Aqueous organic redox flow batteries(AORFBs),which exploit the reversible electrochemical reactions of water-soluble organic electrolytes to store electricity,have emerged as an efficient electrochemical energy storag...Aqueous organic redox flow batteries(AORFBs),which exploit the reversible electrochemical reactions of water-soluble organic electrolytes to store electricity,have emerged as an efficient electrochemical energy storage technology for the grid-scale integration of renewable electricity.pH-neutral AORFBs that feature high safety,low corrosivity,and environmental benignity are particularly promising,and their battery performance is significantly impacted by redox-active molecules and ion-exchange membranes(IEMs).Here,representative anolytes and catholytes engineered for use in pH-neutral AORFBs are outlined and summarized,as well as their side reactions that cause irreversible battery capacity fading.In addition,the recent achievements of IEMs for pH-neutral AORFBs are discussed,with a focus on the construction and tuning of ion transport channels.Finally,the critical challenges and potential research opportunities for developing practically relevant pH-neutral AORFBs are presented.展开更多
Railway terminal is an important part of railway network. Transport organization of railway terminal is the key of the railway transport organization. Moreover, the organization of transport work is based on the organ...Railway terminal is an important part of railway network. Transport organization of railway terminal is the key of the railway transport organization. Moreover, the organization of transport work is based on the organization of wagon flows in the railway terminal. Because of the great amounts of equipment and a large number of train operations, the study on railway terminal transport organization is mostly focused on a marshalling station in railway terminal or a part of it. Systematic study taking railway terminal as a whole is very few. In this paper, the organization of wagon flows in a railway terminal is analyzed and a wagon flow model in a railway terminal is established. The main principles of organization of local trains are also presented.展开更多
Viologens known as a kind of promising negolyte materials for aqueous organic redox flow batteries,face a critical stability challenge due to the S_N2 nucleophilic attack by hydroxide ions(OH-)during the battery cycli...Viologens known as a kind of promising negolyte materials for aqueous organic redox flow batteries,face a critical stability challenge due to the S_N2 nucleophilic attack by hydroxide ions(OH-)during the battery cycling.In this work,a N-cyclic quaternary ammonium-grafted viologen molecule,viz.1,1'-bis(4,4'-dime thylpiperidiniumyl)-4,4'-bipyridinium tetrachloride((DBPPy)Cl_(4)),is developed by the molecular engineering strategy.The obtained(DBPPy)Cl_(4) molecule shows a decent solubility of 1.84 M and a redox potential of-0.52 V vs.Ag/AgCl,Experimental and theoretical results reveal that the grafted N-cyclic quaternary ammonium groups act as the steric hindrance to prevent nucleophilic attack by OH~-,increasing the alkali resistance of the electroactive molecule.The symmetrical battery with 0.50 M(DBPPy)Cl4shows negligible decay during the 13-day cycling test.As demonstration,the flow battery utilizing 1.0 M(DBPPy)Cl_(4) as the negolyte and 1-(1-oxyl-2,2',6,6'-tetramethylpiperidin-4-yl)-1'-(3-(trimethylammonio)propyl)-4,4'-bipyridinium trichloride as the posolyte exhibits a high capacity retention rate of 99.99%per cycle at 60 mA cm^(-2).展开更多
CaN nanorods are successfully fabricated by adjusting the flow rate ratio of hydrogen （H2）/nitrogen （N2） and growth temperature of the selective area growth （SAG） method with metal organic chemical vapor deposit...CaN nanorods are successfully fabricated by adjusting the flow rate ratio of hydrogen （H2）/nitrogen （N2） and growth temperature of the selective area growth （SAG） method with metal organic chemical vapor deposition （MOCVD）. The SAG template is obtained by nanospherical-lens photolithography. It is found that increasing the flow rate of 1-12 will change the CaN crystal shape from pyramid to vertical rod, while increasing the growth temperature will reduce the diameters of GaN rods to nanometer scale. Finally the CaN nanorods with smooth lateral surface and relatively good quality are obtained under the condition that the H2：N2 ratio is 1：1 and the growth temperature is 1030℃. The good crystal quality and orientation of GaN nanorods are confirmed by high resolution transmission electron microscopy. The cathodoluminescence spectrum suggests that the crystal and optical quality is also improved with increasing the temperature.展开更多
The entropy balance equation that describes the entropy budget of atmospheric systems is derived from the Gibbs relation.The distribution of the entropy flows of a west-Pacific typhoon and a Bengal-Bay cyclone is calc...The entropy balance equation that describes the entropy budget of atmospheric systems is derived from the Gibbs relation.The distribution of the entropy flows of a west-Pacific typhoon and a Bengal-Bay cyclone is calculated and thus the dissipativity of the atmospheric systems is revealed.展开更多
in this paper, a general integer prosramming model is set up, and its solution ispresented to optimize the organization of wagon flows and the determination ofthe train running route as well as division of shuntins wo...in this paper, a general integer prosramming model is set up, and its solution ispresented to optimize the organization of wagon flows and the determination ofthe train running route as well as division of shuntins work among stations in ahub. As application example is put forword, with some conclusions reached.展开更多
Five-membered pyrroline nitroxides with high-potential is fascinating as catholyte for aqueous organic redox flow batteries(AORFBs),however,it suffers from a primary deficiency of insufficient stability due to ring-op...Five-membered pyrroline nitroxides with high-potential is fascinating as catholyte for aqueous organic redox flow batteries(AORFBs),however,it suffers from a primary deficiency of insufficient stability due to ring-opening side reaction.Herein we report a spatial structure regulation strategy by host-guest chemistry,encapsulating 3-carbamoyl-2,2,5,5-tetramethylpyrroline-1-oxyl(CPL)into hydrosoluble cyclodextrins(CDs)with an inclusion structure of N–O⋅head towards cavity bottom,to boost the solubility and cyclability of pyrroline nitroxides significantly.The armor-clad CPL(CPL⊂HP-β-CD)catholyte in 0.05–0.5 M presents a battery capacity fade rate as low as 0.002%/cycle(0.233%/day)compared to the sole CPL in 0.05 M(0.039%/cycle or 5.23%/day)over 500 cycles in assembled AORFBs.The optimized reclining spatial structure with N–O⋅head towards CD cavity bottom effectively inhibits the attack of Lewis base species on the hydrogen abstraction site in pyrroline ring,and thus avoids the ring-opening side reaction of pyrroline nitroxides.展开更多
Aqueous organic flow batteries have attracted dramatic attention for stationary energy storage due to their resource sustainability and low cost. However, the current reported systems can normally be operated stably u...Aqueous organic flow batteries have attracted dramatic attention for stationary energy storage due to their resource sustainability and low cost. However, the current reported systems can normally be operated stably under a nitrogen or argon atmosphere due to their poor stability. Herein a stable airinsensitive biphenol derivative cathode, 3,30,5,50-tetramethylaminemethylene-4,40-biphenol(TABP), with high solubility(>1.5 mol L^(-1)) and redox potential(0.91 V vs. SHE) is designed and synthesized by a scalable one-step method. Paring with silicotungstic acid(SWO), an SWO/TABP flow battery shows a stable performance of zero capacity decay over 900 cycles under the air atmosphere. Further, an SWO/TABP flow battery manifests a high rate performance with an energy efficiency of 85% at a current density of60 m A cm^(-2) and a very high volumetric capacity of more than 47 Ah L^(-1). This work provides a new and practical option for next-generation practical large-scale energy storage.展开更多
With the deployment of renewable energy and the increasing demand for power grid modernization,redox flow battery has attracted a lot of research interest in recent years.Among the available energy storage technologie...With the deployment of renewable energy and the increasing demand for power grid modernization,redox flow battery has attracted a lot of research interest in recent years.Among the available energy storage technologies,the redox flow battery is considered the most promising candidate battery due to its unlimited capacity,design flexibility,and safety.In this review,we summarize the latest progress and improvement strategies of common inorganic redox flow batteries,such as vanadium redox flow batteries,iron-chromium redox flow batteries,and zinc-based redox flow batteries,including electrolyte,membrane,electrode,structure design,etc.In addition,we introduce the latest progress in aqueous and non-aqueous organic redox flow batteries.We also focus on the modification mechanism,optimization design,improvement strategy,and modeling method of the redox flow battery reaction.Finally,this review presents a brief summary,challenges,and perspectives of the redox flow battery.展开更多
Two-electron neutral aqueous organic redox flow batteries(AORFBs)hold more promising applications in the power grid than one-electron batteries because of their higher capacity.However,their development is strongly li...Two-electron neutral aqueous organic redox flow batteries(AORFBs)hold more promising applications in the power grid than one-electron batteries because of their higher capacity.However,their development is strongly limited by the structural instability of the highly reduced species.By combining the extendedπ-conjugation structure of the anolytes and the enhanced aromaticity of the highly reduced species,we reported a series of highly conjugated and inexpensive arylene diimide derivatives(NDI,PDI,and TPDI)as novel two-electron storage anolyte materials for ultrastable AORFBs.Matched with(ferrocenylmethyl)trimethylammonium chloride(FcNCl)as catholyte,arylene diimide derivative-based AORFBs showed the highest stability in two-electron AORFBs to date.The NDI/FcNCl-based AORFB delivered 98.44%capacity retention at 40 mA cm^(−2)for 350 cycles;TPDI/FcNCl-based AORFB also showed remarkable stability with 97.22%capacity retention at 20 mA cm^(−2)over 200 cycles.This finding lays the theoretical foundation and offers a reference for improving the stability of two-electron AORFBs.展开更多
Fouling behavior along the length of membrane module was systematically investigated by performing simple modeling and lab-scale experiments of forward osmosis （FO） membrane process. The flux distribution model deve...Fouling behavior along the length of membrane module was systematically investigated by performing simple modeling and lab-scale experiments of forward osmosis （FO） membrane process. The flux distribution model developed in this study showed a good agreement with experimental results, validating the robustness of the model. This model demonstrated, as expected, that the permeate flux decreased along the membrane channel due to decreasing osmotic pressure differential across the FO membrane. A series of fouling experiments were conducted under the draw and feed solutions at various recoveries simulated by the model. The simulated fouling experiments revealed that higher organic （alginate） fouling and thus more flux decline were observed at the last section of a membrane channel, as foulants in feed solution became more concentrated. Furthermore, the water flux in FO process declined more severely as the recovery increased due to more foulants transported to membrane surface with elevated solute concentrations at higher recovery, which created favorable solution environments for organic adsorption. The fouling reversibility also decreased at the last section of the membrane channel, suggesting that fouling distribution on FO membrane along the module should be carefully examined to improve overall cleaning efficiency. Lastly, it was found that such fouling distribution observed with co-current flow operation became less pronounced in counter- current flow operation of FO membrane process.展开更多
基金funded by the National Key Research and Development Program of China(Nos.2022YFB3805303,2022YFB3805304)the National Natural Science Foundation of China(Grant/Award Numbers:22308345,U20A20127)+1 种基金the Anhui Provincial Natural Science Foundation(No.2308085QB68)the Fundamental Research Funds for the Central Universities(No.WK2060000059).
文摘Aqueous organic redox flow batteries(AORFBs),which exploit the reversible electrochemical reactions of water-soluble organic electrolytes to store electricity,have emerged as an efficient electrochemical energy storage technology for the grid-scale integration of renewable electricity.pH-neutral AORFBs that feature high safety,low corrosivity,and environmental benignity are particularly promising,and their battery performance is significantly impacted by redox-active molecules and ion-exchange membranes(IEMs).Here,representative anolytes and catholytes engineered for use in pH-neutral AORFBs are outlined and summarized,as well as their side reactions that cause irreversible battery capacity fading.In addition,the recent achievements of IEMs for pH-neutral AORFBs are discussed,with a focus on the construction and tuning of ion transport channels.Finally,the critical challenges and potential research opportunities for developing practically relevant pH-neutral AORFBs are presented.
文摘Railway terminal is an important part of railway network. Transport organization of railway terminal is the key of the railway transport organization. Moreover, the organization of transport work is based on the organization of wagon flows in the railway terminal. Because of the great amounts of equipment and a large number of train operations, the study on railway terminal transport organization is mostly focused on a marshalling station in railway terminal or a part of it. Systematic study taking railway terminal as a whole is very few. In this paper, the organization of wagon flows in a railway terminal is analyzed and a wagon flow model in a railway terminal is established. The main principles of organization of local trains are also presented.
基金jointly supported by the Guangdong Major Project of Basic and Applied Basic Research (2023B0303000002)National Natural Science Foundation of China (22178126,22325802,U22A20417,22208110)+3 种基金Guangdong Basic and Applied Basic Research Foundation (2023B1515120005)Science and Technology Program of Guangzhou (2023B03J1281,2023A04J1357)China Postdoctoral Science Foundation (2023T160223)the State Key Laboratory of Pulp and Paper Engineering (2023ZD03)。
文摘Viologens known as a kind of promising negolyte materials for aqueous organic redox flow batteries,face a critical stability challenge due to the S_N2 nucleophilic attack by hydroxide ions(OH-)during the battery cycling.In this work,a N-cyclic quaternary ammonium-grafted viologen molecule,viz.1,1'-bis(4,4'-dime thylpiperidiniumyl)-4,4'-bipyridinium tetrachloride((DBPPy)Cl_(4)),is developed by the molecular engineering strategy.The obtained(DBPPy)Cl_(4) molecule shows a decent solubility of 1.84 M and a redox potential of-0.52 V vs.Ag/AgCl,Experimental and theoretical results reveal that the grafted N-cyclic quaternary ammonium groups act as the steric hindrance to prevent nucleophilic attack by OH~-,increasing the alkali resistance of the electroactive molecule.The symmetrical battery with 0.50 M(DBPPy)Cl4shows negligible decay during the 13-day cycling test.As demonstration,the flow battery utilizing 1.0 M(DBPPy)Cl_(4) as the negolyte and 1-(1-oxyl-2,2',6,6'-tetramethylpiperidin-4-yl)-1'-(3-(trimethylammonio)propyl)-4,4'-bipyridinium trichloride as the posolyte exhibits a high capacity retention rate of 99.99%per cycle at 60 mA cm^(-2).
基金Supported by the Key Program of the National Natural Science Foundation of China under Grant No 61334009the National High Technology Research and Development Program of China under Grant No 2014AA032604
文摘CaN nanorods are successfully fabricated by adjusting the flow rate ratio of hydrogen （H2）/nitrogen （N2） and growth temperature of the selective area growth （SAG） method with metal organic chemical vapor deposition （MOCVD）. The SAG template is obtained by nanospherical-lens photolithography. It is found that increasing the flow rate of 1-12 will change the CaN crystal shape from pyramid to vertical rod, while increasing the growth temperature will reduce the diameters of GaN rods to nanometer scale. Finally the CaN nanorods with smooth lateral surface and relatively good quality are obtained under the condition that the H2：N2 ratio is 1：1 and the growth temperature is 1030℃. The good crystal quality and orientation of GaN nanorods are confirmed by high resolution transmission electron microscopy. The cathodoluminescence spectrum suggests that the crystal and optical quality is also improved with increasing the temperature.
文摘The entropy balance equation that describes the entropy budget of atmospheric systems is derived from the Gibbs relation.The distribution of the entropy flows of a west-Pacific typhoon and a Bengal-Bay cyclone is calculated and thus the dissipativity of the atmospheric systems is revealed.
文摘in this paper, a general integer prosramming model is set up, and its solution ispresented to optimize the organization of wagon flows and the determination ofthe train running route as well as division of shuntins work among stations in ahub. As application example is put forword, with some conclusions reached.
基金supported by grants from the National Natural Science Foundation of China(No.21875181,22209130,and 22279100)the Natural Science Basic Research Program of Shaanxi(No.2019JLP-13)the China Postdoctoral Science Foundation(No.2022M722524)。
文摘Five-membered pyrroline nitroxides with high-potential is fascinating as catholyte for aqueous organic redox flow batteries(AORFBs),however,it suffers from a primary deficiency of insufficient stability due to ring-opening side reaction.Herein we report a spatial structure regulation strategy by host-guest chemistry,encapsulating 3-carbamoyl-2,2,5,5-tetramethylpyrroline-1-oxyl(CPL)into hydrosoluble cyclodextrins(CDs)with an inclusion structure of N–O⋅head towards cavity bottom,to boost the solubility and cyclability of pyrroline nitroxides significantly.The armor-clad CPL(CPL⊂HP-β-CD)catholyte in 0.05–0.5 M presents a battery capacity fade rate as low as 0.002%/cycle(0.233%/day)compared to the sole CPL in 0.05 M(0.039%/cycle or 5.23%/day)over 500 cycles in assembled AORFBs.The optimized reclining spatial structure with N–O⋅head towards CD cavity bottom effectively inhibits the attack of Lewis base species on the hydrogen abstraction site in pyrroline ring,and thus avoids the ring-opening side reaction of pyrroline nitroxides.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(21925804,21935003)CASDOE Collaborative Project(121421KYSB20170032)+1 种基金CAS Engineering Laboratory for Electrochemical Energy Storage,Liaoning Revitalization Talents Program(XLYC1802050)China and DICP funding,China(ZZBS201707)。
文摘Aqueous organic flow batteries have attracted dramatic attention for stationary energy storage due to their resource sustainability and low cost. However, the current reported systems can normally be operated stably under a nitrogen or argon atmosphere due to their poor stability. Herein a stable airinsensitive biphenol derivative cathode, 3,30,5,50-tetramethylaminemethylene-4,40-biphenol(TABP), with high solubility(>1.5 mol L^(-1)) and redox potential(0.91 V vs. SHE) is designed and synthesized by a scalable one-step method. Paring with silicotungstic acid(SWO), an SWO/TABP flow battery shows a stable performance of zero capacity decay over 900 cycles under the air atmosphere. Further, an SWO/TABP flow battery manifests a high rate performance with an energy efficiency of 85% at a current density of60 m A cm^(-2) and a very high volumetric capacity of more than 47 Ah L^(-1). This work provides a new and practical option for next-generation practical large-scale energy storage.
基金This work was fully supported by the National Natural Science Foundation of China(No.52211530034)the foundation of China University of Petroleum,Beijing(Nos.2462020YXZZ018 and 2462023XKBH005)the foundation of Beijing National Science Foundation(No.3222018).
文摘With the deployment of renewable energy and the increasing demand for power grid modernization,redox flow battery has attracted a lot of research interest in recent years.Among the available energy storage technologies,the redox flow battery is considered the most promising candidate battery due to its unlimited capacity,design flexibility,and safety.In this review,we summarize the latest progress and improvement strategies of common inorganic redox flow batteries,such as vanadium redox flow batteries,iron-chromium redox flow batteries,and zinc-based redox flow batteries,including electrolyte,membrane,electrode,structure design,etc.In addition,we introduce the latest progress in aqueous and non-aqueous organic redox flow batteries.We also focus on the modification mechanism,optimization design,improvement strategy,and modeling method of the redox flow battery reaction.Finally,this review presents a brief summary,challenges,and perspectives of the redox flow battery.
基金supported by the Natural Science Foundation of China(grant nos.22175138 and 21875180)the National Key Research and Development Program of China(grant no.2021YFB3200700)+4 种基金the Key Research and Development Program of Shaanxi(grant no.2021GXLH-Z023)the Independent Innovation Capability Improvement Project of Xi’an Jiaotong University(grant no.PY3A066)the Fundamental Research Funds for the Central Universities(grant no.xhj032021008-03)the Regional Innovation Capability Guidance Program of Shaanxi Province the Fundamental(grant no.2022QFY08-01)the Research Funds for the Central Universities(grant no.xzy022022001).
文摘Two-electron neutral aqueous organic redox flow batteries(AORFBs)hold more promising applications in the power grid than one-electron batteries because of their higher capacity.However,their development is strongly limited by the structural instability of the highly reduced species.By combining the extendedπ-conjugation structure of the anolytes and the enhanced aromaticity of the highly reduced species,we reported a series of highly conjugated and inexpensive arylene diimide derivatives(NDI,PDI,and TPDI)as novel two-electron storage anolyte materials for ultrastable AORFBs.Matched with(ferrocenylmethyl)trimethylammonium chloride(FcNCl)as catholyte,arylene diimide derivative-based AORFBs showed the highest stability in two-electron AORFBs to date.The NDI/FcNCl-based AORFB delivered 98.44%capacity retention at 40 mA cm^(−2)for 350 cycles;TPDI/FcNCl-based AORFB also showed remarkable stability with 97.22%capacity retention at 20 mA cm^(−2)over 200 cycles.This finding lays the theoretical foundation and offers a reference for improving the stability of two-electron AORFBs.
基金supported by the World Class University Program (Case Ⅲ) through the National Research Foundation of Koreafunded by the Ministry of Education, Science and Technology (R33-10046)the Fundamental R&D Program for Technology of World Premier Materials funded by the Ministry of Knowledge Economy, Korea
文摘Fouling behavior along the length of membrane module was systematically investigated by performing simple modeling and lab-scale experiments of forward osmosis （FO） membrane process. The flux distribution model developed in this study showed a good agreement with experimental results, validating the robustness of the model. This model demonstrated, as expected, that the permeate flux decreased along the membrane channel due to decreasing osmotic pressure differential across the FO membrane. A series of fouling experiments were conducted under the draw and feed solutions at various recoveries simulated by the model. The simulated fouling experiments revealed that higher organic （alginate） fouling and thus more flux decline were observed at the last section of a membrane channel, as foulants in feed solution became more concentrated. Furthermore, the water flux in FO process declined more severely as the recovery increased due to more foulants transported to membrane surface with elevated solute concentrations at higher recovery, which created favorable solution environments for organic adsorption. The fouling reversibility also decreased at the last section of the membrane channel, suggesting that fouling distribution on FO membrane along the module should be carefully examined to improve overall cleaning efficiency. Lastly, it was found that such fouling distribution observed with co-current flow operation became less pronounced in counter- current flow operation of FO membrane process.
