Solid electrolyte water electrolyser

The General Electric solid electrolyte water electrolyser is presently only available as small units but the development of very large units is well under way. 

Figure 5.5 View from above of two of a bipolar stack of solid electrolyte water electrolyser cells.

Table 5.1 Estimated voltage distribution in a solid electrolyte water electrolyser at 80°C and an operating current density of 1.08 A cm. ...

Antonucci V, Di Blasi A, Baglio V et al (2008) Fligh temperature operation of a composite membrane-based solid polymer electrolyte water electrolyser. Electrochim Acta 53 7350-7356... 

Three types of water electrolyser based on a tank cell, a filter press design and the use of elevated pressure are presently manufactured in various sizes to meet the various markets described above. In addition, a solid electrolyte cell is expected to become available by the mid-1980s. All these cells are described below. 

Proposed and actually developed utilisations of solid electrolytes are very varied and range from simple refractory heating elements as demonstrated by Nernst at the end of the last century (l) to advanced analogue memory components (2) and high temperature water electrolyser. 

The solid polymer electrolyte cell tends to be slightly larger than corresponding high-pressure cells, and requires a compressor to remove the hydrogen gas. However, it has a number of important advantages compared to other water electrolysers ... 

Two cases were examined for the production of water electrolysis. Data were taken from Reference (1) and adjusted to mid-1979 levels in accordance with Table 1. The costs of "current technology" electrolysis were averaged in Reference (1) from information provided by Lurgi, Electrolyser Corp., General Electric, and Teledyne Isotopes. An advanced electrolyzer design, based upon the General Electric Solid Polymer Electrolyte (SPE) design, was also addressed as the second case. 

Abstract This chapter is dedicated to some significant applications of membranes in the field of energy, focusing on fuel cells and electrolytic cells. Both electrochemical devices are part of an international effort at both fundamental and demonstration levels and, in some specific cases, market entry has already begun. Membranes can be considered as separators between cathodes and anodes. As fuel cells are extremely varied, with working temperatures between 80°C and 900°C, and electrolytes from liquid to solid passing by molten salts, they are of particular interest for the research and development of new membranes. The situation is quite similar to the case of electrolysers dedicated to water electrolysis. The principal features of these devices will be outlined, with emphasis on the properties of the state-of-the-art membranes and on the present innovations in this area. 

Several processes and devices are currently developed for water electrolysis such as aUcaline systems, solid oxide electrolyte, and PEM-based electrolysers. PEM water electrolysis is crmsid-ered the most promising method to produce hydrogen with a high degree of purity from renewable energy resources such as wind. 

Fig. 5 7 Solid-polymer electrolyte cells for water electrolysis, (a) Reactions, (b) The cell arrangement (c) A demonstration electrolyser module which incorporates 34 cells and will generate up to 14 m h of hydrogen. (Courtesy CJB Developments Ltd.)...

The solid HPAs showed promising improvement in conductivity and fuel cell performance but dissolved in water formed by the electrochemical process of current generation [9]. This leaching of the acids led to a decay in the performance of the fuel cells. To overcome the problem of electrolyse dissolution and the consequent short lifetime of the fuel cell, an approach was investigated in which the HPA was blocked inside a host material in such a way that it would maintain high proton conductivity of the original electrolyte. The immobilization of the HPA on a support could be attained by any of the three processes physisorption, chemical attachment, and entrapment. Since weak forces are involved in physisorption because the HPA is just physically adsorbed on the support material, it is not an effective method to avoid the solubilization and leaching of the HPA from the support. The processes of immobilization by chemical attachment or entrapment are more effective as they form covalent or ionic bonds with the host material and very stable materials can be prepared. 

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