摘要
针对阳极支撑型直接碳固体氧化物燃料电池(DC-SOFC)的浓差极化阻抗大的问题,本研究采用改进后的凝胶注模法制备了阳极支撑型锥管状固体氧化物燃料电池(SOFC).通过适当增加溶剂的含量,改善了浆料的流动性,提高了成品的质量;通过增大造孔剂的含量,提高了阳极的孔隙率,减小了气体的扩散阻力.改进后的SOFC以氢气为燃料,在800 ℃运行时,开路电压为1.05 V,电化学阻抗谱的极化阻抗更小,电池的最大功率密度为0.67 W·cm-2(阴极有效面积为2.2 cm2),明显优于改进前的SOFC.改进后的SOFC直接采用担载质量分数5％K的活性炭为燃料,在800 ℃运行时,开路电压为1.030 V,接近理论电压,最大功率密度达0.74 W·cm-2,以400 mA进行恒流放电,碳燃料的有效利用率为31％,高于改进前电池的碳燃料的有效利用率17％.将改进后的4个锥管状单电池串联成电池组,直接采用担载质量分数5％K催化剂的活性炭为燃料,在800 ℃运行时,最大功率达8.0 W,高于改进前的4节DC-SOFC电池组(4.1 W),该电池组碳燃料的有效利用率为15％,峰值功率密度可达0.91 W·cm-2,超过了文献报道的最高值.
Abstract
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.
维普
万方数据