Fuel cell structure

Crown A, Kin H, Lu GQ, de Moraes IR, Rice C, Wieckowski A. 2000. Research toward designing high activity catalysts for fuel cells Structure and Reactivity. J New Mater Electrochem Syst 3 275. 

The fuel cell Rankine cycle arrangement has been selected so that all fuel preheating and reforming are carried out external to the cell and air preheating is accomplished by mixing with recycled depleted air. The air feed flow is adjusted so that no heat transfer is required in the cell or from the recycled air. Consequently, the internal fuel cell structure is greatly simplified, and the requirement for a heat exchanger in the recycle air stream is eliminated. 

Wilkinson, D. P, and St-Pierre, J. In-plane gradients in fuel cell structure and conditions for higher performance. Journal of Power Sources 2003 113 101-108. 

Figure 1.8. Alkaline fuel cell structure [14]. (Reproduced from International Journal of Hydrogen Energy, 27(5), McLean GF, Niet T, Prince-Richard S, Djilali N, An assessment of alkaline fuel cell technology, 507-26, 2000, with permission from the International Association of Hydrogen Energy.)...

Figure 3.39. Water concentration in an interdigitated PEM fuel cell structure, for three planes at x-values corresponding to the flow channel exit (a top left), the middle (b top right) and the entrance (c bottom left). In each pair of pictures, the y-z plots depict the hydrogen side at the top (GDL is lower bar) and the oxygen side at the bottom (GDL is upper bar). The cell current is at its maximum (about 0.8 A cm" ). (From M. Hu et al, (2004). Three dimensional, two phase flow mathematical model for PEM fuel ceU Part II. Analysis and discussion of the internal transport mechanism. Energy Conversion Management. 45,1883-1916. Used with permission from Elsevier.)...

The theoretical tools discussed in this contribution address various optimization tasks in PEMFC research (i) highest system efficiencies and fuel cell power densities and, thus, minimum overvoltage losses in CCLs (ii) optimum catalyst utilization and, thus, minimal Pt loading (and minimal cost), and (iii) waterhandling capabilities of CCLs and their impact on the water balance of the complete fuel cell. Structural parameters, as well as operating and boundary conditions that control the complex interplay of processes enter at three major levels of the theory. 

As documented in and expressed by these various contributions, the topic Polymers for Fuel Cells is a vast one and concerns numerous synthetic and physico-chemical aspects, derived from the particular application as a solid polymer electrolyte. In this collection of contributions, we have emphasized work which has already led to tests of these polymers in the real fuel cell environment. There exist other synthetic routes for proton-conducting membrane preparation, which are not discussed in this edition. Furthermore, certain polymers are utilized as fuel-cell structure materials, e.g., as gaskets or additives (binder, surface coating) to bipolar plate materials. These aspects are not covered here. 

Nasef M, Zubir NA, Ismail AF, Khayet M (2006) Sulfonated radiation grafted pofystyrene pore-filled poly(vinylidene fluoride) membranes for direct methanol fuel cells structure— property correlations. Desalination 200 642-644... 

Nasef, M.M., Saidi, H. and Dahlan, K.Z.M. 2010b. Radiation grafted polyfvinylidene fluoride)-gra -polystyrene sulfonic acid membranes for fuel cells Structure-property relationships. Chin.. 1. Pohm. Sci. 28 761-770. 

K., and Watanabe, S. (2006) Study of fuel cell structure and heating method development of JARl s standard single cell. J. Power Sources, 155, 182-189. 

Huang A, Xia C, Xiao C, Zhuang L (2006) Composite anion exchange membrane for alkaline direct methanol fuel cell structural and electrochemical characterization. J Appl Polym Sci 100 2248-2251. doi 10.I002/app.23579... 

Niedrach LW, Alford HR (1965) Novel fuel cell structure. US Patent 3905832, Chem Abstr 62 11416c... 

Kelland, J.W. and S.G. Braun. 1992. Unitized fuel cell structure. U.S. Patent 5187025. 

Figure 4.21 PEM fuel cell structure along the lines of u,, Sources Ltd.

When residual water produced during fuel cell operation remains in the electrodes after the stack is shut down, problems can arise, particularly when the environmental temperature is <0 °C. When the stack is exposed to subzero conditions, the residual water will freeze, so the volume of the electrodes (in particular, the catalysts layers) will expand due to ice formation, which will lead to structural damage and decreased electrochemical active surface area. This has been reported as an additional degradation mechanism in PEM fuel cells [21]. However, if the PEM fuel cell is operated at high temperatures, less liquid water will remain in the electrode and thus decrease the impact of fuel cell structure failure caused by frozen water. 

Fig. 14.4 Schematic diagram of hydrogen membrane fuel cell structure...

Damiano, P. J., Fuel cell structure, U.S. Patent No. 4,129,685, 1978. Wilkinson, D. P. and O. Vanderleeden, Serpentine Flow Field Design, in W. Vielstich, A. Lamm, and H. Gasteiger (editors). Handbook of Fuel Cell Technology—Fundamentals, Technology and Applications, Vol. 3, Part 1 (John Wiley. Sons, New York, 2003) pp. 315-324. 

PaxiTech website http //www.paxitech.com (accessed February 2005). Wilkinson, D. P. and J. St-Pierre, In-Plane Gradients in Fuel Cell Structure and Conditions for Higher Performance, Journal of Power Sources, Vol. 113, No. 1, 2003, pp. 101-108. 

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