Solid oxide fuel cells basic components

A detailed description of the energy conversion processes through electrochemical reactions in a fuel cell is given here by considering a hydrogen-oxygen polymer electrolyte membrane fuel cell (PEMFC) and a solid oxide fuel cell (SOFC) with basic cell components as shown in Figures 4.6 and 4.7, respectively. Similar descriptions for other types of fuel cells will be presented in Chapter 9. 

Figure 35.6 Scheme of the basic components of the solid oxide fuel cell based on oxygen ion conductor electrolytes. 

Desaunay T, Ringuede A, CassirM, Labat P, Adamo C Modeling basic components of solid oxide fuel cells using density functional theory bulk and surface properties of Ce02, Sutf Sci 606(3-4) 305-311, 2012. 

The basic components of a general fuel cell are two porous electrodes, i.e. anode and cathode, which are separated by a solid or liquid electrolyte. The electrolyte is impervious to gases. Fuel is supplied to the anode side and air is supplied to the cathode side. The oxidation reaction is made possible by conduction of ions through the electrolyte. Although the basic principle behind the operation of a fuel cell is quite simple, many challenges have to be overcome before its successful implementation. 

There are two basic designs of SOFC units. In the planar design, components are assembled in flat stacks where the air and hydrogen traditionally flow though the unit via channels built into the anode and cathode. In the tubular design, air is supplied to the inside of an extended solid oxide tube (which is sealed at one end), whilst fuel flows round the outside of the tube. The tube itself forms the cathode, and the cell components are constructed in layers around the tube. 

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