Tape Casting of Anode Supports for Solid Oxide Fuel Cells at Forschungszentrum Jülich

Abstract

This contribution describes the development of tape casting for solid oxide fuel cells (SOFCs) anode supports starting with the characterization of the powders and ending with manufacturing of cells for stack testing. After casting the support, full cells were prepared by screen printing and sintering of the functional layers. The results of single‐cell and stack tests of the novel SOFC will be discussed. The new cell showed excellent electrochemical performance in single‐cell tests with more than 1.5 A/cm2 (800°C, 0.7 V). Furthermore, stack tests showed no significant difference from earlier standard cells when operated at 800°C with a current density of 0.5 A/cm2.

Novel ceramic processing method for substitution of toxic plasticizers

“…200 • C and all decomposition is over at around 450 • C. Similar behaviour has previously been reported for comparable systems [23,24]. For the optimum binder compositions, given in Fig.…”

“…This very visual and qualitative initial characterization is similar to the one reported by Schafbauer et al for optimizing the binder content in slurries for tape casting formulations [23] For Hexamoll Dinch, tris(2-ethylhexyl) trimellitate and bis(2-ethylhexyl) terephthalate all of the tested binder mixtures showed signs of sweating or had an opaque appearance. The sweating is believed to be due to an exsolution of excess plasticiser while the opaque appearance is believed to be due to a recrystallization of excess binder both indicating an unwanted poor chemical compatibility of the plasticiser with a PVB and ethanol system.…”

Modeling precursor diffusion and reaction of atomic layer deposition in porous structures

“…The depth z of the porous material was limited to 500 mm, since this is the typical thickness of a tape cast substrate of a SOFC. 45 For t ¼ 0, the precursor molecules were located only outside the porous material, assuming an infinite source and therefore a constant density. In the experiments, at z ¼ 500 mm, the diffusion of precursor molecules was stopped by a heating plate that served as a substrate support.…”

Anode‐Supported Solid Oxide Fuel Cell Achieves 70 000 Hours of Continuous Operation

“…[4][5][6] Here we report the results of al ong-term test using as hort stack with anode-supported cells that recently attained ac ontinuous operation time of 70 000 h( eight years)-the longest operation time ever reached for this technology and almost twice the operation time required for economical, long-term stationary applications.T he stack was operated using humidified hydrogen at 700 8Ca nd ac urrent density of 0.5 Acm À2 .T he anode-supported SOFC variant exhibits superiore lectrochemical per-formance and can also be operatedu sing natural gas at relatively low temperatures. [12] Thus,long-term stability is an important indicatoro ft he technologys developmental status and ak ey prerequisite for its successful commercialization.In seekingt or ealizet his and enhance the performance of anode-supported cells,s cientists at the Forschungszentrum Jülich have been conducting long-running research on materials and manufacturing technology [13,14] and the development of steel for interconnector plates. Our record-breaking result represents am ajor leap forward for this technology and is likely to stimulate renewed researchi nt his area.…”