Improvement of Electrode Performance on the Alkali Metal Thermal to Electric Converter

提出并讨论了用于碱金属热电转换器(AMTEC)的微米级集流引线。集电流引线直接沉积在固体β“氧化铝电解液的阴极侧表面上，消除了对传统捆绑金属网的需要。新型集流引线还降低了AMTEC装置阴极侧电极的电阻和传质阻力。钠在多孔电极中的传质特性对AMTEC循环的输出性能有很大影响。在AMTEC循环中，电极电阻和多孔电极与集电体之间的接触电阻也会导致功率输出显著降低。为了提高整体性能，必须同时提高传质和电阻。微米级的电流引线有可能通过…降低整体电阻新研制的钠暴露测试电池(SETC)用于测量多孔钼电极的传质特性。对所测得的性能进行了检验，并提出了电极上的传质模型。另一方面，对引线的电学特性进行了实验检测。采用Ar激光诱导热化学气相沉积方法，线性沉积了钼电流引线。研究了压力、激光功率、写入速度等沉积条件对引线宽度和厚度的影响。还测量了电极的电阻，测得的体积电阻是块状钼的4-6倍，并对测量数据进行了分析。计算了包括最佳宽度、距离和厚度在内的各种构型。将直接沉积电流引线的电极性能与传统绑扎集电极的性能进行了比较，结果表明，即使在低体积电阻的情况下，其功率密度仍可提高约35%。验证了本研究提出的现有引线结构的有效性。如果沉积引线的体积电阻能够得到改善，这种方法有望获得更高的性能。较少

Micron-scale current collection leads for the Alkali Metal Thermal to Electric Converter (AMTEC) have been proposed and discussed in this study. The current collection leads are directly deposited on cathode side surfaces of the solid beta"-alumina electrolyte to eliminate the necessity for the conventional tied-on metal meshes. The new current collection leads also reduce electrical and mass transfer resistance in the cathode side electrodes of the AMTEC devices.The mass transport characteristics of sodium through the porous electrode strongly influence the output performance of the AMTEC cycle. Electrode electrical resistance and contact resistance between the porous electrode and the current collector also cause significant lowered power output in the AMTEC cycle. In order to improve the overall performance, both mass transport and electrical resistance must be improved simultaneously. The micron-scale current leads have a possibility to lower the overall electrical resistance with … More small increase in the mass transport resistance.The sodium exposure test cell (SETC) was newly fabricated and used to measure the mass transfer characteristics in the porous molybdenum electrode. The measured performance was examined and a mass transport model on the electrodes was introduced. On the other hands, the electrical characteristics of the leads were experimentally examined. The current leads of molybdenum were linearly deposited by Ar laser-induced thermal CVD method. The influence of depositing conditions, such as pressure, laser power, and writing speed, on the formed width and thickness of the leads was examined. The electrical resistance was also measured and the measured volumetric resistance of the deposited leads was 4-6 times as high as that of the bulk molybdenum.The analysis based on the measured data was also conducted. Various configurations include optimum width, distance and thickness were calculated. Compared result of the electrode performance having direct deposited current leads with that of the conventional tied-on collector has shown that its power density is about 35% higher even with its low electrical volumetric resistance. The effective of the current lead structure proposed in this study was verified. If the volumetric resistance of the deposited leads can be improved, much higher performance is expected with this method. Less