Characterization of Limiting Factors in Laminar Flow-Based Membraneless Microfuel Cells

Choban, Eric R.; Waszczuk, P.; Kenis, Paul J. A.

doi:10.1149/1.1921131

Cited by 114 publications

(90 citation statements)

References 11 publications

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“…Although multi-layer designs began with low profile channel height [38], [45], [46], [51], [79], [126]- [133], many of these cells now resemble the high aspect ratio of conventional MEA based cells [133]. The primary advantage behind this sandwich structure fabrication method is the use of standardized off the shelf planar components such as graphite and gaskets which are well known to researchers in the field of fuel cells and flow batteries and do not require any expensive lithography infrastructure.…”

Section: Research Perspectivesmentioning

confidence: 99%

“…Concerning these materials, it is interesting to note the sheer number of reactant combinations that have been attempted with CLFCs. Some of the liquid fuels used include dissolved hydrogen [45], methanol [46], [75], [78], [89], [126], [133], [134], formic acid [38], [54], [75], [79], [81], [123], [127], [129], [131], [135]- [139], hydrogen peroxide [48], [122], V 2+ [37], [55], [56], [58], [87], [92], [94], [96], [105], [106], glucose [80], [83]- [85], [111], [112], [130], glycerol [128], acetate [114], sodium borohydride [75], [91], hydrazine and ethanol [75]. Moreover, it would seem that many CLFC studies focus on other aspects such as catalysis which are not necessarily related to the co-laminar technology [78]- [81], [128], [137], [139].…”

Section: Research Perspectivesmentioning

confidence: 99%

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Co-laminar flow cells for electrochemical energy conversion

Goulet

Kjeang

2014

Journal of Power Sources

104

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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: Research Perspectivesmentioning

confidence: 99%

Section: Research Perspectivesmentioning

confidence: 99%

Co-laminar flow cells for electrochemical energy conversion

Goulet

Kjeang

2014

Journal of Power Sources

104

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“…In this work, we seek to substantially decrease both materials and assembly costs by exploring novel membraneless electrolyzer designs. In addition to eliminating the material costs of membranes and associated components, a membraneless electrolyzer can significantly relax design constraints associated with an MEA-based electrolyzer, opening up the possibility for a substantially simplified overall device that is amenable to low-cost, high volume assembly and manufacturing.Membraneless co-laminar flow-cells based on flow-by band electrodes have been demonstrated for fuel cell [20][21][22][23][24] and flow battery [24][25][26][27] applications. These studies revealed the potential for efficient membraneless device operation without significant crossover of species between the anode and cathode, but face significant challenges to scale-up beyond microfluidic applications.…”

mentioning

confidence: 99%

“…Membraneless co-laminar flow-cells based on flow-by band electrodes have been demonstrated for fuel cell [20][21][22][23][24] and flow battery [24][25][26][27] applications. These studies revealed the potential for efficient membraneless device operation without significant crossover of species between the anode and cathode, but face significant challenges to scale-up beyond microfluidic applications.…”

mentioning

confidence: 99%

Hydrogen Production with a Simple and Scalable Membraneless Electrolyzer

O’Neil

Christian

Brown

et al. 2016

J. Electrochem. Soc.

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Ion-conducting membranes are essential components in many electrochemical devices, but they often add substantial cost, limit performance, and are susceptible to degradation. This work investigates membraneless electrochemical flow cells for hydrogen production from water electrolysis that are based on angled mesh flow-through electrodes. These devices can be fabricated with as few as three parts (anode, cathode, and cell body), reflecting their simplicity and potential for low-cost manufacture. 3D printing was used to fabricate prototype electrolyzers that were demonstrated to be electrolyte agnostic, modular, and capable of operating with minimal product crossover. Prototype electrolyzers operating in acidic and alkaline solutions achieved electrolysis efficiencies of 61.9% and 72.5%, respectively, (based on the higher heating value of H 2 ) when operated at 100 mA cm −2 . Product crossover was investigated using in situ electrochemical sensors, in situ imaging, and by gas chromatography (GC). GC analysis found that 2.8% of the H 2 crossed over from the cathode to the anode stream under electrolysis at 100 mA cm −2 and fluid velocity of 26.5 cm s −1 . Additionally, modularity was demonstrated with a three-cell stack, and high-speed video measurements tracking bubble evolution from electrode surfaces provide valuable insight for the further optimization of electrolyzer design and performance. Solar and wind energy have the potential to power the planet without the environmental impact of fossil fuels, but encounter significant challenges to widespread adoption due to their low capacity factors and inherent intermittency.1 In order to overcome this challenge, affordable grid-scale energy storage technology is needed that can make electricity generation from these technologies more widespread.2 One solution to this issue is to convert excess renewable electricity into stored chemical energy in the form of hydrogen gas (H 2 ), 3 which represents a promising candidate for grid scale energy storage and as a carbon-free replacement of fossil fuels in the transportation and industry sectors. 4 Electrolyzers, which use electricity and water to produce hydrogen and oxygen, are well-established commercially available technologies, 5 but the cost of producing H 2 by water electrolysis is currently too expensive.6-8 Presently, much of the cost of producing H 2 by water electrolysis comes from the price of electricity, 6,8 but as the price of electricity from wind and solar continues to decrease and time-of-use pricing schemes become more prevalent, decreasing the cost of electrolyzer technology will be of great importance to making a renewable hydrogen future a reality.The majority of electrolyzers are based on a design in which the cathode and anode are separated by an ion-conducting membrane or diaphragm. 9 The two most common types of electrolyzers are alkaline and polymer electrolyte membrane (PEM) electrolyzers, which are able to electrolyze alkaline and ultra-pure water, respectively. These electrolyzers are mature t...

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“…This precise control of transport properties enables a wide range of applications, including drug discovery, protein crystallization, biomedical analysis, microfabrication, and energy conversion [87][88][89]. The Kenis group [77,[90][91][92][93][94][95][96][97] and others [86,[98][99][100][101][102][103][104][105][106][107][108][109][110][111] have exploited these microfluidic phenomena to develop a class of membraneless fuel cells that are also referred to as laminar flow-based fuel cells (LFFCs). The laminar nature of flow eliminates the need for a physical barrier, such as an expensive polymeric membrane, while still allowing for ionic transport between the anode and the cathode.…”

Section: Membraneless Fuel Cellsmentioning

confidence: 99%