Study on gas–liquid flow in stirred tank with two combinations of dual-impeller(six-bent-bladed turbine(6BT)+six-inclined-blade down-pumping turbine(6 ITD),the six-bent-bladed turbine(6BT)+six-inclinedblade up-pumpin...Study on gas–liquid flow in stirred tank with two combinations of dual-impeller(six-bent-bladed turbine(6BT)+six-inclined-blade down-pumping turbine(6 ITD),the six-bent-bladed turbine(6BT)+six-inclinedblade up-pumping turbine(6ITU))was conducted using computational fluid dynamics(CFD)and population balance model(PBM)(CFD-PBM)coupled model.The local bubble size was captured by particle image velocimetry(PIV)measurement.The gas holdup,bubble size distribution and gas–liquid interfacial area were explored at different conditions through numerical simulation.The results showed that the 4 mm bubbles accounted for the largest proportion of 33%at the gas flow rates Q=0.76 m^(3)·h^(-1) and 22%at Q=1.52 m^(3)·h^(-1) for combined impeller of 6BT+6ITU,while the bubbles of 4.7 mm and 5.5 mm were the largest proportion for 6BT+6ITD combination,i.e.25%at Q=0.76 m^(3)·h^(-1) and 22%at Q=1.52 m^(3)·h^(-1),respectively,which indicated that 6BT+6ITU could reduce bubble size effectively and promote gas dispersion.In addition,the gas holdup around impellers was increased obviously with the speed compared with gas flow rate.So it was concluded that 6ITU impeller could be more conductive to the bubble dispersion with more uniform bubble size,which embodied the advantages of 6BT+6ITU combination in gas–liquid mixing.展开更多
Developing high-performance,durable,and cost-effective oxygen reduction reaction(ORR)catalysts is essential for advancing next-generation energy devices like zinc-air batteries(ZABs).Herein,we engineer a hybrid Fe-N-C...Developing high-performance,durable,and cost-effective oxygen reduction reaction(ORR)catalysts is essential for advancing next-generation energy devices like zinc-air batteries(ZABs).Herein,we engineer a hybrid Fe-N-C catalyst(FeSA-Fe_(NP)/CeO_(2)@NC)integrating atomically dispersed Fe-Nx sites,Fe nanoparticles,and oxygen vacancy-rich CeO_(2) nanoparticles within a nitrogen-doped carbon matrix.Interfacial charge transfer and oxygen vacancy-mediated electron redistribution,synergistically enhanced by strong metal-support interactions(SMSI),optimize the electronic configuration of Fe-Nx sites and reduce their electron density.The resulting catalyst exhibits exceptional ORR activity and stability,featuring a half-wave potential of 0.925 V(vs.RHE)in alkaline media and minimal degradation(1%and 2.8%negative shifts after 10,000/20,000 cycles).In ZABs,it achieves a peak power density of 310.29 mW·cm-2 while sustaining stable operation for over 600 h.This work demonstrates dual role of CeO_(2) in enhancing activity and stability,establishing a design principle for high-performance electrocatalysts in energy conversion systems.展开更多
Recent decades have witnessed the rapid development of catalytic science,especially after Taylor and Armstrong proposed the notion of the“active site”in 1925.By optimizing reaction paths and reducing the activation ...Recent decades have witnessed the rapid development of catalytic science,especially after Taylor and Armstrong proposed the notion of the“active site”in 1925.By optimizing reaction paths and reducing the activation energies of reactions,catalysts appear in more than 90%of chemical production reactions,involving homogeneous catalysis,heterogeneous catalysis,and enzyme catalysis.Because of the 100%efficiency of active atom utilization and the adjustable microenvironment of metal centers,single-atom catalysts(SACs)shine in various catalytic fields for enhancing the rate,conversion,and selectivity of chemical reactions.Nevertheless,a solo active site determines a fixed adsorption mode,and the adsorption energies of intermediates from multistep reactions linking with a solo metal site are related to each other.For a specific multistep reaction,it is almost impossible to optimally adjust the adsorption of every intermediate on the solo site simultaneously.This phenomenon is termed the scaling relationship limit(SRL)and is an unavoidable obstacle in the development of pure SACs.Dual-atom catalysts(DACs),perfectly inheriting the advantages of SACs,can exhibit better catalytic performance than simple SACs and thus have gradually gained researchers’attention.Depending on the dual-metal structure,dual-metal sites(DMSs)in DACs can be divided into two separated heterometal sites,two linked homometal sites,and two linked heterometal sites.Two separated heterometal sites prescribe a distance limit between two metal sites for electron interaction.Currently,the active origins of DACs can be summarized in the following three points:(1)electronic effect,in which only one metal center serves as active site and the other plays an electronic regulatory role;(2)synergistic effect,in which two metal centers separately catalyze different core steps to improve catalytic performance together;(3)adsorption effect,in which offering additional sites changes the adsorption structures to break the SRL based on SACs.Among the three active origins,optimizing the adsorption structure of intermediates upon DMSs is one of the most effective technologies to boost the catalytic property of DACs on the basis of SACs.To date,few contributions have focused on the development of DACs in various heterogeneous catalysis environments,including O_(2) reduction reaction,O_(2) evolution reaction,H_(2) evolution reaction,CO_(2) reduction reaction,N_(2) reduction reaction,and other conversion reactions.In this Account,a summary of recent progress regarding DACs in heterogeneous catalysis will be presented.First,the evolution of DACs from an unpopular discovery to research hot spot is illustrated through a timeline.In the next section,the DACs are divided into three categories,and the potential active origins of DACs are revealed by comparison with SACs.In addition,the techniques for constructing DACs are systematically summarized,including preparation of carbonous,pyrolysis-free,noncarbon-supported,and complex-type DACs.Furthermore,the underlying active origins of DACs in specific energy-and environment-related reactions are introduced in detail with assistance of theoretical calculations.Finally,we affirm the contribution of DACs to catalysis,particularly heterogeneous electrocatalysis,and provide an outlook regarding the development direction for DACs by discussing the major challenges.It is anticipated that this Account can inspire researchers to propel the advance of DACs.展开更多
Developing exceptionally durable and efficient oxygen reduction reaction(ORR)catalysts is of paramount importance to the widespread commercialization of proton exchange membrane fuel cells(PEMFCs)but is still challeng...Developing exceptionally durable and efficient oxygen reduction reaction(ORR)catalysts is of paramount importance to the widespread commercialization of proton exchange membrane fuel cells(PEMFCs)but is still challenging.Herein,PtCu nanoalloys rooted on nitrogen-doped carbon nanosheets(PtCuNC-700)with fully exposed PtCu nanoalloys and strong metal–support interaction were developed.Benefiting from its structural and compositional merits,PtCuNC-700 showcases superior ORR activity and stability with a specific activity of 1.05mA cm^(−2)and mass activity of 0.45 A mgPt^(−1),4.2-fold and 3.7-fold higher than Pt/C(0.25 mA cm^(−2)and 0.12 A mgPt^(−1)),respectively.Moreover,PtCuNC-700 exhibits first-class performance in H2/air PEMFC assessment and delivers a peak power density of 929.7 mW cm^(−2)and excellent cycling stability up to 30,000 cycles.Theoretical calculations disclose that the synergistic effect of alloying Pt with Cu combined with the strong interaction between PtCu nanoalloys and nitrogen-doped carbon nanosheets can effectively modify the local electron configuration and density of states of Pt sites approaching the Fermi level.Hence,the PtCu-alloy catalysts realized here diminish the energy barrier for ORR and accelerate their reaction kinetics.This work provides a reliable and effective approach to boost the activity and stability of Pt alloy-based ORR electrocatalysts in PEMFCs.展开更多
Gel polymer electrolytes(GPEs)are conceived to be a good way to build safer lithium/sodium metal batteries by substituting traditional liquid electrolytes.However;it is still very difficult for GPEs to simultaneously ...Gel polymer electrolytes(GPEs)are conceived to be a good way to build safer lithium/sodium metal batteries by substituting traditional liquid electrolytes.However;it is still very difficult for GPEs to simultaneously achieve high room-temperature ionic conductivity;uniform Na^(+) flow;superior interfacial compatibility;and increased mechanical strength.Herein;a composite gel electrolyte(KNT-PTGPE)with high ionic conductivity of 4.06 mS cm^(-1) is prepared through chemical crosslinking strategy and the introduction of inorganic nanoparticles.The hybrid gel polymer network is formed by in situ cross-linking modified TiO_(2)(KNT);three-armed trimethylolpropane trimethacrylate and poly(ethylene glycol)diacrylate.The resulting 3D interpenetrating network facilitates the absorption of liquid electrolytes and improves the mechanical properties of electrolyte.Theoretical calculation and in situ measurements reveal that the homogeneous TiO_(2) fillers with abundant Lewis acid site and polymer network are involved in the solvation process of Na+;thus constructing a fast Na+transport channel.Consequently;a stable plating/stripping process lasting over 900 h is achieved due to the uniform distribution of Na+flux and the good mechanical properties of the electrolyte;and the assembled cell exhibits an excellent long-term cycling stability.The approach offers more opportunities to design GPEs for high performance SMBs.展开更多
The development of low-cost and eco-friendly aqueous electrolytes with a wide voltage window is the key to achieving safe high energy density supercapacitors(SCs).In this work,a molecular crowding electrolyte is prepa...The development of low-cost and eco-friendly aqueous electrolytes with a wide voltage window is the key to achieving safe high energy density supercapacitors(SCs).In this work,a molecular crowding electrolyte is prepared by simulating the crowded environment in living cells.Ion transport in the molecular crowding electrolyte can be effectively improved via reducing the molecular weight of the crowding agent,polyethylene glycol(PEG).The results show that PEG with a molecular weight of 200(PEG200)can significantly improve ionic conductivity while maintaining a wide voltage window.These advantages enable commercial activated carbon-based SCs to work at 2.5 V with high energy density,outstanding rate performance and good stability for more than 10,000 cycles.On this basis,three series of molecular crowding electrolytes using sodium perchlorate,lithium perchlorate,and sodium trifluoromethanesulfonate as salts are developed,demonstrating the versatility of PEG200 for wide-voltage aqueous electrolytes.展开更多
Metal porphyrins are star molecules that possess welldefined coordination metal centers for versatile catalytic reactions.However,most previous work has focused on the correlations between in-plane symmetric configura...Metal porphyrins are star molecules that possess welldefined coordination metal centers for versatile catalytic reactions.However,most previous work has focused on the correlations between in-plane symmetric configuration of metal-N_(4)sites and their catalytic performance.Addressing the catalytic contribution of additional axial coordination to such symmetric configuration remains a challenge.Theoretical calculations revealed that axially anchoring an extra pyridine on the tetra-coordinated cobalt porphyrin(Co-N4)to construct penta-coordinated cobalt porphyrin(Co-N_(5))renders cobalt a higher electron density,thereby favoring the rate-determining O_(2)adsorption/activation and reducing the oxygen electroreduction barrier.Therefore,a well-defined Co-N_(5)site is rationally introduced into the azo-linked polymer framework for a fundamental structure-catalytic performance correlation study.As-prepared Co-N_(5)catalyst exhibits a 26 mV positive shift in half-wave potential compared with the pyridine-free Co-N_(4)counterpart,discloses a markedly higher power density(141.4 mW cm^(−2)),and possesses better long-term durability(over 160 h cycles)in a Zn-air battery.Moreover,such a Co-N_(5)catalyst also showcases potential applications for CO_(2)reduction with high CO_(2)-to-CO conversion faradic efficiency and better selectivity than the Co-N_(4)counterpart because coordination of the fifth pyridine evokes electronic localization that suppresses a competitive side reaction.This work proves the positive electrocatalytic contribution of axial penta-coordination on well-defined metalporphyrin-based catalysts and offers atomic understanding of the structure-performance correlation on single atom catalysts for future catalyst design.展开更多
Manufacturing cost-effective electrolytes featuring high(electro)chemical stability,high Zn anode reversibility,good ionic conductivity,and environmental benignity is highly desired for rechargeable aqueous zinc-based...Manufacturing cost-effective electrolytes featuring high(electro)chemical stability,high Zn anode reversibility,good ionic conductivity,and environmental benignity is highly desired for rechargeable aqueous zinc-based energy storage devices but remains a great challenge.Herein,a solute-solvent dual engineering strategy using lithium bis(trifluoromethane)sulfonimide(LiTFSI)and inexpensive poly(ethylene glycol)(PEG,M_(n)=200)as a coadditive with an optimized ratio accomplished an all-round performance enhancement of electrolytes.Due to the synergistic inhibition of water activity and Zn^(2+)solvation structure reorganization by LiTFSI-PEG,as well as a stable F-rich interfacial layer and PEG adsorption on the Zn anode surface,dendrite-free Zn plating/stripping at nearly 100%Coulombic efficiency and stable cycling performance over 2000 h at 0.5 mA cm^(−2)was achieved.Importantly,the integrated Zn-ion hybrid supercapacitors are endowed with a wide voltage window of 0-2.2 V,superb cycling stability up to 10,000 cycles,and excellent temperature adaptability from-40°C to 50°C.The highest cutoffvoltage reached 2.1 V in Zn//LiMn_(2)O_(4)and Zn//VOPO_(4)full cells with a stable lifespan over 500 cycles.This work provides a promising strategy for the development of aqueous electrolytes with excellent com-prehensive properties for zinc-based energy storage.展开更多
基金supported by the National Natural Science Foundation of China(52176040)Shandong Provincial Natural Science Foundation of China(ZR2018LE015)。
文摘Study on gas–liquid flow in stirred tank with two combinations of dual-impeller(six-bent-bladed turbine(6BT)+six-inclined-blade down-pumping turbine(6 ITD),the six-bent-bladed turbine(6BT)+six-inclinedblade up-pumping turbine(6ITU))was conducted using computational fluid dynamics(CFD)and population balance model(PBM)(CFD-PBM)coupled model.The local bubble size was captured by particle image velocimetry(PIV)measurement.The gas holdup,bubble size distribution and gas–liquid interfacial area were explored at different conditions through numerical simulation.The results showed that the 4 mm bubbles accounted for the largest proportion of 33%at the gas flow rates Q=0.76 m^(3)·h^(-1) and 22%at Q=1.52 m^(3)·h^(-1) for combined impeller of 6BT+6ITU,while the bubbles of 4.7 mm and 5.5 mm were the largest proportion for 6BT+6ITD combination,i.e.25%at Q=0.76 m^(3)·h^(-1) and 22%at Q=1.52 m^(3)·h^(-1),respectively,which indicated that 6BT+6ITU could reduce bubble size effectively and promote gas dispersion.In addition,the gas holdup around impellers was increased obviously with the speed compared with gas flow rate.So it was concluded that 6ITU impeller could be more conductive to the bubble dispersion with more uniform bubble size,which embodied the advantages of 6BT+6ITU combination in gas–liquid mixing.
基金support from the National Key R&D Program of China:Strategic International Innovation Cooperation(2024YFE020940O)the National Natural Science Foundation of China(52373187,52573228)+1 种基金the National Youth Top-notch Talent Support Program of China,the Natural Science Foundation of Jiangxi Province(20224ACB204006)the"Double Thousand Plan"Science and Technology Innovation High-End Talent Project of Jiangxi Province(jxsq2023201094).
文摘Developing high-performance,durable,and cost-effective oxygen reduction reaction(ORR)catalysts is essential for advancing next-generation energy devices like zinc-air batteries(ZABs).Herein,we engineer a hybrid Fe-N-C catalyst(FeSA-Fe_(NP)/CeO_(2)@NC)integrating atomically dispersed Fe-Nx sites,Fe nanoparticles,and oxygen vacancy-rich CeO_(2) nanoparticles within a nitrogen-doped carbon matrix.Interfacial charge transfer and oxygen vacancy-mediated electron redistribution,synergistically enhanced by strong metal-support interactions(SMSI),optimize the electronic configuration of Fe-Nx sites and reduce their electron density.The resulting catalyst exhibits exceptional ORR activity and stability,featuring a half-wave potential of 0.925 V(vs.RHE)in alkaline media and minimal degradation(1%and 2.8%negative shifts after 10,000/20,000 cycles).In ZABs,it achieves a peak power density of 310.29 mW·cm-2 while sustaining stable operation for over 600 h.This work demonstrates dual role of CeO_(2) in enhancing activity and stability,establishing a design principle for high-performance electrocatalysts in energy conversion systems.
基金financially supported by the National Natural Science Foundation of China(52073137 and 51763018).
文摘Recent decades have witnessed the rapid development of catalytic science,especially after Taylor and Armstrong proposed the notion of the“active site”in 1925.By optimizing reaction paths and reducing the activation energies of reactions,catalysts appear in more than 90%of chemical production reactions,involving homogeneous catalysis,heterogeneous catalysis,and enzyme catalysis.Because of the 100%efficiency of active atom utilization and the adjustable microenvironment of metal centers,single-atom catalysts(SACs)shine in various catalytic fields for enhancing the rate,conversion,and selectivity of chemical reactions.Nevertheless,a solo active site determines a fixed adsorption mode,and the adsorption energies of intermediates from multistep reactions linking with a solo metal site are related to each other.For a specific multistep reaction,it is almost impossible to optimally adjust the adsorption of every intermediate on the solo site simultaneously.This phenomenon is termed the scaling relationship limit(SRL)and is an unavoidable obstacle in the development of pure SACs.Dual-atom catalysts(DACs),perfectly inheriting the advantages of SACs,can exhibit better catalytic performance than simple SACs and thus have gradually gained researchers’attention.Depending on the dual-metal structure,dual-metal sites(DMSs)in DACs can be divided into two separated heterometal sites,two linked homometal sites,and two linked heterometal sites.Two separated heterometal sites prescribe a distance limit between two metal sites for electron interaction.Currently,the active origins of DACs can be summarized in the following three points:(1)electronic effect,in which only one metal center serves as active site and the other plays an electronic regulatory role;(2)synergistic effect,in which two metal centers separately catalyze different core steps to improve catalytic performance together;(3)adsorption effect,in which offering additional sites changes the adsorption structures to break the SRL based on SACs.Among the three active origins,optimizing the adsorption structure of intermediates upon DMSs is one of the most effective technologies to boost the catalytic property of DACs on the basis of SACs.To date,few contributions have focused on the development of DACs in various heterogeneous catalysis environments,including O_(2) reduction reaction,O_(2) evolution reaction,H_(2) evolution reaction,CO_(2) reduction reaction,N_(2) reduction reaction,and other conversion reactions.In this Account,a summary of recent progress regarding DACs in heterogeneous catalysis will be presented.First,the evolution of DACs from an unpopular discovery to research hot spot is illustrated through a timeline.In the next section,the DACs are divided into three categories,and the potential active origins of DACs are revealed by comparison with SACs.In addition,the techniques for constructing DACs are systematically summarized,including preparation of carbonous,pyrolysis-free,noncarbon-supported,and complex-type DACs.Furthermore,the underlying active origins of DACs in specific energy-and environment-related reactions are introduced in detail with assistance of theoretical calculations.Finally,we affirm the contribution of DACs to catalysis,particularly heterogeneous electrocatalysis,and provide an outlook regarding the development direction for DACs by discussing the major challenges.It is anticipated that this Account can inspire researchers to propel the advance of DACs.
基金support from the National Natural Science Foundation of China(grant nos.52073137,51763018,U20A20246)the Fundamental Research Funds for the Central Universities(Innovation funded Projects,no.2022CXZZ104).
文摘Developing exceptionally durable and efficient oxygen reduction reaction(ORR)catalysts is of paramount importance to the widespread commercialization of proton exchange membrane fuel cells(PEMFCs)but is still challenging.Herein,PtCu nanoalloys rooted on nitrogen-doped carbon nanosheets(PtCuNC-700)with fully exposed PtCu nanoalloys and strong metal–support interaction were developed.Benefiting from its structural and compositional merits,PtCuNC-700 showcases superior ORR activity and stability with a specific activity of 1.05mA cm^(−2)and mass activity of 0.45 A mgPt^(−1),4.2-fold and 3.7-fold higher than Pt/C(0.25 mA cm^(−2)and 0.12 A mgPt^(−1)),respectively.Moreover,PtCuNC-700 exhibits first-class performance in H2/air PEMFC assessment and delivers a peak power density of 929.7 mW cm^(−2)and excellent cycling stability up to 30,000 cycles.Theoretical calculations disclose that the synergistic effect of alloying Pt with Cu combined with the strong interaction between PtCu nanoalloys and nitrogen-doped carbon nanosheets can effectively modify the local electron configuration and density of states of Pt sites approaching the Fermi level.Hence,the PtCu-alloy catalysts realized here diminish the energy barrier for ORR and accelerate their reaction kinetics.This work provides a reliable and effective approach to boost the activity and stability of Pt alloy-based ORR electrocatalysts in PEMFCs.
基金supported by the National Natural Science Foundation of China(52333006)the Natural Science Foundation of Jiangxi Province(20232BAB213024)the Science and Technology Research Project of Jiangxi Provincial Department of Education(GJJ2200312).
文摘Gel polymer electrolytes(GPEs)are conceived to be a good way to build safer lithium/sodium metal batteries by substituting traditional liquid electrolytes.However;it is still very difficult for GPEs to simultaneously achieve high room-temperature ionic conductivity;uniform Na^(+) flow;superior interfacial compatibility;and increased mechanical strength.Herein;a composite gel electrolyte(KNT-PTGPE)with high ionic conductivity of 4.06 mS cm^(-1) is prepared through chemical crosslinking strategy and the introduction of inorganic nanoparticles.The hybrid gel polymer network is formed by in situ cross-linking modified TiO_(2)(KNT);three-armed trimethylolpropane trimethacrylate and poly(ethylene glycol)diacrylate.The resulting 3D interpenetrating network facilitates the absorption of liquid electrolytes and improves the mechanical properties of electrolyte.Theoretical calculation and in situ measurements reveal that the homogeneous TiO_(2) fillers with abundant Lewis acid site and polymer network are involved in the solvation process of Na+;thus constructing a fast Na+transport channel.Consequently;a stable plating/stripping process lasting over 900 h is achieved due to the uniform distribution of Na+flux and the good mechanical properties of the electrolyte;and the assembled cell exhibits an excellent long-term cycling stability.The approach offers more opportunities to design GPEs for high performance SMBs.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(52073137,51763018,21704038)the NSFC-DFG Joint Research Project(51761135114)the Natural Science Foundation of Jiangxi Province(20203BDH80W011,20202ZDB01009,20192BCB23001).
文摘The development of low-cost and eco-friendly aqueous electrolytes with a wide voltage window is the key to achieving safe high energy density supercapacitors(SCs).In this work,a molecular crowding electrolyte is prepared by simulating the crowded environment in living cells.Ion transport in the molecular crowding electrolyte can be effectively improved via reducing the molecular weight of the crowding agent,polyethylene glycol(PEG).The results show that PEG with a molecular weight of 200(PEG200)can significantly improve ionic conductivity while maintaining a wide voltage window.These advantages enable commercial activated carbon-based SCs to work at 2.5 V with high energy density,outstanding rate performance and good stability for more than 10,000 cycles.On this basis,three series of molecular crowding electrolytes using sodium perchlorate,lithium perchlorate,and sodium trifluoromethanesulfonate as salts are developed,demonstrating the versatility of PEG200 for wide-voltage aqueous electrolytes.
基金financially supported by the National Natural Science Foundation of China(grant nos.52073137 and 51763018).
文摘Metal porphyrins are star molecules that possess welldefined coordination metal centers for versatile catalytic reactions.However,most previous work has focused on the correlations between in-plane symmetric configuration of metal-N_(4)sites and their catalytic performance.Addressing the catalytic contribution of additional axial coordination to such symmetric configuration remains a challenge.Theoretical calculations revealed that axially anchoring an extra pyridine on the tetra-coordinated cobalt porphyrin(Co-N4)to construct penta-coordinated cobalt porphyrin(Co-N_(5))renders cobalt a higher electron density,thereby favoring the rate-determining O_(2)adsorption/activation and reducing the oxygen electroreduction barrier.Therefore,a well-defined Co-N_(5)site is rationally introduced into the azo-linked polymer framework for a fundamental structure-catalytic performance correlation study.As-prepared Co-N_(5)catalyst exhibits a 26 mV positive shift in half-wave potential compared with the pyridine-free Co-N_(4)counterpart,discloses a markedly higher power density(141.4 mW cm^(−2)),and possesses better long-term durability(over 160 h cycles)in a Zn-air battery.Moreover,such a Co-N_(5)catalyst also showcases potential applications for CO_(2)reduction with high CO_(2)-to-CO conversion faradic efficiency and better selectivity than the Co-N_(4)counterpart because coordination of the fifth pyridine evokes electronic localization that suppresses a competitive side reaction.This work proves the positive electrocatalytic contribution of axial penta-coordination on well-defined metalporphyrin-based catalysts and offers atomic understanding of the structure-performance correlation on single atom catalysts for future catalyst design.
基金the National Natural Science Foundation of China(52073137,51763018)the International Science and Technology Cooperation of Jiangxi Province(20203BDH80W011)the Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education,Jiangxi Normal University(KFSEMC-202204).
文摘Manufacturing cost-effective electrolytes featuring high(electro)chemical stability,high Zn anode reversibility,good ionic conductivity,and environmental benignity is highly desired for rechargeable aqueous zinc-based energy storage devices but remains a great challenge.Herein,a solute-solvent dual engineering strategy using lithium bis(trifluoromethane)sulfonimide(LiTFSI)and inexpensive poly(ethylene glycol)(PEG,M_(n)=200)as a coadditive with an optimized ratio accomplished an all-round performance enhancement of electrolytes.Due to the synergistic inhibition of water activity and Zn^(2+)solvation structure reorganization by LiTFSI-PEG,as well as a stable F-rich interfacial layer and PEG adsorption on the Zn anode surface,dendrite-free Zn plating/stripping at nearly 100%Coulombic efficiency and stable cycling performance over 2000 h at 0.5 mA cm^(−2)was achieved.Importantly,the integrated Zn-ion hybrid supercapacitors are endowed with a wide voltage window of 0-2.2 V,superb cycling stability up to 10,000 cycles,and excellent temperature adaptability from-40°C to 50°C.The highest cutoffvoltage reached 2.1 V in Zn//LiMn_(2)O_(4)and Zn//VOPO_(4)full cells with a stable lifespan over 500 cycles.This work provides a promising strategy for the development of aqueous electrolytes with excellent com-prehensive properties for zinc-based energy storage.
