In-situ characterization of symmetric dual-pass architecture of microfluidic co-laminar flow cells

Ibrahim, Omar; Goulet, Marc‐Antoni; Kjeang, Erik

doi:10.1016/j.electacta.2015.11.081

Cited by 34 publications

(27 citation statements)

References 24 publications

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“…In addition, a couple of new studies built upon the previous work by Salloum et al [105] and Moore et al [106], to assess the possibility for stacking of multiple cells [100], [107]. In all cases, stacks generally exhibited power output nearly proportional to the number of cells, with discrepancies likely due to the shunt current losses [99], [108].…”

Section: Table 1 Major Co-laminar Flow Cell Performance Developmentsmentioning

confidence: 99%

Co-laminar flow cells for electrochemical energy conversion

Goulet

Kjeang

2014

Journal of Power Sources

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103

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A recently developed class of electrochemical cell based on co-laminar flow of reactants through porous electrodes is investigated. New architectures are designed and assessed for fuel recirculation and rechargeable battery operation.Extensive characterization of cells is performed to determine most sources of voltage loss during operation. To this end, a specialized flow cell technique is developed to mitigate mass transport limitations and measure kinetic rates of reaction on flow-through porous electrodes. This technique is used in in conjunction with cyclic voltammetry and electrochemical impedance spectroscopy to evaluate different treatments for enhancing the rates of vanadium redox reactions on carbon paper electrodes. It is determined that surface area enhancements are the most effective way for increasing redox reaction rates and thus a novel in situ flowing deposition method is conceived to achieve this objective at minimal cost. It is demonstrated that flowing deposition of carbon nanotubes can increase the electrochemical surface area of carbon paper by over an order of magnitude. It is also demonstrated that flowing deposition can be achieved dynamically during cell operation, leading to considerably improved kinetics and mass transport properties. To take full advantage of this deposition method, the total ohmic resistance of the cell is considerably reduced through design optimization with reduced channel width, integration of current collectors and reduction of reactant concentration. With electrodes enhanced by dynamic flowing deposition the cell presented in this study demonstrates nearly a fourfold improvement in power density over the baseline design.Producing more than twice the power density of the leading co-laminar flow cell without the use of catalysts or elevated temperatures and pressures, this cell provides a lowcost standard for further research into system scale-up and implementation of co-laminar flow cell technology. More generally, the experimental technique and deposition method developed in this work are expected to find broader use in other fields of electrochemical energy conversion. am also very grateful to my graduate colleagues at SFU and friends in FCRel, with a special mention to Omar in particular, for all the pleasant conversations and good times.I wish there had been more.Last but not least, I'd like to acknowledge all the family and friends I was unable to spend quality time with due to this work. I look forward to seeing you all again.vi Tables Table 1. for their higher specific energy and energy density [6]. For the same reasons, the lower power (< 100 W) market which is driven by portable consumer electronics, is currently 2 dominated by closed cell lithium ion batteries in particular [7]. As these batteries reach their limits and fail to keep up with the energy requirements of modern electronics, micro fuel cells with passively pumped higher energy density liquid reactants such as methanol have been suggested as a potential replacement [8].Regardless...

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Section: Table 1 Major Co-laminar Flow Cell Performance Developmentsmentioning

confidence: 99%

Co-laminar flow cells for electrochemical energy conversion

Goulet

Kjeang

2014

Journal of Power Sources

Self Cite

103

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“…Stock electrolyte (50/50, V 2+ /V 3+ ) in 4-M sulfuric acid solution was recharged to produce V 2+ and VO þ 2 as the anolyte and catholyte, respectively. This pioneer work is chosen for the model validation as it has established a both experimentally and computationally well-defined system of vanadium redox MFC with porous electrodes in conjunction with a series of studies [30][31][32][33][34][35][36] . Consequently, the parameter values needed in the simulation can be derived from previous literatures 29,30,32,35 .…”

Section: Model Validationmentioning

confidence: 99%

Design of a radial vanadium redox microfluidic fuel cell: A new way to break the size limitation

Bei

Liu

et al. 2019

Int J Energy Res

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Summary Microfluidic fuel cell (MFC) suffers from small single cell output power due to the inherent cell size limitation as microscale geometries are prerequisite to prevent reactant crossover between the anode and cathode. To meet the power demand of practical applications, previous works mainly focus on the creating of MFC stacks with multiple cells connected in series, parallel, or mixture of both series and parallel to increase the output power. Yet, low energy efficiency is observed because of the flow distribution nonuniformity and shunt current losses. In this work, a high performance radial vanadium redox MFC is presented to address the size limitation issue by adding a separate layer between the porous electrodes of the conventional plate‐frame MFC. Specific cell characteristics are detailed by mathematical modeling, and parametric studies are performed to evaluate the influences of the geometrical and operational parameters on the cell performance. The results show that this new radial MFC can provide a higher fuel utilization and meanwhile an improved cell performance under a fixed electrode size compared with the conventional plate‐frame MFC. Moreover, the electrode size limitation due to the reactant crossover between the anode and cathode is broken as the influences of the electrode size on the mixing region are greatly reduced. In the case with the electrode size equal to 18 mm × 18 mm, single cell output power of 0.35 mW with a fuel utilization of 53.33% is obtained under the reactant concentration of 2 mol L−1 and flow rate of 300 μL min−1.

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“…This flow rate is chosen in order to minimize influences from mass transport losses on the cell performance, as demonstrated in other works utilizing the same analytical cell. 42 The measurements are performed by the same potentiostat in potentiodynamic mode at a scan rate that is slow enough to match steady state measurements (10 mV/s) from OCP to 0.1 V. The performance is normalized to the active cross sectional area normal to the flow (0.5 × 0.015 cm 2 ). The cell ohmic resistance is measured by EIS performed at OCP using the same potentiostat and same frequency range as in the ex-situ measurements.…”

Section: Methodsmentioning

confidence: 99%

“…The cell design was previously used in other analytical studies and shown to enable high discharge performance and minimal cross over losses. 42 The device is fabricated by UV soft lithography of polydimethylsiloxane (PDMS) (Dow Corning) from an SU-8 (Microchem) photoresist master with 150 μm height then bonded to a glass slide. Rectangular strips of carbon paper (TGPH-060, Toray), with 1 mm width, are heat treated and placed to form both cell electrodes.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of Redox Chemistries for Single-Use Biodegradable Capillary Flow Batteries

Ibrahim

Alday

Sabaté

et al. 2017

J. Electrochem. Soc.

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The rate of battery waste generation is rising dramatically worldwide due to increased use and consumption of electronic devices. A new class of portable and biodegradable capillary flow batteries was recently introduced as a solution for single-use disposable applications. The concept utilizes stored organic redox species and supporting electrolytes inside a dormant capillary flow cell which is activated by the dropwise addition of aqueous liquid. Herein, various organic redox species are systematically evaluated for prospective use in disposable capillary flow cells with regards to their electrochemical characteristics, solubility, storability and biodegradability. Qualitative ex-situ techniques are first applied to assess half-cell solubility, redox potential and kinetics, followed by quantitative in-situ measurements of discharge performance of selected redox chemistries in a microfluidic cell with flow-through porous electrodes. Para-benzoquinone in oxalic acid and either hydroquinone sulfonic acid or ascorbic acid in potassium hydroxide are identified for the positive and negative half-cells, respectively, yielding a maximum discharge power density of 50 mW/cm 2 . A prototype capillary flow battery using the same redox chemistries demonstrates robust cell voltages above 1.0 V and maximum discharge power of 1.9 mW. These results show that practical primary battery performance can be achieved with biodegradable chemistries in a disposable device. The market demand for small-size single-use electronic devices such as portable sensors and diagnostic devices has been rising drastically in recent years. The power needs of such devices have so far been met by Li-ion batteries and other primary battery technologies, resulting in a consequent rise in their consumption. These batteries often contain heavy metals and strong electrolytes which make them one of the most hazardous components of electronic waste.1 In addition, the majority of the primary Li batteries used globally are not recycled nor properly disposed of, thus ending up in landfills without regulations.2 In applications that do not require long discharge times and have modest capacity requirements such as medical devices, these batteries are not even fully discharged before being disposed of. This requires further resources for re-extracting the materials if not recovered, which is not sustainable and raises concerns about the abundance of these resources. The end-of-life fate of these batteries and their life cycle assessment therefore only justifies the use in rechargeable applications beyond hundreds of cycles.3,4 These issues trigger a worrying concern about associated future environmental hazards from the battery waste generation and urgently call for novel alternatives, tightened environmental policies and switching the linear consumption habit of "take-make-dispose" for these primary batteries into a circular economy model. This approach utilizes novel concepts such as green electronics and cradle-to-cradle design to eliminate waste from the conc...

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In-situ characterization of symmetric dual-pass architecture of microfluidic co-laminar flow cells

Cited by 34 publications

References 24 publications

Co-laminar flow cells for electrochemical energy conversion

Co-laminar flow cells for electrochemical energy conversion

Design of a radial vanadium redox microfluidic fuel cell: A new way to break the size limitation

Evaluation of Redox Chemistries for Single-Use Biodegradable Capillary Flow Batteries

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