The principal objectives of this proposal are the fabrication and evaluation of intermediate temperature (700 C) planar solid Oxide Fuel Cell (SOFC) stacks developing at least 1 kW and up to 1.5 kW electrical power using natural gas. The stacks will be based on self-supported ceramic electrochemical cells incorporating Ce0.9 Gd0.1 O1.95 (CGO) based electrolytes (130 um thick) which will be scaled up from approximately 25 cm2 to 100 cm2 area during the project. The low temperature of operation of the cell will allow ferritic stainless steel with appropriate functional layers to be used as the bi-polar plate material.
The operation of solid oxide fuel cells at reduced temperature overcomes one of the major cost limiting problems of SOFCs i.e. elimination of the need for ceramic or expensive alloy interconnect and separator plates.
This project seeks to evaluate and optimise an intermediate temperature SOFC set up, based on CGO initially at small scale but ultimately in stacks developing 1.5 kW. Current ceramic electrolyte powders whilst demonstrating potentially useful electrical properties are not suited for the fabrication of thin plates. Optimised ceramic powders will be manufactured and two fabrication routes (an established tape casting technique, and a more novel viscous plastic processing) used to produce PEN components. The performance of these small PENs will be evaluated in purpose built test rigs, and further optimisation of both materials and processing carried out as required. The statistical data obtained from the performance trials will form the basis of an evaluation of the two fabrication routes.
Low temperature operation will demand new reforming catalysts. Two catalysts for reforming of the fuel will be developed and incorporated into the test set up.
Once optimised, the PEN structures will be scaled up and two designs of stacks assembled. Performance of the stacks using a variety of self sustaining operation conditions will be monitored and evaluated.
Expected Achievements and Exploitation
Success in this project will impact on a number of areas. In addition to the main exploitation route through manufacture and sale of intermediate temperature SOFC systems based on CGO electrolyte and ferritic steel bipolar plates, the development of specific aspects of the project such as electrically conducting oxidation resistant coatings for steels, are likely to have wider implications outside the SOFC field.
Development of optimised electrode interfaces will impact on high temperature SOFC and other electrochemical systems, as will the development of low temperature reforming catalysts for natural gas.
Funding SchemeCSC - Cost-sharing contracts
S9 1TR Sheffield
1755 ZG Petten
7300 AC Apeldoorn