Typical cell designs

Despite this diversity there are clearly some general rules in cell design these would include the following  

The section will discuss some typical examples of these principles of cell design and each subsequent chapter will deal with cell design in the more specific context of the particular application. 

The great advantage of the tank cell is the simpUcity of construction and the wide range of materials which can be used for the manufacture of the simple components required. It is, however, Umited in space time yield and unsuited to large-scale operation or to a process where control of the mass transport conditions is necessary. 

Most industrial flow cells are based on the parallel-plate electrode configuration and again the electrodes may be horizontal or vertical. 

The most common cell with horizontal electrodes is the mercury cell from the chlor-alkali industry (see Chapter 3). The mercury cathode flows down the slightly sloping base plate of the cell and many rectangular dimensionally stable anodes (DSA) (of gauze or expanded-metal-type structure to allow the chlorine gas to rise with only minimum restriction) are mounted from the top of the cell so that they cover the surface area of the mercury and give an inter-electrode gap of a few centimetres (see Fig. 2.13). The cell may be as big as 70 m. The brine is, however. 

---

Different reactors have been employed for various bench-scale and industrial-scale electrochemical processes. A partial listing of typical cell designs follows. More information on electrochemical reactors can be found in [28, 30, 33]. 

Following Goodridge [29], Walsh has classified reactors according to the electrode structure motion [4, 8, 17]. In the present case, the cathode may be static or moving with 2- or 3-dimensional character as a subdivision (table 4) and typical cell designs suggested by this classification have been considered elsewhere [4, 5, 8, 17, 20]. 

Instrumentation. In most studies reported so far. X-ray radiation of a synchrotron collimated and monochromatized with suitable optics is used. An electrochemical cell with a moving working electrode is employed in order to minimize X-ray absorption by the electrolyte solution. A typical cell design is depicted in Fig. 6.10. 

The main components of a PAFC are bipolar plates, gas diffusion layers, catalyst layers, and matrix layer [3]. Typical cell designs include a sandwich of these layers as arranged in Fig. 12.2 between coolers. Multiple cells per cooler designs are generally employed to improve power density and this unit is called a sub stack. A cell stack assembly consists of multiple sub stacks held between two pressure plates tmder compression to minimize reactant leakage and contact resistance losses. 

A typical cell design for a cyclic voltammetric experiment is shown in Figure 2-4a. The simplest approach is merely to have the three electrodes immersed in the solution in close proximity. A Luggin capillary (Figure 2-4b) further isolates the reference solution from the cell solution. At the outset of the experiment the cell... 

Figure 12.21 (b) and (c) show some typical cell designs for amperometric detectors. 

In a typical cell design (the Gould/Westinghouse 200 Ah cell), the negative electrode is a lithium aluminium alloy, the positive electrode is a solid lithium chloride-potassium chloride and the separator is boron nitride. Magnesium oxide has been used as a separator in other batteries. 

---