European Fuel Cell Forum 2011 28 June -1 July 2011, Lucerne Switzerland B0708 BZ-BattExt – DMFC as Battery-Extender in solar-boat application Johannes Schirmer a , Regine Reissner a , Jochen Zabold b , Katica Krajinovic c , Thomas Häring d , Stefan Nettesheim e , Joachim Kopf f , Klaus Steinhart g a German Aerospace Center (DLR) Institute of Technical Thermodynamics Pfaffenwaldring 38-40 DE-70569 Stuttgart / Germany Tel.: + 49-711-6862-674 Fax: +49-711-6862-322 Johannes.Schirmer@dlr.de Abstract For special applications Direct Methanol Fuel Cells (DMFC) are close to commercial application or already commercialized today. However for the step from laboratory to a broader market of fuel cells, a significant cost reduction, as well as an improvement in life time and power density of the systems is needed. These items were the focus of the project BZ-BattExt, to be reached by new knowledge in alternative materials, operation strategies as also the realization of enhanced sub systems. In the project a 100W DMFC compact system as battery extender was successfully developed and operated. The reduction of the number of components and the simplification of the system leads to a reduction of price, weight and volume. The project was funded by the German Federal Ministry of Education and Research in the program of Micro fuel cells. In the project the feasibility of a micro-DMFC system was evaluated which enables a minimized system periphery due to an improved system architecture. For this, alternative materials and functional components were developed and investigated. New membranes with reduced water and methanol permeation allow operation at low air stoichiometry and favorable system efficiency. Gas diffusion layers of various compositions were tested and optimized material was selected. New sealing materials with good methanol stability and optimized process ability in commercial production process were developed. MEA preparation was adapted to the new materials. The use of a simple, cost-effective way of stack production was demonstrated for DMFC use. The investigation and construction of enhanced subsystems and operation strategies, which enable and optimize the use of new components and materials, as also the realization of the micro-DMFC system were focus of the project. The technical feasibility of the results was investigated in the application, which means it was tested as battery extender of a solar boat. The DMFC fuel cell system serves as a basis for an efficient, compact and cost effective alternative for battery- or battery-extender systems and can fulfill a broad variety of applications. b Freudenberg FCCT KG, Höhnerweg 2-4, 69465 Weinheim, Germany, jochen.zabold@freudenberg.de c Institute of chemical engineering, Universität Stuttgart, Böblinger Str. 72, 70199 Stuttgart, Germany, Kerres@icvt.uni-stuttgart.de d Between Lizenz GmbH, Feigenweg 15, 70619 Stuttgart, Germany, th@between.eu e Staxon Consultíng GbR, Gardeschützenweg 7, 12203 Berlin, Germany, Stefan.nettesheim@staxon.de f Kopf Solarschiff GmbH, Stützenstr. 6, 72172 Sulz-Bergfelden, Germany, j.kopf@kopf.solarschiff.de g Ulmer Brennstoffzellen Manufaktur GmbH, Helmholtzstr. 8, 89081 Ulm, Germany, klaus.steinhart@ubzm.de B0708 / Page 1-10