Solid polymer electrolyte electrolyser

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. 

Fig. 12.2 Plate-and-frame electrolyser schemes (a) undivided cell (b) membrane-divided cell (c) solid polymer electrolyte (SPE) reactor (d) membrane-divided cell with GDE (e) SPE-GDE reactor. Liquid compartments are denoted in grey...

Equations 2.24a and 2.24b are the oxidation and reduction steps, occurring at anode and cathode side, respectively, while the protons represent the ion species passing through the solid polymer electrolyte. However, the overall electrochemical reaction is the same of alkaline electrolysers. 

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... 

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 ... 

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.)...

Hydrogen production by electrolysis is a mature technique which has been used for over a hundred years. Most commercial electrolysers are based on the principle of alkaline electrolysis, but solid polymers are also used as an electrolyte. Electrolyser efficiencies range between 65 and 75 %.Units with a hydrogen production of liters to several 10.000 cubic meters per hour are available. 

In order to combine the two structures, electrolyse is trapped within the polymer matrix during polymerization. The result is a solid, thin, flexible electrolyte. Gel electrolytes have clear manufacturing and assembly advantages because of their simplified forms and dual functionalities. However, the performance is a large factor in the ability of such ideas to proliferate. 

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