LSM Protective Coatings on Stainless Steel as Interconnects for Solid Oxide Fuel Cells
Published online by Cambridge University Press: 18 March 2014
One of the major barriers to the adoption of solid oxide fuel cells (SOFCs) is the short lifetime of the fuel cell stacks. A stack consists of a number of cells in series separated by an interconnect. Due to the high temperatures necessary for SOFCs, typical commercial interconnects are ceramic. Great attention has been paid to decreasing the operating temperature of SOFCs in order to extend the life and decrease the cost of the stack. As operating temperatures decrease below 1000°C, alternative interconnect materials become viable. Stainless steel interconnects are more cost effective than ceramic interconnects but the high temperatures and the oxidizing environment of the cathode leads to the formation of a chromium oxide scale that increases the stack resistance. Chromium from the stainless steel can also enter the vapor phase and redeposit on the cathode thereby blocking the electrochemically active sites. One method to neutralize these effects is to coat the metallic interconnect in a ceramic such as La.8Sr.2MnO3 (LSM). The coating acts as a diffusion barrier both against chromium diffusing into the cathode and oxygen diffusing into the interconnect. In this study LSM has been deposited using plasma spray and tested in a dual atmosphere setup using impedance spectroscopy to analyze the performance of the coatings at various temperatures. The area specific resistance and chemical composition of the scale was examined in order to determine the affect of the LSM coating.
- MRS Online Proceedings Library (OPL) , Volume 1644: Symposium DD – Materials and Technologies for Grid-Scale Energy Storage , 2014 , mrsf13-1644-dd05-03
- Copyright © Materials Research Society 2014