Preparation and Performances of Tubular Cone-shaped Anode-supported Segmented-in-series Direct Carbon Solid Oxide Fuel Cell
To solve the problem of large concentration polarization impedance of anode-supported direct carbon solid oxide fuel cell(DC-SOFC),tubular cone-shaped anode-supported segmented-in-series solid oxide fuel cell(SOFC)was prepared by an improved gel-casting method.By appropriately increasing content of the solvent,fluidity of the slurry and quality of the obtained product were improved.By increasing content of the pore-forming agent,the porosity of the anode was increased,reducing the diffusion resistance of gas.As-improved SOFC was fueled by hydrogen and operated at 800 ℃ with an open-circuit voltage of 1.05 V.The polarization impedance of the electrochemical impedance spectrum decreased while the maximum power density was 0.67 W·cm-2 and the active area of the cathode was 2.2 cm2.These SOFC electrochemical performances were significantly higher than that before improvement.Activated carbon loaded on the anode with 5%(in mass)K as catalyst was directedly used as the fuel of SOFCs.Using this anode-supported direct carbon,the DC-SOFC was prepared,showing an open circuit voltage of 1.030 V and a peak power density of 0.74 W·cm-2 at 800 ℃.This DC-SOFC was discharged at a constant current of 400 mA,and its effective utilization rate of carbon fuel was 31%which was higher than that before improvement(17%).Four improved tubular cone-shaped single cells were connected in series to form a four-cell stack,showing a peak power of 8.0 W and a corresponding power density of 0.91 W·cm-2 at 800 ℃,which was higher than that before improvement(4.1 W),exceeding the maximum of previous reported DC-SOFC,and displayed an effective utilization rate of 15%for carbon fuel.
direct carbon solid oxide fuel cellgel-castingBoudouard reactiontubular cone-shaped segmented-in-seriespotassium catalyst