Journal article
Pore-scale analysis of effects of electrode morphology and electrolyte flow conditions on performance of vanadium redox flow batteries
Journal of power sources, v 219, pp 223-234
01 Dec 2012
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
A 3D pore-scale transport resolved model is used to study the performance characteristics of a vanadium redox flow battery (VRFB) with various electrode morphologies under different operating conditions. Three electrode structures are reconstructed from X-ray computed tomography (XCT) images of porous carbon felt electrode materials. The local vanadium concentration, overpotential, current density and overall cell voltage for the positive half cell are examined. The results indicate that the cell voltage increases with increasing electrolyte flow rate due to decreasing concentration gradients of vanadium species within the porous electrode. However, the marginal gain in cell voltage diminishes once the concentration field approaches uniformity under convection-dominated mass transport conditions at sufficiently high electrolyte flow rates. The model also predicts that electrode structures with low porosity (high surface area) result in more uniform and lower absolute current density and overpotential fields at the expense of increased pressure drop. Finally, poor cell performance is observed for simulations operated at low electrolyte flow rates and low states of charge due to the fuel starvation (i.e., insufficient amount of reactant in the cell).
► We perform pore-scale simulations for different XCT-reconstructed electrode morphologies. ► We predict cell performance for different flow rates. ► Cell voltage saturates at high flow rates when concentration approaches uniformity. ► Fuel starvation is found to have a negative impact on cell voltage. ► We report statistical distributions of local parameters across the 3D porous electrode.
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Details
- Title
- Pore-scale analysis of effects of electrode morphology and electrolyte flow conditions on performance of vanadium redox flow batteries
- Creators
- Gang Qiu - Complex Fluids and Multiphase Transport Laboratory, Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104, USAC.R Dennison - Electrochemical Energy Systems Laboratory, Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104, USAK.W Knehr - Electrochemical Energy Systems Laboratory, Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104, USAE.C Kumbur - Electrochemical Energy Systems Laboratory, Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104, USAYing Sun - Complex Fluids and Multiphase Transport Laboratory, Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104, USA
- Publication Details
- Journal of power sources, v 219, pp 223-234
- Publisher
- Elsevier
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Mechanical Engineering and Mechanics
- Web of Science ID
- WOS:000309568400032
- Scopus ID
- 2-s2.0-84864774671
- Other Identifier
- 991014878066804721
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InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Chemistry, Physical
- Electrochemistry
- Energy & Fuels
- Materials Science, Multidisciplinary