Solid electrolytes cell construction

The alkali metals—lithium, sodium, and potassium—are logical choices for anodes in a sulfur-based electrochemical cell. All three have been incorporated into cells, and lithium and sodium remain under serious consideration. The lithium-sulfur combination is the topic of another chapter in this volume and will not be discussed further. Two types of sodium-sulfur cells have been constructed. One type uses thin-walled glass capillaries as a cell divider, and the other uses various sorts of ionically conducting sodium aluminate for this purpose. Of the two, the latter seems to hold the most promise and certainly has generated the most interest and enthusiasm (1). Because of the unique properties of the solid electrolyte cell separator this battery is also probably the most interesting from a purely scientific point of view. 

Matsumoto M, Miyazaki H, Matsuhiro K, Kumashiro Y, Takaoka Y (1996) A dye sensitized Ti02 photoelectrochemical cell constructed with polymer solid electrolyte. Solid State Ionics 89 263-267... 

Solid electrolytes are frequently used in studies of solid compounds and solid solutions. The establishment of cell equilibrium ideally requires that the electrolyte is a pure ionic conductor of only one particular type of cation or anion. If such an ideal electrolyte is available, the activity of that species can be determined and the Gibbs energy of formation of a compound may, if an appropriate cell is constructed, be derived. A simple example is a cell for the determination of the Gibbs energy of formation of NiO ... 

Two earlier reviews were published on high temperature cells and batteries based on molten salt and solid electrolytes. The first one (69) describes the Li/Cl2 cells, particularly the LiA.l/LiCl-KCl/Cl2 cell with gaseous CI2. Li cells with chalcogenides as cathode materials are mentioned, as well as some details of construction. This review, and the 26 references attached to it, reflects the state of the Li molten salt batteries to the end of 1970 (69). The second review (70), prepared two years later is more comprehensive. It discusses in detail some theoretical problems, the thermodynamics and rate processes in electrochemical cells, and presents tables and... 

Solid oxide fuel cells (SOFC) use a hard, non-porous ceramic compound as the electrolyte. Since the electrolyte is a solid, the cells do not have to be constructed in the plate-like configuration typical of other fuel cell types. SOFCs are expected to be around 50-60 percent efficient at converting fuel to electricity, however, calculations show that over 70 percent may be achievable. In applications designed to capture and utilize the system s waste heat (co-generation), overall fiiel use efficiencies could top 80-85 percent. 

Although the electrolyte is strongly acidic, cell construction is less demanding as the solid electrolyte does not cause corrosion problems. 

Hibino, T., Wang, S., Kakimoto, S., and Sano, M. Single Chamber Solid Oxide Fuel Cell Constructed from an Yttria-Stabilized Zirconia Electrolyte, Electrochem. Solid-State Letters, 2, 317 (1999). 

It has been found that Zr02(s) stabilised with CaO or YO, 5 is an ionic conductor of oxygen ions in certain ranges of oxygen pressure and temperature. Using this material as the solid electrolyte, an oxygen concentration cell can be constructed ... 

A typical cell construction is shown in Figure 10.3. Natural manganese dioxide ore is blended with acetylene black and Leclanche electrolyte, and molded into a round bobbin shape with a carbon rod current collector in the center. This molded cathode is then inserted into a zinc can. A paste-coated paper separates the zinc can and the Mn02 cathode. This provides a barrier to prevent solid particles... 

The construction of operational, hermetically sealed sodium-sulfur cells requires container materials, which are mechanically suitable and compatible with sodium and sulfur-sodium polysulfide, current leads to the sulfur-graphite electrode, and several kinds of seals. These requirements of course are in addition to those for the solid electrolytes and sulfur electrodes described earlier. The problem of satisfying these requirements has been summarized by Gratch and co-workers (3). Particular applications—utility load-leveling, traction power, and military— impose further design constraints dictated by performance, capacity, size and weight, life, cost, and safety requirements. 

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