Evaluation of Fuel Gas Supplying Method in Solid Oxide Fuel Cell with Flat-Tubular Structure

摘要

Solid oxide fuel cells (SOFCs) with flat-tubular structure were successfully fabricated by ceramic wet processing. The SOFCs had three or four internal channels for fuel gas flow and were supported by the fuel electrode. The SOFCs were composed of 8 mol Y_(2)O_(3)-ZrO_(2) (YSZ) electrolyte, Ni-YSZ fuel electrode, and La_(0.8)Sr_(0.2)MnO_(3) air electrode. Fuel gas was uniformly supplied to fuel electrodes with fuel gas pipes made of a heat-resistant alloy. The SOFCs had an active area of 50 cm~(2) and were operated to achieve a maximum power density of 0.23 W/cm~(2) at 1000 °C. The effect of the fuel gas pipe on cell performance was recognized; the performance was twice as high as that of an SOFC without the fuel gas pipe. The performance of the SOFC with four channels was slightly higher than that with three channels. It also appeared that the performance of the SOFC with three channels decreased steeply with increasing fuel utilization.