|Electrochemical energy converter, such as the fuel cell and the electrolyzer, can work with high efficiency and have an excellent reliability with low noise. These outstanding features of the fuel cell and the electrolyzer motivate us to utilize them as a main energy converter in the next generation. Although a part of them has been commercialized, more cost-reduction, durability and performance are required to be addressed. Against this background, our laboratory conducts R&D for the fuel cell and the electrolyzer based on the mechanical engineering approach as follows:|
As a recent topic, our team has succeeded to obtain 3D temperature distribution in a polymer electrolyte fuel cell (PEFC, PEMFC) by thin in-line thermocouples with fine positioning. It figured out that the temperature under the channel was higher than that under the rib. This result connects to the understanding of water behavior, leading to an appropriate water management. In addition, humidifier-less technique has been developed for cost-reduction for the PEFC. We built in a gas circulation and humidity recover system into a cell, with newly designed gas diffusion layer which contains both hydrophobic and hydrophilic microporous layers. These efforts will realize high performance PEFCs without humidifiers. Moreover, our electrochemical impedance spectroscopy technique helps to grasp the heat sources in the solid oxide fuel cell (SOFC) during operation. The heat sources have been formulated with thermal modeling, which can estimate temperature and current distribution in unit cell. This result is accessible for the control of thermal stress and the effective use of electrodes.