Shunt currents in vanadium flow batteries: Measurement, modelling and implications for efficiency

Fink, Holger; Remy, M.

doi:10.1016/j.jpowsour.2015.03.057

Cited by 37 publications

(16 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 7a shows the shunt currents within the ports and manifold as a function of position within the stack. These current magnitudes and trends are similar to past work [78,82]. The edge conditions force the manifold current to match the port current, and this is directly observable at cell N for each stack size.…”

Section: System Performancesupporting

confidence: 80%

“…Each of these models leverage some prior developments from Newman and Tiedemann to describe the porous electrode [74,75]. In addition, modeling efforts have been extended beyond the individual component or cell level to stack systems several times [24,25,[76][77][78][79][80][81][82], but each report employs different empirical, inaccessible descriptors of performance-driving parameters (e.g., mass-transfer correlations). Thus, although multiple models exist, they are generally difficult to use, incorporating an overwhelming number of parameters, the selection of which is always subjective even when well-informed.…”

Section: Introductionmentioning

confidence: 99%

“…The tanks are modeled as reservoirs of a fixed volume with fast homogeneous reactions reducing the solution condition to a combination of two vanadium oxidation states at any given time. To produce a full system model of the VRFB, these component models are coupled to cells with equivalent properties through a circuit network representing shunt current pathways [82,86]. Although the primary objective of this manuscript is the generation of a broadly useful modeling framework for the community, we also explore the sensitivity of predicted system performance to key parameters, such as electrolyte flow rate and the number of cells in a stack, to both illustrate their influence and validate the model results against existing literature.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A One-Dimensional Stack Model for Redox Flow Battery Analysis and Operation

Barton

Brushett

2019

Batteries

View full text Add to dashboard Cite

Current redox flow battery (RFB) stack models are not particularly conducive to accurate yet high-throughput studies of stack operation and design. To facilitate system-level analysis, we have developed a one-dimensional RFB stack model through the combination of a one-dimensional Newman-type cell model and a resistor-network to evaluate contributions from shunt currents within the stack. Inclusion of hydraulic losses and membrane crossover enables constrained optimization of system performance and allows users to make recommendations for operating flow rate, current densities, and cell design given a subset of electrolyte and electrode properties. Over the range of experimental conditions explored, shunt current losses remain small, but mass-transfer losses quickly become prohibitive at high current densities. Attempting to offset mass-transfer losses with high flow rates reduces system efficiency due to the increase in pressure drop through the porous electrode. The development of this stack model application, along with the availability of the source MATLAB code, allows for facile approximation of the upper limits of performance with limited empiricism. This work primarily presents a readily adaptable tool to enable researchers to perform either front-end performance estimates based on fundamental material properties or to benchmark their experimental results.

show abstract

Section: System Performancesupporting

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A One-Dimensional Stack Model for Redox Flow Battery Analysis and Operation

Barton

Brushett

2019

Batteries

View full text Add to dashboard Cite

show abstract

“…This faster decrease of OCV is consistent with the assumption that ionic shunt current through the feed/exit lines of the electrolytes should be responsible for the OCV decrease. A similar influence of shunt currents through parallel feed/exit lines of the electrolytes is well known from redox flow batteries [10][11][12]. In stacks with 10 and more cells, OCV shows an accelerated decline to about 4 V after a certain period of low decline, which becomes shorter with increasing cell number.…”

Section: Self-discharge At Ocvsupporting

confidence: 55%

Acid-Base Flow Battery, Based on Reverse Electrodialysis with Bi-Polar Membranes: Stack Experiments

et al. 2020

View full text Add to dashboard Cite

Neutralization of acid and base to produce electricity in the process of reverse electrodialysis with bipolar membranes (REDBP) presents an interesting but until now fairly overlooked flow battery concept. Previously, we presented single-cell experiments, which explain the principle and discuss the potential of this process. In this contribution, we discuss experiments with REDBP stacks at lab scale, consisting of 5 to 20 repeating cell units. They demonstrate that the single-cell results can be extrapolated to respective stacks, although additional losses have to be considered. As in other flow battery stacks, losses by shunt currents through the parallel electrolyte feed/exit lines increases with the number of connected cell units, whereas the relative importance of electrode losses decreases with increasing cell number. Experimental results are presented with 1 mole L−1 acid (HCl) and base (NaOH) for open circuit as well as for charge and discharge with up to 18 mA/cm2 current density. Measures to further increase the efficiency of this novel flow battery concept are discussed.

show abstract

“…Therefore, it is important how these conditions can be made an improvement to restrain the degradation of the electrodes. 1,2,[5][6][7][8][9][10][11][12][13][14] The reverse current is also a serious problem with brine electrolysis of the chlor-alkali process. The major driving force for the reverse current is the active chlorine oxidant of the anolyte, such as OCl ¹ , and the reductant such as H 2 adsorbed on the cathode.…”

Section: Introductionmentioning

confidence: 99%

Dependence of the Reverse Current on the Surface of Electrode Placed on a Bipolar Plate in an Alkaline Water Electrolyzer

et al. 2018

View full text Add to dashboard Cite

The behavior of the leak and reverse currents in a bipolar-type alkaline water electrolyzer has been investigated using a bipolar-type electrolyzer which consists of two cells. The electrodes were nickel mesh, which are the conventional electrodes for alkaline water electrolyzers. The leak circuit could be expressed by a simple equation and a simple equivalent circuit for the cell performance and ionic resistance of the manifolds. The electrolyte was replaced by a gas-free electrolyte after electrolysis to classify the influence of the reverse current into the gas reaction and electrode active material. As a result, the dominant driving force of the reverse current was the active nickel-based materials on the Ni electrode. The redox couples on the electrode surface during the reverse current were estimated based on the measured cell voltages and redox potentials on a nickel electrode. The final potentials of both sides on the bipolar plate for the replacement conditions were higher than those for the non-replacement condition, because the hydrogen of the reductant was removed from the cathode electrolyte, and the balance of the reductant and oxidant would change to the oxidation side.

show abstract

Shunt currents in vanadium flow batteries: Measurement, modelling and implications for efficiency

Cited by 37 publications

References 5 publications

A One-Dimensional Stack Model for Redox Flow Battery Analysis and Operation

A One-Dimensional Stack Model for Redox Flow Battery Analysis and Operation

Acid-Base Flow Battery, Based on Reverse Electrodialysis with Bi-Polar Membranes: Stack Experiments

Dependence of the Reverse Current on the Surface of Electrode Placed on a Bipolar Plate in an Alkaline Water Electrolyzer

Contact Info

Product

Resources

About