沉积温度对等离子喷涂金属支撑型固体氧化物燃料电池结构及电化学性能的影响

Influence of Deposition Temperature on Structural and Electrochemical Performance of Plasma-sprayed Metal-supported Solid Oxide Fuel Cell

为提高大气等离子喷涂(APS)制备金属支撑型固体氧化物燃料电池在中低温下的输出性能,本工作采用APS在不锈钢基体上制备基于氧化钪稳定氧化锆(ScSZ)电解质的固体氧化物燃料电池,控制喷涂时的沉积温度分别为100℃、300℃和600℃,通过扫描电子显微镜(SEM)观察单个ScSZ粒子沉积状态和涂层微观形貌,并用电化学工作站测试单电池的输出性能和交流阻抗谱。结果表明,随着沉积温度升高,ScSZ沉积粒子由溅射状铺展转变为圆盘状铺展,单个粒子中的裂纹密度逐渐减小,裂纹所占面积比从9.75%降低到5.73%。组装成单电池后,电解质涂层与阳极和阴极结合良好。ScSZ涂层内部片层结合情况随沉积温度的升高而得到改善,裂纹减少且孔隙尺寸减小,涂层孔隙率从12.29%降低到7.72%。电化学测试结果表明,当沉积温度从100℃升高到600℃,电解质的欧姆电阻降低了1/2,电池的输出性能显著提升。600℃的沉积温度制备的单电池在800℃时的最大功率密度为0.998 W/cm^(2),欧姆阻抗为0.076Ω·cm^(2)。

This research aims to improve the output performance of the metal-supported solid oxide fuel cell prepared by atmospheric plasma spraying(APS).Specifically,solid oxide fuel cells based on scandia doped zirconia(ScSZ)electrolytes were deposited on stainless-steel substrates by APS.The deposition temperature during spraying was controlled to be 100℃,300℃and 600℃,respectively.The deposition states of individual ScSZ particle and the microstructures of ScSZ coatings were characterized by a scanning electron microscopy(SEM).The output performance and AC impedance spectrum of the single-cell were tested by an electrochemical workstation.The results show that with the increase of deposition temperature,ScSZ particles changed from sputtering to disc-shaped spread.The density of cracks in a single particle gradually decreased,and the area ratio of cracks reduced from 9.75%to 5.73%.After assembling into single cells,the electrolytes were well combined with the anode and cathode.In addition,the interlamellar bonding in the ScSZ coating was improved with the increasing deposition temperature.Both sizes of cracks and pores were reduced,and the porosity of the coating decreased from 12.29%to 7.72%.The electrochemical test results showed that as the deposition temperature increased from 100℃to 600℃,the ohmic resistance of the electrolyte was reduced by half,and the output performance of the cell was significantly improved.The maximum power density and the ohmic impedance of the single-cell prepared on the substrate at 600℃were 0.998 W/cm^(2)and 0.076Ω·cm^(2)at 800℃,respectively.