Development of Highly Robust, Volume-Manufacturable Metal-Supported SOFCs for Operation Below 600°

Abstract

Ceres Power has been developing fuel cell stacks and mCHP systems based on its unique metal-supported SOFC design incorporating a Gadolinia-doped ceria (CGO) electrolyte operating in the 450-600°C temperature range. The present generation of cells being manufactured are designed to meet the commercial requirements for a wall mounted, natural gas fuelled mCHP product, producing an average of 140mWcm-2 at 0.75V/cell at 570°C and 60% fuel utilization, operating on steam-reformed natural gas. Open-circuit voltages are around 1.10V operating on hydrogen/nitrogen; close to theoretical values indicating the effective suppression of internal short-circuits. The unique metal supported design facilitates simple and robust hermetic sealing of the cell to the interconnect by welding, and layer-to layer sealing and isolation is achieved using a commercial gasket material, thus largely eliminating degradation due to thermal stress induced seal leakage found in conventional planar SOFC designs.