Pseudo-Steady State of High-frequency Resistance for Polymer Electrolyte Membrane Fuel Cell: Effect of In-Plane Heterogeneity

Abstract

High frequency resistance (HFR) has become the most important input signal for the on-board water management of polymer electrolyte membrane fuel cell (PEMFC) vehicles in practical applications, due to its close physical relation to the membrane water content. However, according to our latest experimental result, the paradox arises that HFR reaches a steady state regardless of continuous reduction in membrane water content, in other words, the pseudo-steady state of HFR is achieved. To investigate the triggering mechanism, for the first time, we combine current mapping technique with image difference technique to observe dynamic evolution of current in-plane distribution, and, furthermore, to analyze membrane water distribution. We can demonstrate that, the heterogeneity of membrane water in-plane distribution triggers the pseudo-steady HFR, and it can be distinguished by the distributed monitoring, to avoid the potential failure of water management.