Segmented fuel cell

Galvanostatic discharge of a fuel cell (MRED method) provided information related to liquid water in a fuel cell in a minimally invasive manner.157 Stumper et al.158 showed that through a combination of this MRED method with a current mapping (segmented fuel cell similar to the one discussed in Stumper et al.135), it was possible to obtain the local membrane water content distribution across the cell area. The test cell was operated with a current collection plate segmented on the cathode along the reactant flow direction. In addition to the pure ohmic resistance, this experimental setup allowed the determination of the free gas volume of the unit cell (between the inlet and outlet valves). Furthermore, the total amount of liquid water presented in the anode or cathode compartment was obtained. 

Figure 10. Schematic of the segmented fuel cell design using printed circuit board (PCB) technology (with kind permission from Springer Science+Business Media 1 9 Fig. 1).

An equivalent circuit of the segmented fuel cell is shown in Figure 7-17. is the lateral surface resistance between neighbouring cells which may result from insufficient removing of the electrode layers in the segmentation procedure. and are the open circuit voltage, the ionic mem-... 

Figure 7-17. Equivalent circuit of the segmented fuel cell...

Multichannel systems also allow more advanced tests to be performed, for example testing a segmented fuel cell where one electrode has been partitioned to investigate different electrode materials or to do impedance mapping of the fuel cell electrode. Different materials can also be simultaneously screened in a common corrosive environment using a multichannel potentiostat system with several working electrodes and one counter electrode and a reference electrode. 

FIGURE 8-14. Segmented fuel cell design used for current density mapping [15], (Reprinted with kind permission of Spinger Science and Business Medicine.)... 

The introduction of a new product or technology is always accompanied by different circumstances that promote or prevent its success on the market. If there is no public acceptance, for example, fuel-cell technology will be hard put to gain important market segments. But there are also other barriers to be overcome. 

Figure 9. Schematic diagram of the segmented cell approach inside the fuel cell (reprinted from146 Copyright (2006), with permission from Elsevier).

Current distribution in PEM fuel cell can be determined not only by setting up segmented cells, electrically isolated from each... 

Current distribution studies have also been used to develop optimal loading gradients for compounds within a PEM fuel cell. Santis et al.174 utilized a segmented plate design with Hall-effect sensors... 

Current density distribution along the active area in a fuel cell is a very critical parameter that needs to be understood completely in order to improve the design of each component of a cell. So far, one limitation prevailing in much of the published work regarding segmented cells is the difficulty in producing a similar level of current... 

This case is of particular importance because it represents the configuration of the Integrated Planar SOFC (IP-SOFC) developed by Rolls-Royce Fuel Cell Systems, the tubular configuration developed by Siemens Power Corporation, and the segmented configuration. 

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