Design of 3-electrode system for in situ monitoring direct methanol fuel cells during long-time running test at high temperature

• Published in: Applied energy Vol. 197; pp. 163 - 168
• Main Authors: Liu, Guicheng, Li, Xinyang, Wang, Hui, Liu, Xiuying, Chen, Ming, Woo, Jae Young, Kim, Ji Young, Wang, Xindong, Lee, Joong Kee
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-07-2017
• Subjects: 3-Electrode system; Direct methanol fuel cell; High temperature; Life test; Solution-type reference electrode; 3-Electrode system; High temperature; Direct methanol fuel cell; Life test; Solution-type reference electrode
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2017.04.016

•A design of a 3-electrode system with a solution-type salt bridge is reported.•In situ monitoring is realized for DMFC long-time running test at high temperature.•Effect of temperature and running time on anodic and cathodic polarizations are analyzed.•Effect of temperature on cathodic performance is more significant than that of anode.•Performance attenuation mainly comes from anode during long-time running at 80°C.
To understand the effect mechanisms of long-time running and high operation temperature on performance of the direct methanol fuel cell (DMFC) more clearly and directly, in this paper, a new design of 3-electrode system with a solution-type salt bridge has been developed to distinguish the integral polarization into anodic and cathodic polarizations at various temperatures and explore the attenuation mechanism by in situ monitoring the potential of anode during long-time running process at 80°C, for the first time. The results indicate that the optimized 3-electrode system consists of a standard calomel electrode (SCE) and a solution-type salt bridge placed in the anode hole filled by 0.5molL−1 H2SO4 solution. By utilization of the 3-electrode system, the effect mechanisms of the running temperature and time on electrochemical parameters of the DMFC have been found: (1) The increasing operation temperature improves cathodic performance more significantly than that of anode; (2) the attenuation of fuel cell performance mainly comes from that of anode during the 20-h running test at 80°C, resulting from the sharp drop of electrochemical active surface area of anode. More important, the new 3-electrode system has simplified the detection equipment and reduced the operating difficulty in a practical application for DMFCs, resulting in its portability.