固体氧化物燃料电池堆的稳定工况特性

以大面积电池和千瓦级电堆为对象,研究了温度、燃料成分、流量等对阳极支撑型电堆性能的影响。结果表明:温度的影响最大,复数阻抗谱中高频弧对应的活化能最高;欧姆阻抗的活化能较低,表明其不全是离子电导的电阻,还包括双极板的表面电阻和可能的接触电阻。利用干氢气燃料测试时,在开路电压附近表现出较大的活化极化,且其活化能很小,表明该活化极化的速率控制步骤并非是电荷转移过程,而是对应某种表面扩散过程。模拟重整气燃料测试过程中活化极化不明显,但开路电压较低,性能比氢气燃料差。随着电堆工作电流的增加,燃料尾气的温度增加,表现出明显的热效应。

Performance of Solid Oxide Fuel Cell and Stack for Stable Operation

Effects of temperature, fuel composition and flow rate on the performance of an anode-supported cell and a stack were studied. The results show that in the complex impedance spectrum, the activation energy corresponding to high frequency arc is the highest;that of the Ohmic loss is lower, which indicates that not only the ionic conductivity resistance, but also the surface resistance and possible contact resistance are included. With dry hydrogen as fuel, the results show that the activation polarization near the open circuit voltage is large and the activation energy is very small, which indicates that the rate control step of the activation polarization is not a charge transfer process, but a surface diffusion process. For simulated reforming gas fuels, the results show the activation polarization is small, but the open circuit voltage is lower, so that the performance is worse than that of hydrogen fuel. With the increase of the stack current, the temperature of the fuel exhaust gas increases, showing obvious thermal effect.