A circular membrane for nano thin film micro solid oxide fuel cells with enhanced mechanical stability
Baek, Jong Dae
Date of Issue2015
School of Mechanical and Aerospace Engineering
We demonstrate a new architecture for a low temperature solid oxide fuel cell to enlarge the lateral dimension of the fragile nano thin film electrolyte from the micrometer to millimeter scale with greatly enhanced mechanical stability. The new structure was achieved by simple silicon micromachining processes to change the membrane shape from a square to a circle to reduce buckling-induced stress concentration that often caused membrane fracture. A tapered silicon membrane support with the thickest end of 30 μm was introduced as an effective membrane stress absorber. The new architecture effectively suppressed membrane buckling and decreased the maximum principal stress by 30–40%. The largest lateral dimension of the stable membranes was 3 mm in diameter, and the survival rate was significantly improved over square membranes having the same lateral dimension. Fuel cells with 100 nm-thick electrolytes showed stable open circuit voltages of 1.12 V at 400 °C for more than 8 hours without any membrane failure observed, showing the superior mechanical stability of the new cell architecture that is promising in the further practical applications of such devices.
Energy & Environmental Science
© 2015 The Author(s) (Royal Society of Chemistry). This is the author created version of a work that has been peer reviewed and accepted for publication by Energy & Environmental Science, The Author(s) (Royal Society of Chemistry). It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1039/C5EE02328A].