Fuel cell laminar flow based

Micro fuel cell designs without polymeric membranes can overcome some PEM-related issues such as fuel crossover, anode dry-out or cathode flooding. In these membraneless laminar flow-based fuel cells (LF-EC) two or more liquid streams merge into a single microfluidic channel. The stream flows over the anode and the cathode electrodes placed on opposing side walls within the channel. The reaction of fuel and oxidant takes place at the electrodes while the two liquid streams and their liquid-liquid interface provide the necessary ionic transport [122,123]. 

Laminar flow-based fuel cells Membraneless fuel cells Microfluidic biofuel cells... 

These types of three-dimensional electrodes on microchips could also be used for a wider variety of biomethods, including electroporation, drug delivery, and electrostimulated cell culturing. Three-dimensional electrodes will also have applicability in laminar flow-based fuel cells and biofuel cells due to the increase in roughness factor. Three-dimensional electrode... 

Mousavi Shaegh, S.A., Nguyen, N.-T., and Chan, S.H. (2011) A review on membraneless laminar flow-based fuel cells. Int.J. Hydrogen Energy, 36 (9), 5675-5694. 

Figure 18.10 Schanatic of the membraneless laminar flow-based fuel cell. Regions of fuel-oxidant depletion as well as regions of diffusional fuel-oxidant crossover are indicated (not drawn to scale). (From Choban, 2004, with permission from Elsevier.)...

Microfluidic fuel cells, also known as membraneless fuel cells or laminar flow-based fuel cells, represent an emerging fuel cell technology capable of integration and operation within the framework of a microfluidic chip. In microfluidic fuel cells, all functions and components related to reactant delivery, reaction sites, and electrode structures are confined to a single microfluidic channel. Microfluidic fuel cells predominantly operate using co-laminar flow of fuel and oxidant electrolytes without a physical barrier, such as a membrane, to separate the two half-cells. 

Recently, membraneless laminar flow-based fuel cells are being explored and beginning to emerge. They are primarily aimed at avoiding ionomer membranes, which have disadvantages, most notably their change in size with humidification and their incompatibility with microtechnology. 

In this chapter, the fundamentals of the membraneless laminar flow-based fuel cells (LLFCs) operation are first explained. Then, design and exploited fabrication technologies of membraneless LFFCs and the effect of flow architectures of electrodes and their arrangements on cell performance are discussed. Subsequently, reader can find more details about the proposed fuels, oxidants, and electrolytes for membraneless LLFCs. Finally, some discussions on material constraints and selections are provided. 

Brushett, F.R., Jayashree, R.S., Zhou, W.P., and Kenis, P.J.A. (2009) Investigation of fuel and media flexible laminar flow-based fuel cells. Electrochimica Acta, 54 (27), 7099-7105. 

Jayashree RS, Gancs L, Choban ER, Primak A, Natarajan D, Markoski LJ, Kenis PJA (2005) Air-breathing laminar flow-based microfluidic fuel cell. J Am Chem Soc 127 16758-16759... 

R.S. Jayashree, L. Gancs, E.R. Choban, A. Primak, D. Natarajan, L.J. Markoski, P.J.A. Kenis, Air-breathing laminar flow-based microfluidic fuel cell. Journal of the American Chemical Society, 2005, 127, 16758-16759. 

Choban ER, Spendelow JS, Gancs L, Wieckowski A, Kenis PJA (2005) Membraneless laminar flow-based micro fuel cells operating in alkaline, acidic, and acidic/alkaline media. Electrochim Acta 50(27) 5390-5398... 

Besides the rapidly increasing citation trend, a detailed review of the actual number of publications reveals more useful information. The publication chart presented in Fig. 6.2 accounts for all peer-reviewed scientific publications that report new findings on co-laminar flow-based microfiuidic electrochemical cells, which form the core of this field. To avoid biasing effects, review articles and contributions on peripheral fuel cell technologies with flowing electrolytes [1-4] or mixed reactants [5-12] were not included. Overall, as indicated by the trendline, the total number of scientific articles on microfiuidic fuel cells and batteries has iuCTeased considerably over the past decade and exceeded 20 per year by the end of 2013. 

Fig. 6.2 Number of journal publications on co-laminar flow-based microfluidic electrochemical cells (including both fuel cells and batteries). Reproduced and adapted with permission from Goulet and Kjeang [37]...

Choban, E.R. Markoski, L.J. Wieckowski, A. Kenis, P.J.A. Microfluidic fuel cell based on laminar flow. J. Power Sources 2004, 128, 54-60. 

Finally, it is worth mentioning the microfluidic fuel cells concept [103] introduced by Whitesides in 2002 [104], based in a membraneless fuel cell design which exploit the laminar flowl that occurs in liquids flowing at low Reynolds number to eliminate convective mixing of fuels. Using this concept on-chip, membraneless, air-breathing monolithic pDAFC has been constmcted by Osaka and coworkers [105, 106] which operate with methanol, ethanol and 2-propanol solution containing sulphuric acid or phosphate buffer. The cell consists of two cathodes at the top of the channel, and the hquid fuel is supphed by capillary force to the anode formed on the bottom of the channel, as indicated in Fig. 1.12a, b. 

Choban ER, Markoski LJ, Wieckowski A, Kenis PJA (2004) Microfiuidic fuel cell based on laminar flow. J Power Sources 128 54... 

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