A5087443408- Advanced battery technologies research
- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Supercapacitor Materials and Fabrication
- Advanced Battery Technologies Research
- Catalysis and Oxidation Reactions
- Catalytic Processes in Materials Science
- Membrane-based Ion Separation Techniques
- Advanced Battery Materials and Technologies
- Transition Metal Oxide Nanomaterials
- Gas Sensing Nanomaterials and Sensors
- Advancements in Battery Materials
- TiO2 Photocatalysis and Solar Cells
- Perovskite Materials and Applications
- Advancements in Solid Oxide Fuel Cells
- Electrochemical Analysis and Applications
- Extraction and Separation Processes
- Transportation Planning and Optimization
- Hybrid Renewable Energy Systems
- Traffic control and management
- CO2 Reduction Techniques and Catalysts
- Electronic and Structural Properties of Oxides
- Traffic Prediction and Management Techniques
Harvard University
2020-2023
Oak Ridge National Laboratory
2015-2021
Harvard University Press
2021
University of Shanghai for Science and Technology
2019
University of Tennessee at Knoxville
2011-2018
Oak Ridge Associated Universities
2016
The sulfuric acid, vanadyl (VO2+) and water equilibrium in Nafion membranes contacted by solutions containing these species is described. Of particular interest the influence of composition on ionic transport behavior membrane separators for an all-vanadium redox flow battery (VRFB). Ex-situ conductivity measurements were conducted 117 equilibrated electrolyte varying acid ion concentrations. Electrolyte imbibed analyzed experimental protocol including titration, ICP-OES weight analysis....
We describe methods for assessment of the state charge (SOC) vanadium redox flow batteries during operation using UV-vis spectrophotometry and full cell OCV measurements. The absorbance negative electrolyte solution at 433 nm, 600 nm 750 is linear in SOC > 0.2. positive does not display a relationship with SOC, which we attribute to formation strongly absorbing third species. An analysis excess suggests that complex 1:1 stoichiometry formed by VO2+ VO2+. Full-cell measurements were found...
Water-soluble anthraquinones (AQs) hold great promise serving as redox-active species in aqueous organic flow batteries. Systematic investigations into how the properties of redox molecules depend on water-solubilizing groups (WSGs) and way which they are bound to core are, however, still lacking. We introduce WSGs linked anthraquinone by C═C bonds via a cross-coupling reaction convert C–C through hydrogenation. The connected (un)branched chains with (un)saturated bonds. investigate...
An anthraquinone featuring a chiral carboxylate-capped methyl-branched side chain with an ether linkage, 2,2′-((9,10-dioxo-9,10-dihydroanthracene-2,6-diyl)bis(oxy))dipropionic acid (2,6-D2PEAQ), was synthesized and evaluated for use in aqueous redox flow batteries. It found to have extraordinary solubility of 2 M (4 electrons), corresponding theoretical volumetric capacity 107.2 Ah/L the negative electrolyte, which is 10 times that its unbranched counterpart. The 2,6-D2PEAQ molecule...
Redox flow batteries (RFBs) can achieve long lifetimes and high performance when employing highly selective conductive membranes. Neutral alkaline RFBs suffer from higher resistances due to lower cation conductivity, compared acidic utilizing proton transport. We report the use of a sulfonated Diels-Alder poly(phenylene) membrane that exhibits low stable potassium area specific resistance efficiency RFB cycling relative Nafion, as well undetectable ferricyanide crossover. An (pH 12) organic...
The proton exchange membrane is widely used in vanadium redox flow battery as electrolyte separator and conductors. In this paper, two commercial membranes, Nafion 3Mion, have been investigated. High frequency resistance water acid uptake of the PEMs are measured after equilibration sulfuric different concentrations. conductivity correlated to content activity inside membrane. membranes equilibrated a vanadium/sulfuric solution was also compared internal an operating with same comparison...
Nanoporous membrane templates were prepared from self-assembled block copolymers composed of polysulfone and degradable polylactide blocks. The pore surface in the template was modified with sulfonic acid groups. membranes evaluated a vanadium redox battery.
Sulfonated Diels-Alder poly(phenylene) (SDAPP) membranes were synthesized and characterized as potential electrolyte separators for vanadium redox flow batteries. The SDAPP studied had ion exchange capacities of 1.4, 1.8 2.3 meq/g. Transmission electron microscopy imaging shows that the ionic domains in are roughly 0.5 nm dimension, while Nafion has a hydrophilic phase width around 5 nm. sulfuric acid uptake by was higher than Nafion, but materials similar water from solutions various...
In this work, we report on the performance of Diels Alder poly(phenylene) membranes in vanadium redox flow batteries. The were functionalized with quaternary ammonium groups to form an anion exchange membrane (QDAPP) and sulfonic acid a cation (SDAPP). Both classes showed similar conductivities battery environment, suggesting that ion conduction mechanism material is not strongly affected by moieties along polymer backbone. resistance permeation QDAPP was improved relative SDAPP, further...
Vanadium diffusion through Nafion membranes was investigated under conditions applicable to vanadium redox flow batteries (VRFBs). In this case, we examine the effects of interdiffusion VO2+ with protons, V3+ and by a 'cross-diffusion' experiment in which other ion diffuse from opposite sides membrane. concentrations reservoirs designed solution over both membrane were monitored using UV/vis EPR spectroscopies. The permeability each determined coefficients measurements uptake is highest when...
Sodium-based batteries are promising for grid-storage applications because of significantly lower cost compared to lithium-based systems. The advancement solid-state and redox-flow sodium-ion requires exchange membranes with high conductivity, electrochemical stability, mechanical robustness. This study demonstrates that based on poly(ethylene oxide) (PEO) can meet these requirements. Membranes plasticized tetraethylene glycol dimethyl ether (TEGDME) achieve ionic conductivity. Plasticized...
Sulfonated diels alder poly(phenylene) (SDAPP), alternative aromatic hydrocarbon membranes for vanadium redox flow batteries (VRFBs) are characterized using electron paramagnetic resonance (EPR). Membranes soaked in sulfuric acid and vanadyl sulfate analyzed to determine the membrane environment which ion (VO2+) diffuses membranes. These results compared Nafion 117 In contrast Nafion, VO2+ SDAPP exists two different environments. The of analysis rotational diffusion determined from fits EPR...
We use polarization curves and a dynamic hydrogen reference electrode (DHE) to study the effects of material state charge on all-vanadium redox flow battery (VRB) performance. The current trend in studying these systems is evaluate new materials or designs based voltage, power efficiency metrics. However, such characterization does not allude which processes may be limiting performance dominates loss. At moderate charge, negative dominated cell overpotential at all densities. As increased,...
Electron Spin Resonance (ESR) was used to characterize the effects of vanadyl ion in Nafion 117. The ESR signal a tempone spin probe as qualitative standard compare intensity imbibed membrane with vanadium membrane. Initial measurements crossover were recorded by monitoring concentration increase blank solution flowed on one side battery apparatus simultaneously opposite side.
This paper discusses the influence that location of a bus stop has on traffic flow and passenger satisfaction when they are near to signalised intersection. Traffic is modelled measure delay usage under variety flows signal cycle times. It concludes maximum benefits can be obtained if stops located both prior immediately following
The characterization of perfluorsulfonate and sulfonated block copolymer ion exchange membranes is well established in aqueous systems. While many these have been proved to favorable conductivity stability multiple applications(1,2), similar studies are hardly found for non-aqueous Although some results on system published(3), a complete understanding how behave organic solvents lacking. largest range existing methods mostly dedicated probing In light emerging applications, especially...