The innovation was chosen from in sum over 600 applications for the 1st prize within one of the 5 categories, „Steel in Research & Development/Processes“. Another two JARA-ENERGY institutions were among the 12 finalists of this category. In order to be eligible for an award, the innovations have to open up new areas of use for steel, allow efficient production, be environmentally advanced, improve the functionality of products or substitute other materials.
The new material Crofer® 22 H (1.4755 - X1CrWNbTiLa22-2) invented by Willem J. Quadakkers and Leszek Niewolak of Forschungszentrum Jülich in cooperation with Heike Hattendorf of ThyssenKrupp VDM can be used for innovative and efficient high-temperature energy applications as high-temperature fuel cells (Solid Oxide Fuel Cell (SOFC)).
For efficient use and to build up high voltages, several fuel cells are connected in series. The individual fuel cells are connected to each other by an electrically conductive interconnector plate, which at the same time contains supply channels for fuel and oxygen and provides the whole system with the required mechanical stability.
The material Crofer® 22 H possesses all of the properties required for the applications of SOFC interconnector plates, such as a coefficient of expansion adapted for the electrolytes, high corrosion resistance in air and wet fuel gas, high electrical conductivity of the oxide layers and good plasticity. Crofer® 22 H also contains additives such as niobium, tungsten and silicon which, by forming a very finely dispersed Laves phase, ensures particularly high temperature strength and creep resistance. The inner oxidation of the silicon that occurs with other materials and is harmful for SOFC applications is suppressed by an almost complete dissolution of the silicon in the Laves phase. The innovative alloy also provides improved oxidation resistance for thin-walled interconnectors due to the high creep resistance.
ThyssenKrupp VDM has already successfully melted Crofer® 22 H with the comparatively low-cost conventional steelworks technology and processed it into strips, wire and rods. The new material is therefore ideal for the low-cost manufacture of interconnector plates and can therefore promote the general spread of fuel cell technology.
Prof. Dr. Willem J. Quadakkers (centre), Institute for Energy and Climate Research at Forschungszentrum Jülich, is awarded with the first place of 2012 Steel Innovation Prize by patron Prof. Dr.-Ing. Wolfgang Reitzle (left) and Dr. Jost A. Massenberg (right), chairman of Stahl-Informations-Zentrum.
The individual fuel cells are connected to each other by an electrically conductive steel interconnector plate, here a 5 kW Solid Oxide Fuel Cell Stack.Source: Forschungszentrum Jülich