In situ diagnostics for PEM fuel cells at the National Physical Laboratory
The UK's National Physical Laboratory (NPL) has developed a range of advanced in situ diagnostic techniques to support research into mitigation strategies for critical PEM fuel cell (PEMFC) degradation mechanisms. Recent innovations include a new reference electrode configuration that for the first time allows mapping of the electrode potential across the active area of an operating PEMFC; a novel technique for simultaneous measurement of active catalyst area in each cell in a fuel cell stack; a world-first measurement of the relative humidity profile in the gas channels of a working PEMFC; and a non-invasive thermal imaging technique for detection of hotspots. In addition to providing valuable data on performance and durability, these in situ measurement techniques are being used to validate a 3D fuel cell model under development at NPL, a powerful design optimisation tool that will be available to industry in an accessible software platform.