Highly thermal integrated heat pipe-solid oxide fuel cell

Temperature gradient is a significant problem for the practical application of solid oxide fuel cells (SOFCs), which may lead to low power density and the degradation of SOFCs. In order to equalize the temperature distribution and improve the electrochemical performance, the concept of a heat pipe with liquid sodium metal is introduced into the design of SOFCs. A highly thermal integrated heat pipe-solid oxide fuel cell (HP-SOFC) was fabricated and investigated. The HP-SOFC consists of a heat functional layer, a current-collecting layer, an anode layer, an electrolyte layer, and a cathode layer. For an extreme flame operation, the temperature gradient along the axis of the tubular SOFC decreases from 31 to 13 K/cm due to the high heat-transfer rate of the heat functional layer. For a single fuel cell, the power output is significantly improved by 65%, increasing from 73 to 120 mW/cm² at 0.6 V with a methane-rich flame at an equivalence ratio of 1.7. In addition, prospects for other possible applications of the HP-SOFC are discussed.