Voltammetric and galvanostatic methods for measuring hydrogen crossover in fuel cell
Sida Li, Xuezhe Wei, Haifeng Dai, Hao Yuan, Pingwen Ming
Abstract
Hydrogen crossover rate is an important indicator for characterizing the membrane degradation and failure in proton exchange membrane fuel cell. Several electrochemical methods have been applied to quantify it. But most of established methods are too rough to support follow-up applications. In this paper, a systematic and consistent theoretical foundation for electrochemical measurements of hydrogen crossover is established for the first time. Different electrochemical processes occurring throughout the courses of applying potentiostatic or galvanostatic excitations on fuel cell are clarified, and the linear current-voltage behavior observed in the steady-state voltammogram is reinterpreted. On this basis, we propose a modified galvanostatic charging method with high practicality to achieve accurate electrochemical measurement of hydrogen crossover, and the validity of this method is fully verified. This research provides an explicit framework for implementation of galvanostatic charging method and offers deeper insights into the principles of electrochemical methods for measuring hydrogen crossover.