Solid State lonics 35 (1989) 3-9 North-Holland, Amsterdam PREPARATION AND CHARACTERIZATION OF SPE COMPOSITES FOR ELECTROLYZERS AND FUEL CELLS P. ALDEBERT, F. NOVEL-CATTIN, M. PINERI DRF/SPh/PCM, Centre d'Etudes Nuclbaires de Grenoble, 85X, 38041 Grenoble Cedex, France P. MILLET, C. DOUMAIN DTE/STT/LASP, Centre d'Etudes Nucl~aires de Grenoble, 85X, 38041 Grenoble Cedex, France and R. DURAND C.R.E.M.G.P., BP 75, Domaine Universitaire, 38042 Saint-Martin d'Hbres Cedex, France Received 9 May 1988; accepted for publication 10 October 1988 Solid Polymer Electrolyte (SPE) technology is a promising technique for the development of energetically efficient electrolysers (water, brine electrolysis and organic synthesis) and power generators (H2/O2 fuel cell ). In this paper, we present three different methods for the preparation of electrocatalyst-solid electrolyte composites: First, a procedure based on the localized precipitation of noble metal microparticles within a perfluorinated ionomer membrane was developed. Then, the chemical transformation of perfluorinated ionomers which lead to thermoplastic materials onto which can be pressed appropriate electrode structures was made. Finally, the preparation, characterization and use of solutions and gels of perfluorinated ionomers, leading to the realiza- tion of catalyst-based structures suitable for H2/O2 fuel cell applications, were described. I. Introduction The development of Solid Polymer Electrolyte technology (SPE) started in the early 60's with the US space program Gemini and the realization of low temperature H2/O2 SPE fuel cells. In this technol- ogy, porous catalytic structures are bound on each surface of a thin film (of ca. 200 ~tm thickness) of an ionically conductive polymer impregnated with water. Since the introduction of the Nation i mem- branes (fig. 1a), water and brine electrolysis [ 1-4 ] and more recently organic synthesis [ 5,6 ] were de- veloped. Nation materials, and more generally per- fluorinated ionomers are particularly suitable for such applications, as their internal structure includes hy- drophilic zones where the ionic sulphonate groups Nation is a registered trademark of Dupont de Nemours for its perfluorosulfonic acid membrane materials. are clustered (fig. lb); they also are very stable me- chanically, thermally and chemically [ 8 ]. To date, no viable alternative material has been found for SPE applications. Recently, a procedure for the dissolution of Na- tion membranes has been disclosed [ 9,10 ]. The so- lutions obtained are useful for the preparation of more sophisticated electrode structures of high po- rosity and high electroactive area. Such structures are required for the development of high power density SPE fuel cells for terrestrial and extraterrestrial applications. In this paper, we present three different methods for the preparation of SPE-electrocatalyst compos- ites. Emphasis is placed on the techniques of prep- aration. The results concerning water electrolysis and H2/O2 fuel cells are presented, using Nation 1 17 as SPE and platinum as a catalyst. 0 167-2738/89/$ 03.50 © Elsevier Science Publishers B.V. ( North-Holland Physics Publishing Division )