Towards ultra-fast X-ray Tomographic Microscopy of Liquid Water in PEFC

Synchrotron radiation X-ray tomographic microscopy (SRXTM) allows the simultaneous in-situ visualization of the water and carbonaceous structures in the gas diffusion layer (GDL) of polymer electrolyte fuel cells (PEFC) on the pore scale. Recently, the TOMCAT beamline of the Swiss Light Source (SLS) was upgraded with a new CMOS camera, enabling ultra fast in-situ XTM investigations of PEFC with temporal resolution of about 8 s. This acquisition speed limits irradiation of the cell, preventing radiation damage and subsequent measurement bias. In this way, PEFC can be imaged several times before deterioration is arising. The stability of the 3D liquid water distribution in porous GDL structures was studied with a temporal resolution of 10 minutes and liquid water fraction data is presented.