Research on membrane electrode assembly consistency of high-power proton exchange membrane fuel cell stack

With the continuous increase of the application fields and scale of fuel cells, there is a growing demand for high-power fuel cell stacks. The voltage consistency of high-power fuel cell stacks is an important indicator to measure or affect the performance of the stack. In this paper, the single-cell voltage consistency of a 65 kW high-power stack produced by a certain company was studied, the influence of various operating conditions on stack consistency was investigated, and the possible reasons causing consistency problems were deeply analyzed and discussed. It is showed that the stack exhibited good consistency under rated power and its given operating conditions. The output power of the stack, stack operating temperature and temperature range, reactant gas stoichiometry, gas humidity, and other factors all have impact on the voltage consistency of the stack. Among them, the output power, air stoichiometry, and gas humidity dramatically influenced on cell consistency most significantly, and an increase in output power, a decrease in air stoichiometry and air humidity will greatly reduce the stack consistency. On the basis of the research results, suggestions on operating conditions for maintaining the consistency of high-power fuel cell stacks were put forward in this paper. This work is of great significance for improving the design and optimizing the operating conditions of high-power stacks, and promoting the development of fuel cell technology and industry in China. © 2024 Materials China. All rights reserved.