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
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
The composition of electrolyte affects to a great extent the electrochemical performance of vanadium redox flow batteries(VRB).The effects of Cr3+ concentration in the anolyte on the electrode process of V(V)/V(IV) co...The composition of electrolyte affects to a great extent the electrochemical performance of vanadium redox flow batteries(VRB).The effects of Cr3+ concentration in the anolyte on the electrode process of V(V)/V(IV) couple have been investigated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).It was found that Cr3+ causes no side reactions,but affects the electrochemical performance of V(V)/V(IV) redox reaction,including the reaction activity,the reversibility of electrode reaction,the diffusivity of vanadium ions,the interface film impedance,and the electrode reaction impedance.The experimental results show that Cr3+ within a certain concentration range can improve the reversibility of electrode reaction and the diffusion of vanadium ions.With the Cr3+ concentration increasing from 0 to 0.30 g L-1,the reversibility of V(V)/V(IV) reaction increases,while the diffusion resistance decreases.Correspondingly,the diffusion coefficient of vanadium ions increases from(5.48-6.77) × 10-7 to(6.82-8.44) × 10-7 cm2 s-1,an increase of ～24%.However,the diffusion resistance increases and the diffusion coefficient decreases when Cr3+ concentration is over 0.30 g L-1,while the impedances of the interface,the film as well as the charge transfer increase continuously.As a result,Cr3+ with a certain concentration improves the diffusion and mass transfer process,but the resistances of the film,the interface,and the charge transfer rise.Furthermore,Cr3+ concentration of no more than 0.10 g L-1 has few effect on the electrode reaction process,and that of no more than 0.30 g L-1 is favorable to the diffusion of vanadium ions.展开更多
A major limitation associated with fermenta- tive hydrogen production is the low substrate conversion efficiency. This limitation can be overcome by integrating the process with a microbial fuel cell （MFC） which con...A major limitation associated with fermenta- tive hydrogen production is the low substrate conversion efficiency. This limitation can be overcome by integrating the process with a microbial fuel cell （MFC） which converts the residual energy of the substrate to electricity. Studies were carried out to check the feasibility of this integration. Biohydrogen was produced from the fermen- tation of cane molasses in both batch and continuous modes. A maximum yield of about 8.23 mol Hz/kg CODremoved was observed in the batch process compared to 11.6 mol Hz/kg CODremoved in the continuous process. The spent fermentation media was then used as a substrate in an MFC for electricity generation. The MFC parameters such as the initial anolyte pH, the substrate concentration and the effect ofpre-treatment were studied and optimized to maximize coulombic efficiency. Reductions in COD and total carbohydrates were about 85% and 88% respectively. A power output of 3.02 W/m3 was obtained with an anolyte pH of 7.5 using alkali pre-treated spent media. The results show that integrating a MFC with dark fermentation is a promising way to utilize the substrate energy.展开更多
The corrosion pathways in AA2024-T3, AA5083-O and AA6082-T6 alloys have been investigated. The objective of the investigation is to further the understanding of the complex localised corrosion mechanism in aluminium a...The corrosion pathways in AA2024-T3, AA5083-O and AA6082-T6 alloys have been investigated. The objective of the investigation is to further the understanding of the complex localised corrosion mechanism in aluminium alloys. The investigation was carried out by examining the corroded surfaces of the alloys after potentiodynamic polarization tests in a 3.5% NaCl solution with the aid of a scanning electron microscope, and by analysing the flow of anolyte solution using the scanning vibrating electrode technique. The results revealed that the overall corrosion pathways in the alloys are distinctively different and are influenced by the flow of anolyte solution. Also revealed, was the fact that corrosion propagates in two ways （particularly in the AA5083-O and AA6082-T6 alloys）： an overall pathway in the corrosion front （filiform-like pathway in the AA5083 alloy and organized linear pathways in AA6082 alloy）; and the crystallographic channelling along the （100） directions. These are dependent on the grain distinct features of the AA5083-O and AA6082-T6 alloys and are not influenced by the presence of coarse second phase particles in these alloys, compared with the AA2024-T3 alloy, where the corrosion pathways are more dependent on the presence of second phase particles and grain boundary character.展开更多
The electrochemical behavior of the V( Ⅳ )/V( Ⅴ ) redox couple at a glassy carbon electrode was investigated. Cyclic voltammetry(CV) results indicated that electrode process of the V( Ⅳ )/V( Ⅴ ) couple was electro...The electrochemical behavior of the V( Ⅳ )/V( Ⅴ ) redox couple at a glassy carbon electrode was investigated. Cyclic voltammetry(CV) results indicated that electrode process of the V( Ⅳ )/V( Ⅴ ) couple was electrochemically quasi-reversible with a rate constant of 8 × 10^-4 cm/S . Increasing concentration of sulfuric acid was electrochemically favourable for the V( Ⅳ )/V( Ⅴ )couple while elevated temperature was unfavourable for this system. Constant-current electrolysis results showed that current efficiency of more than 95 % could be achieved, which indicated that the V( Ⅳ )/V( Ⅴ ) couple had excellent electrolytic performance and was suitable for the application as the anolyte of redox flow batteries.展开更多
In present research, a novel extractant system (D2EHPA + naphthenic acid + pyridine- ester) was used to purify cobalt anolyte and a simulated industrial production were carried out. This novel extraction system can ex...In present research, a novel extractant system (D2EHPA + naphthenic acid + pyridine- ester) was used to purify cobalt anolyte and a simulated industrial production were carried out. This novel extraction system can extract Cu and/or Ni against Co from chloride medium solutions at pH range of 2.5-4.5. About 2g/l nickel and 0.2g/l copper were removed from the cobalt chloride anolyte containing about 100g/l cobalt and 200g/l chloride ions respectively, the raffinate contains nickel and copper less than 0.03g/l and 0.0003g/l respectively and can be used to electrolyze high-purity cobalt. About 5.5t cobalt anolyte was purified in the simulation industrial experiment and kilogram quantities of cobalt of 99.98% purity and about 95% recovery have been produced.展开更多
Non-aqueous redox flow batteries, because of larger operating voltage, have attracted considerable at- tention for high-density energy storage applications. However, the study of the anolyte is rather limited compared...Non-aqueous redox flow batteries, because of larger operating voltage, have attracted considerable at- tention for high-density energy storage applications. However, the study of the anolyte is rather limited compared with the catholyte due to the labile properties of redox mediators at low potentials. Here, we report a new strategy that exploits high concentration organic lithium metal solution as a robust and energetic anolyte. The solution formed by dissolving metallic lithium with biphenyl （BP） in tetraethylene glycol dimethyl ether （TEGDME） presents a redox potential of 0.39V versus Li/Li＋, and a concentration up to 2 M. When coupled with a redox-targeted LiFePO4 catholyte system, the constructed redox flow lithium battery full cell delivers a ceil voltage of 3.0V and presents reasonably good cycling performance.展开更多
Worldwide epidemiological reports assert that drinking water is a source for infections and Legionella control represents a critical issue in healthcare settings. Chemical disinfections of water networks are control m...Worldwide epidemiological reports assert that drinking water is a source for infections and Legionella control represents a critical issue in healthcare settings. Chemical disinfections of water networks are control measures that need to be fine-tuned to obtain satisfactory results in large buildings over prolonged time periods. Aim of study is the evaluation of the effect of anolyte and chlorine dioxide, applied in two different hot water networks of a nursing home to manage Legionella risk. Nursing home has two buildings (A and B), with the same point of aqueduct water entrance. From June 2016, following a shock chlorination, the continuous disinfections with chlorine dioxide and anolyte were applied in hot networks of building A and B, respectively. Hot water was sampled at the central heating system and at two points of use for Legionella research, while chemical tests of manganese (Mn), iron (Fe), zinc (Zn) and trihalomethanes compounds (THM) were implemented to evaluate the disinfection by-products presence. Before chlorination Legionella pneumophila sg1 was recovered with a mean count of 2.4 × 104 CFU/L, while chemical compounds concentrations were within the law limits (Directive 98/83/EC). Then the disinfections Legionella was not recovered in both hot water plants. After the disinfection with chlorine dioxide (from June 2016 to May 2018), a statistically significant increase of iron, zinc and THM concentrations was detected in building A (p = 0.012;p = 0.004;p = 0.008). Both disinfectants appear effective against Legionella spp. growth in water network, but anolyte ensures a lower disinfection by-products release.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.
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 Youth Foundation of Sichuan University (07046)PanGang Group Panzhihua Iron & Steel Research Institute (11H0762)
文摘The composition of electrolyte affects to a great extent the electrochemical performance of vanadium redox flow batteries(VRB).The effects of Cr3+ concentration in the anolyte on the electrode process of V(V)/V(IV) couple have been investigated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).It was found that Cr3+ causes no side reactions,but affects the electrochemical performance of V(V)/V(IV) redox reaction,including the reaction activity,the reversibility of electrode reaction,the diffusivity of vanadium ions,the interface film impedance,and the electrode reaction impedance.The experimental results show that Cr3+ within a certain concentration range can improve the reversibility of electrode reaction and the diffusion of vanadium ions.With the Cr3+ concentration increasing from 0 to 0.30 g L-1,the reversibility of V(V)/V(IV) reaction increases,while the diffusion resistance decreases.Correspondingly,the diffusion coefficient of vanadium ions increases from(5.48-6.77) × 10-7 to(6.82-8.44) × 10-7 cm2 s-1,an increase of ～24%.However,the diffusion resistance increases and the diffusion coefficient decreases when Cr3+ concentration is over 0.30 g L-1,while the impedances of the interface,the film as well as the charge transfer increase continuously.As a result,Cr3+ with a certain concentration improves the diffusion and mass transfer process,but the resistances of the film,the interface,and the charge transfer rise.Furthermore,Cr3+ concentration of no more than 0.10 g L-1 has few effect on the electrode reaction process,and that of no more than 0.30 g L-1 is favorable to the diffusion of vanadium ions.
文摘A major limitation associated with fermenta- tive hydrogen production is the low substrate conversion efficiency. This limitation can be overcome by integrating the process with a microbial fuel cell （MFC） which converts the residual energy of the substrate to electricity. Studies were carried out to check the feasibility of this integration. Biohydrogen was produced from the fermen- tation of cane molasses in both batch and continuous modes. A maximum yield of about 8.23 mol Hz/kg CODremoved was observed in the batch process compared to 11.6 mol Hz/kg CODremoved in the continuous process. The spent fermentation media was then used as a substrate in an MFC for electricity generation. The MFC parameters such as the initial anolyte pH, the substrate concentration and the effect ofpre-treatment were studied and optimized to maximize coulombic efficiency. Reductions in COD and total carbohydrates were about 85% and 88% respectively. A power output of 3.02 W/m3 was obtained with an anolyte pH of 7.5 using alkali pre-treated spent media. The results show that integrating a MFC with dark fermentation is a promising way to utilize the substrate energy.
基金EPSRC for financial support through the LATEST2 Programme grant (EP/H020047/1)
文摘The corrosion pathways in AA2024-T3, AA5083-O and AA6082-T6 alloys have been investigated. The objective of the investigation is to further the understanding of the complex localised corrosion mechanism in aluminium alloys. The investigation was carried out by examining the corroded surfaces of the alloys after potentiodynamic polarization tests in a 3.5% NaCl solution with the aid of a scanning electron microscope, and by analysing the flow of anolyte solution using the scanning vibrating electrode technique. The results revealed that the overall corrosion pathways in the alloys are distinctively different and are influenced by the flow of anolyte solution. Also revealed, was the fact that corrosion propagates in two ways （particularly in the AA5083-O and AA6082-T6 alloys）： an overall pathway in the corrosion front （filiform-like pathway in the AA5083 alloy and organized linear pathways in AA6082 alloy）; and the crystallographic channelling along the （100） directions. These are dependent on the grain distinct features of the AA5083-O and AA6082-T6 alloys and are not influenced by the presence of coarse second phase particles in these alloys, compared with the AA2024-T3 alloy, where the corrosion pathways are more dependent on the presence of second phase particles and grain boundary character.
文摘The electrochemical behavior of the V( Ⅳ )/V( Ⅴ ) redox couple at a glassy carbon electrode was investigated. Cyclic voltammetry(CV) results indicated that electrode process of the V( Ⅳ )/V( Ⅴ ) couple was electrochemically quasi-reversible with a rate constant of 8 × 10^-4 cm/S . Increasing concentration of sulfuric acid was electrochemically favourable for the V( Ⅳ )/V( Ⅴ )couple while elevated temperature was unfavourable for this system. Constant-current electrolysis results showed that current efficiency of more than 95 % could be achieved, which indicated that the V( Ⅳ )/V( Ⅴ ) couple had excellent electrolytic performance and was suitable for the application as the anolyte of redox flow batteries.
文摘In present research, a novel extractant system (D2EHPA + naphthenic acid + pyridine- ester) was used to purify cobalt anolyte and a simulated industrial production were carried out. This novel extraction system can extract Cu and/or Ni against Co from chloride medium solutions at pH range of 2.5-4.5. About 2g/l nickel and 0.2g/l copper were removed from the cobalt chloride anolyte containing about 100g/l cobalt and 200g/l chloride ions respectively, the raffinate contains nickel and copper less than 0.03g/l and 0.0003g/l respectively and can be used to electrolyze high-purity cobalt. About 5.5t cobalt anolyte was purified in the simulation industrial experiment and kilogram quantities of cobalt of 99.98% purity and about 95% recovery have been produced.
基金financial support by the Energy Market Authority, Singapore under its Energy Innovation Research Programme-Energy Storage (NRF2015EWT-EIRP002)
文摘Non-aqueous redox flow batteries, because of larger operating voltage, have attracted considerable at- tention for high-density energy storage applications. However, the study of the anolyte is rather limited compared with the catholyte due to the labile properties of redox mediators at low potentials. Here, we report a new strategy that exploits high concentration organic lithium metal solution as a robust and energetic anolyte. The solution formed by dissolving metallic lithium with biphenyl （BP） in tetraethylene glycol dimethyl ether （TEGDME） presents a redox potential of 0.39V versus Li/Li＋, and a concentration up to 2 M. When coupled with a redox-targeted LiFePO4 catholyte system, the constructed redox flow lithium battery full cell delivers a ceil voltage of 3.0V and presents reasonably good cycling performance.
文摘Worldwide epidemiological reports assert that drinking water is a source for infections and Legionella control represents a critical issue in healthcare settings. Chemical disinfections of water networks are control measures that need to be fine-tuned to obtain satisfactory results in large buildings over prolonged time periods. Aim of study is the evaluation of the effect of anolyte and chlorine dioxide, applied in two different hot water networks of a nursing home to manage Legionella risk. Nursing home has two buildings (A and B), with the same point of aqueduct water entrance. From June 2016, following a shock chlorination, the continuous disinfections with chlorine dioxide and anolyte were applied in hot networks of building A and B, respectively. Hot water was sampled at the central heating system and at two points of use for Legionella research, while chemical tests of manganese (Mn), iron (Fe), zinc (Zn) and trihalomethanes compounds (THM) were implemented to evaluate the disinfection by-products presence. Before chlorination Legionella pneumophila sg1 was recovered with a mean count of 2.4 × 104 CFU/L, while chemical compounds concentrations were within the law limits (Directive 98/83/EC). Then the disinfections Legionella was not recovered in both hot water plants. After the disinfection with chlorine dioxide (from June 2016 to May 2018), a statistically significant increase of iron, zinc and THM concentrations was detected in building A (p = 0.012;p = 0.004;p = 0.008). Both disinfectants appear effective against Legionella spp. growth in water network, but anolyte ensures a lower disinfection by-products release.
