factors including the intrinsic insulation of sulfur,well-designed conductive networks,integrated sulfur-electrolyte interfaces,and porous structure for volume expansion,and the correlation between these factors into account.Here,we summarize the challenges of regulating composite sulfur cathodes with respect to ionic/electronic diffusions and put forward the corresponding solutions for obtaining stable positive electrodes.In the last section,we also outlook the future research pathways of architecture sulfur cathode to guide the develop high-performance all-solid-state lithium-sulfur batteries.
基金partly supported by the New Energy and Industrial Technology Development Organization(NEDO)by the Japan Society for the Promotion of Science KAKENHI(21K14090)+3 种基金the National Key R&D Program of China(2019YFE0122000)the Scientific Research Foundation of Graduate School of Southeast University(YBPY2106)the China Scholarship Councilby the Advanced Research Infrastructure for Materials and Nanotechnology in Japan(ARIM Japan)sponsored by the Ministry of Education,Culture,Sport,Science and Technology(MEXT),Japan。
文摘In the present study,two Ni/YSZ anodes with different volume ratios of Ni and YSZ,30:70 and 45:55 vol%,are operated in dry methane under open circuit and polarized conditions.Three-dimensional(3D)Ni/YSZ microstructures after carbon deposition are reconstructed by the focused ion beam-scanning electron microscopy(FIB-SEM)with the help of machine learning segmentation.From the reconstructed mircostructures,volume fraction,connectivity,three phase boundary(TPB)density,and tortuosity are quantified.In addition,local carbon microstructures are quantitatively reconstructed,and the effect of polarization on carbon morphology is investigated.It is demonstrated that Ni surface in the vicinity of active TPB near the electrolyte is free from carbon formation,while remaining Ni surface at some distances from TPB exhibits severe carbon deposition.In average,total amount of carbon deposition is larger near the electrolyte.These observations imply complex interplay between the electrochemical steam generation and methane cracking on Ni surface which take place very locally near the active TPB.
基金supported by the National Natural Science Foundation of China(52202009)Key Research and Development Program of Guangdong Province(2020B0909040001)+1 种基金Key R&D project of Hubei Province,China(2021AAA006)Guangdong Hydrogen Energy Institute of WHUT under Guangdong Key Areas Research and Development Program(2019B090909003).
文摘Proton exchange membrane water electrolysis(PEMWE)plays a critical role in practical hydrogen production.Except for the electrode activities,the widespread deployment of PEMWE is severely obstructed by the poor electron-proton permeability across the catalyst layer(CL)and the inefficient transport structure.In this work,the PEDOT:F(Poly(3,4-ethylenedioxythiophene):perfluorosulfonic acid)ionomers with mixed proton-electron conductor(MPEC)were fabricated,which allows for a homogeneous anodic CL structure and the construction of a highly efficient triple-phase interface.The PEDOT:F exhibits strong perfluorosulfonic acid(PFSA)side chain extensibility,enabling the formation of large hydrophilic ion clusters that form proton-electron transport channels within the CL networks,thus contributing to the surface reactant water adsorption.The PEMWE device employing membrane electrode assembly(MEA)prepared by PEDOT:F-2 demonstrates a competitive voltage of 1.713 V under a water-splitting current of 2 A cm^(-2)(1.746 V at 2A cm^(-2) for MEA prepared by Nafion D520),along with exceptional long-term stability.Meanwhile,the MEA prepared by PEDOT:F-2 also exhibits lower ohmic resistance,which is reduced by 23.4%and 17.6%at 0.1 A cm^(-2) and 1.5 A cm^(-2),respectively,as compared to the MEA prepared by D520.The augmentation can be ascribed to the superior proton and electron conductivity inherent in PEDOT:F,coupled with its remarkable structural stability.This characteristic enables expeditious mass transfer during electrolytic reactions,thereby enhancing the performance of PEMWE devices.
基金supported by the National Natural Science Foundation of China(22379056,22479065,92572201,and U25A20238)the Natural Science Foundation of Jiangsu Province(BK20231346)the Carbon Peak and Carbon Neutrality Project(Breakthrough for Industry Prospect and Key Technologies)of Zhenjiang City(CG2023003).
文摘Optimizing the architecture of air electrodes is pivotal for improving reaction kinetics and structural stability in zinc-air batteries(ZABs),yet balancing these enhancements with cost-effective fabrication remains a challenge.Herein,a facile biomimetic assembly strategy is proposed to construct an asymmetric air electrode with Janus carbonaceous architecture and wettability gradient.Two components,which are functionalized graphene nanosheets(FGNSs)and carbon nanotubes(FCNTs)both anchoring iron phthalocyanine for oxygen reduction catalysis,are employed as building blocks.The former assemble into fish-scale-like hydrophilic lamellar structure facing the electrolyte,facilitating swift ion infiltration;while the latter arrange into waterspider-leg-like hydrophobic villus structure exposed to ambient air,enhancing rapid oxygen invasion.This asymmetric design(Asy-FCNTs-FGNSs)not only boosts mass transport and expands triple-phase boundary,but also improves structural robustness of the air electrode.The resulting ZAB achieves a high peak power density of 239.3 mW cm^(−2)and a specific capacity of 814.3 mAh g_(Zn)^(−1)(10 mA cm^(−2)),along with outstanding cycling stability,overwhelmingly outperforming conventional symmetric counterparts and prior self-supporting designs.This work presents an innovative architecture-optimization scheme for advanced air electrodes,offering a scalable bioinspired strategy to propel ZAB technology and guide future electrode advancements.
基金supported by the National Natural Science Foundation of China(22579043,52461040,22202053,52274297)the Hainan Provincial Department of Science and Technology(G20250218018E)+2 种基金the first batch of“Nanhai New Star”industrial innovation talent platform project(202309006)the Hainan Province Science and Technology Special Fund(ZDYF2025GXJS004)the Start-up Research Foundation of Hainan University(KYQD(ZR)-21124)。
文摘Membra ne electrode assemblies(MEAs)are pivotal to advancing proton exchange membra ne water electrolysis(PEMWE),yet conventional designs suffer from limited triple-phase boundaries(TPBs),inefficient mass/charge transport,and insufficient durability.This study introduces a three-dimensional ordered pattern-array(3D OPA)architecture fabricated via a scalable laser-machined mask and hot-pressing strategy.The 3D OPA MEA achieves a current density of 3.73 A cm^(-2) at 2 V,demonstrating a 50%performance improvement over the conventional MEA(2.48 A cm^(-2)),alongside a degradation rate of 26.6μV h^(-1) in a highly dynamic accelerated stress test(AST).Additionally,numerical simulations corroborate that the OPA architecture optimizes localized oxygen diffusion and liquid water replenishment,enhancing reaction kinetics.The 3D OPA architecture enhances TPBs and establishes optimized gas-liquid tra nsport pathways,significantly improving catalyst utilization while minimizing mass transfer overpotential and bubble-induced losses.Furthermore,its interlocking design reinforces mechanical interactions,reducing ohmic resistance a nd ensuring sustained mecha nical integrity and electrochemical durability.This work provides a simple,cost-effective,and scalable approach for patterned MEAs,addressing critical barriers to PEMWE commercialization through rational TPB engineering and transport pathway optimization.
基金supported by the Resources Technology and Critical Minerals Trailblazer and the Commonwealth Government through the Trailblazer Universities Programthe grant from Australia's Economic Accelerator(IG240100694)the Australian Research Council Discovery Early Career Researcher Award(Grant No.DE240101013).
文摘Hydrogels and aerogels,with their self-supporting nature and highly porous structures,have emerged as promising electrode materials for energy conversion devices such as fuel cells,batteries,and electrolyzers.Their hierarchical porosity,extended active surface area,and enhanced ion and mass transport properties make them attractive for electrochemical applications.However,achieving an efficient three-phase reaction interface within these 3-dimensional(3D)structures remains a key challenge,as it directly impacts catalytic activity and overall device performance.Recent advancements have focused on tailoring gel properties to optimize electrochemical performance,bridging material synthesis,structural engineering,and device integration to enhance reaction kinetics,durability,and scalability.A deeper understanding of the relationships between gel composition,porosity,surface properties,and electrochemical behavior is essential for developing next-generation energy devices.This review provides a comprehensive analysis of hydrogel-and aerogel-based electrodes,covering their design principles,fabrication strategies,and electrochemical applications.By examining recent progress and key challenges,we offer insights into the bottom-up development of advanced 3D electrodes,aiming to accelerate the practical implementation of gel-based materials in sustainable energy conversion.
基金supported by National Natural Science Foundation of China(Grant 52225204,52173233,and 52402231)the Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-03-E00109)+3 种基金the Program for Professor of Special Appointment(Eastern Scholar)at the Shanghai Institutions of Higher Learning,the Natural Science Foundation of Shanghai(23ZR1479200)“Shuguang Program”supported by the Shanghai Education Development Foundation and Shanghai Municipal Education Commission(20SG33)the Fundamental Research Funds for the Central Universities(2232024Y-01)DHU Distinguished Young Professor Program(LZA2022001).
文摘Precious metal-free electrocatalysts often require significantly more loadings to achieve similar performance as Pt does in fuel cells and metal air batteries.The high loadings cause substantial mass transportation resistance.To address this challenge,we synthesized ordered mesoporous carbon nanofiber electrocatalyst that enables unimpeded mass transfer at mesoscale.The synthesis was based on electrospinning of supramolecular micelles,which were stretched under hydrodynamic forces and self-assembled as in oriented and ordered form.Ordered mesoporous carbon nanofibers(OMCNFs)were obtained after removing the micelle template.The aligned mesopores over electrode scale strongly accelerate diffusion kinetics.The OH−ion diffusion coefficient of OMCNF is 26 times larger than that of the nanofiber with non-ordered pores(NMCNF)and 206 times larger than that of Pt/C.As a result,the electrocatalytic performance of OMCNF was maintained at increased catalyst loadings,while performance deterioration was observed in NMCNF and Pt/C.The assembled zinc-air batteries using aqueous electrolyte and solid-state electrolyte delivered high power density and nice cycling performance.
基金The authors acknowledge support from the National Natural Science Foundation of China(Nos.51402100 and 21573066)the Provincial Natural Science Foundation of Hunan(Nos.2016JJ1006 and 2016TP1009).
文摘Gas-involving electrochemical reactions,like oxygen reduction reaction (ORR),oxygen evolution reaction (OER),and hydrogen evolution reaction (HER),are critical processes for energy-saving,environment-friendly energy conversion and storage technologies which gain increasing attention.The development of according electrocatalysts is key to boost their electrocatalytic performances.Dramatic efforts have been put into the development of advanced electrocatalysts to overcome sluggish kinetics.On the other hand,the electrode interfaces-architecture construction plays an equally important role for practical applications because these imperative electrode reactions generally proceed at triple-phase interfaces of gas,liquid electrolyte,and solid electrocatalyst.A desirable architecture should facilitate the complicate reactions occur at the triple-phase interfaces,which including mass diffusion,surface reaction and electron transfer.In this review,we will summarize some design principles and synthetic strategies for optimizing triple-phase interfaces of gas-involving electrocatalysis systematically,based on the electrode reaction process at the three-phase interfaces.It can be divided into three main optimization directions:exposure of active sites,promotion of mass diffusion and acceleration of electron transfer.Furthermore,we especially highlight several remarkable works with comprehensive optimization about specific energy conversion devices,including metal-air batteries,fuel cells,and water-splitting devices are demonstrated with superb efficiency.In the last section,the perspectives and challenges in the future are proposed.
基金supported by the National Natural Science Foundation of China(Nos.52173222,51622103 and 22109088)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01N111)+1 种基金Key Area Research and Development Program of Guangdong Province(No.2020B0909040003)Shenzhen Science and Technology Innovation Committee(Nos.WDZ20200819115243002 and JCYJ20190809172617313).
文摘Low-platinum(Pt)alloy catalysts hold promising application in oxygen reduction reaction(ORR)electrocatalysis of protonexchange-membrane fuel cells(PEMFCs).Although significant progress has been made to boost the kinetic ORR mass activity at low current densities in liquid half-cells,little attention was paid to the performance of Pt-based catalysts in realistic PEMFCs particularly at high current densities for high power density,which remains poorly understood.In this paper,we show that,regardless of the kinetic mass activity at the low current density region,the high current density performance of the low-Pt alloy catalysts is dominantly controlled by the total Pt surface area,particularly in low-Pt-loading H_(2)–air PEMFCs.To this end,we propose two different strategies to boost the specific Pt surface area,the post-15-nm dealloyed nanoporous architecture and the sub-5-nm solid core–shell nanoparticles(NPs)through fluidic-bed synthesis,both of which bring in comparably high mass activity and high Pt surface area for large-current-density performance.At medium current density,the dealloyed porous NPs provide substantially higher H_(2)–air PEMFC performance compared to solid core–shell catalysts,despite their similar mass activity in liquid half-cells.Scanning transmission electron microscopy images combined with electron energy loss spectroscopic imaging evidence a previously unreported“semi-immersed nanoporous-Pt/ionomer”structure in contrast to a“fully-immersed core–shellPt/ionomer”structure,thus favoring O_(2) transport and improving the fuel cell performance.Our results provide new insights into the role of Pt nanostructures in concurrently optimizing the mass activity,Pt surface area and Pt/Nafion interface for high power density fuel cells.
