摘要
固体氧化物燃料电池的翘曲会影响电极-盖板界面的接触情况,从而影响电化学性能,对相关制造工艺提出了很大的挑战.为了分析燃料电池平面度对放电过程的影响,揭示其潜在的风险,我们建立了两个基于有限元法的仿真模型,对考虑平面度缺陷的燃料电池封装和放电进行分析.在对固体氧化物燃料电池进行平面度测量的基础上,首先建立了具有真实燃料电池翘曲特性的几何模型,分析封装过程中接触压力的分布情况.然后将接触电阻的仿真结果导入到三维多物理场耦合模型中,模拟具有平面度缺陷的燃料电池电化学性能.计算结果展示了燃料电池两侧封装过程中接触压力的分布情况.通过对比有接触电阻和无接触电阻的燃料电池电流密度,分析了电池与盖板的接触对放电过程的影响.结果表明,燃料电池的凹陷面较难达到满意的接触状态,需要比凸起面更大的封装压力.燃料电池表面接触电阻的变化将引起电流传导路径的变化,产生局部高电流或低电流.这项工作强调了在燃料电池中保持均匀分布的接触电阻的重要性,为今后的优化工作奠定了基础.
The warpage of solid oxide fuel cells can influence the component contact in electrode-interconnect plate interface and thus the electrochemical performance, posing a considerable challenge to the related manufacturing technologies. To analyse the impact of fuel cell flatness on the discharge process and to reveal its potential risk, two simulation models based on the finite element method are built to analyze the packaging and discharging of fuel cells considering the flatness defect. Based on the flatness measurement of solid oxide fuel cells, a geometry with real fuel cell warping characteristics is first built to analyze the distribution of the contact pressure during the packaging process. Then the simulation results of contact resistance are imported into a 3 D multi-physical coupled model to simulate the electrochemical performance of a fuel cell with flatness defect. The distribution of contact pressure during packaging on either side of the fuel cell is demonstrated. By comparing the current densities of fuel cells with and without contact resistance, the influence of contact state on the current density is analyzed. The results show that the concave surface of the fuel cell is harder to reach a satisfactory contact state, which needs a higher packaging force than the convex surface. The variation of the contact resistance on the fuel cell surface will induce the change of electrical current paths and generate local high or low current. This work emphasizes the importance of maintaining an evenly distributed contact resistance in fuel cells and lays the foundation for future optimization.
作者
谷宇晨
蒋聪盈
官万兵
仲政
GU Yuchen;JIANG Congying;GUAN Wanbing;ZHONG Zheng(School of Aerospace Engineering and Applied Mechanics,Tongji University,Shanghai 200092,China;Ningbo Institute of Material Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,Zhejiang,China;School of Science,Harbin Institute of Technology(Shenzhen),Shenzhen 518055,Guangdong,China)
出处
《力学季刊》
CSCD
北大核心
2020年第3期410-418,共9页
Chinese Quarterly of Mechanics
基金
国家重点研发计划(2018YFB1502600)
国家自然科学基金(11772106,11932005)。
关键词
燃料电池
数值模拟
多场耦合
平面度
solid oxide fuel cell
numerical simulation
multi-physical coupling
flatness
