Flat-chip flame fuel cell operated on a catalytically enhanced porous media combustor

The flame fuel cell is a novel kind of fuel cell that directly combines a fuel-rich flame and solid oxide fuel cells together. Because of their simple setup, low cost, quick start-up and shut-down as well as no extra thermal management, flame fuel cells have great potential in micro-combined heat and power systems and portable applications. However, the conventional solid oxide fuel cell configurations including planar ones and tubular ones, may cause some problems when used in flame fuel cells such as thermal stress, secondary flame front, and difficulty for mass production. To solve these problems, a newly developed flat-chip solid oxide fuel cell is proposed to be used in the flame fuel cell in this study. Combining the merits of both planar and tubular solid oxide fuel cells, the flat-chip fuel cell is advantageous for its simple fabrication technology, good thermal shock resistance and feasibility to scale up. A flat-chip solid oxide fuel cell is fabricated and then integrated with a catalytically enhanced porous media combustor, demonstrating a novel flat-chip flame fuel cell system. The heating time for the flat-chip solid oxide fuel cell by the fuel-rich flame is less than 10 min from room temperature to 800 °C, with a temperature change rate of 5 °C/s in the first stage. The start-up time of the flat-chip flame fuel cell is less than 10 s. When the gas velocity is 6.0 cm/s and the equivalence ratio is 2.0, a peak power density of 179 mW/cm² is obtained for a single cell. Although there exists a remarkable temperature gradient, a small current degradation of 0.01 A/h is observed after a constant-voltage discharging at 0.5 V for 8 hrs. In addition, the flat-chip solid oxide fuel cell can be further scaled up in dimension, resulting in higher fuel utilization of flame fuel cell.