Thin Film Solid Oxide Fuel Cells Research Articles

Development of vacuum plasma sprayed thin-film SOFC for reduced operating temperature

The reduction of the operating temperature of planar solid oxide fuel cells (SOFCs) to an intermediate temperature regime of 650–800°C is an important objective in current development activities worldwide, in order to reduce production costs and improve long-term stability. In addition, existing conventional SOFC production processes must be further developed towards automated production lines, and new manufacturing processes with the potential for mass production must be established to meet the strict cost targets for the successful introduction of SOFCs in the strongly competitive energy market. DLR the German aerospace research centre has developed a novel planar thin-film SOFC concept which is based on advanced plasma spray processes. These manufacturing techniques allow the subsequent deposition of the entire membrane-electrode assembly (MEA) onto a porous metallic substrate within a very short process time, and has the potential to be developed into an automated continuous production process. By applying the plasma spray technology single cells were fabricated and characterised as having high performance in the temperature range 750–900°C and good long-term behaviour. Further development work will concentrate on the assembly of stacks with several large-scale cells with dimensions of 10 × 10 and 20 × 20 cm 2 , in order to obtain stack performance and durability results.

Testing of Solid-Oxide Fuel Cells for Micro to Macro Power Generation

Thin film, solid-oxide fuel cells (TFSOFCs) are developed using photolithographic patterning and physical vapor deposition. In this study, both electrode layers of nickel (Ni) and silver (Ag) as well as the solid- oxide electrolyte layer of yttria-stabilized zirconia (YSZ) are synthesized on the micrometer scale for thickness. The anode layer enables combination of the reactive gases, is conductive to pass the electric current, and provides mechanical support to the electrolyte and cathode layers. The morphology desired for both the anode and cathode layers facilitates generation of maximum current density from the fuel cell. For these purposes, the parameters of the deposition process and post- deposition patterning are optimized for continuous porosity across both electrode layers. The electrodes are characterized using scanning electron microscopy and the power output generated through current-voltage measurement. We find that a TFSOFC based on Ni-YSZ-Ag can be operate d with dilute fuel mixtures at temperatures below 300 C.

Thin-film solid oxide fuel cell with high performance at low-temperature

A planar thin-film solid oxide fuel cell (SOFC) was developed at the Lawrence Berkeley National Laboratory – Materials Science Division. The thin-film SOFC is fabricated with an inexpensive and scalable technique involving colloidal deposition of YSZ on porous NiO–YSZ substrates, yielding SOFCs capable of high power density at an operating temperature of 800°C. The thickness of the YSZ film deposited onto the porous substrates is approximately 10 μm after sintering. Ni–YSZ/YSZ/LSM cells built with this technique have exhibited theoretical open circuit voltages (OCVs), high diffusion limited current densities and high power density. The cells have been tested for long periods of time (over 700 h) and have been thermally cycled from 600–800°C while demonstrating excellent stability over time.