Tape casting of proton conducting ceramic material

Abstract

International audienceThis work explores experimental procedures for tape-cast proton conducting ceramic fuel cells (PCFC) based on Yttrium-doped Barium Cerate (BCY10). The work is based on several years experience on aqueous tape-casting applied to the shaping of YSZ-based SOFC: however, water-based tape casting of BCY10 appeared to be impracticable for reasons associated with the high basicity of this material that results in rapid hydrolysis when in contact with water. Organic tape casting was therefore developed for BCY10, but only on Electrolyte (BCY10)/Anode (BCY10 + NiO) half cells since up to now no cathode material is available. Planar 20 mm diameter circular half-cells were obtained with the aid of a small load on top of the bi-layer to counterbalance the inevitable warping of the samples. Back-scattered SEM and X-Ray computer-controlled microtomography showed sedimentation of some large grains in the green tapes which are believed to have formed by a mechanism associated with a porosity gradient. The deformation occurring during sintering was modelled taking into account the elastic, thermal, viscoplastic and sintering components of the total deformation. 2D and 3D Finite Element numerical simulations showed that the driving force for deformation is associated with this porosity gradient

High-temperature mechanical behavior of polycrystalline yttrium-doped barium cerate perovskite

“…[1][2][3][4][5][6][7] Substitution of B 4+ sites by trivalent ions in these perovskite oxides causes the formation of oxygen vacancies, which allow for protonic conduction (hydrogen ion transport) rather than the more familiar oxygen ion conduction. Because of the higher mobility of protons, the operating temperature of SOFCs can be safely reduced without degrading performance.…”

IDEAL-Cell, Innovative Dual mEmbrAne fueL-Cell: Fabrication and Electrochemical Testing of First Prototypes

“…A thermal treatment at temperatures in the range of 1000°C is then required to obtain dense layers. The combination of different materials in the same structure involves a number of problems of chemical compatibility (4) and of mechanical stability due to different shrinkage behaviours during the sintering stage and different Thermal Expansion Coefficients (5). Mechanical compatibility problems can be mitigated by the addition of sintering aids, i.e.…”

Processing Ceramic Proton Conductor Membranes for Use in Steam Electrolysis

“…Currently, tape casting is a proven technology for large-scale ceramic components with precisely controlled surface flatness. This versatile approach requires optimally formulated ceramic slurries [ 21 , 22 , 38 ]. Slurries with high solids loading and low viscosity are crucial for obtaining green tape with high density and homogeneous microstructure.…”

“…Many factors can challenge the successful fabrication and upscale of affordable large-sized protonic devices meeting the commercial target. These large-sized devices are generally categorized as tubular or planar, with the planar type preferable for operation due to their advantages [ 21 , 22 , 23 ]. Nonetheless, the fabrication of such multi-layered planar devices, usually via a tape casting process, requires careful control of individual layers’ shrinkages to prevent bending and cracking during sintering [ 22 , 24 , 25 ].…”