TY - JOUR A1 - Tötzke, C. A1 - Manke, I. A1 - Hartnig, C. A1 - Kuhn, R. A1 - Riesemeier, Heinrich A1 - Banhart, J. T1 - Investigation of carbon fiber gas diffusion layers by means of synchrotron X-ray tomography JF - ECS transactions N2 - The 3-dimensional spatial distribution of liquid water in different gas diffusion layer (GDL) materials was analyzed using synchrotron X-ray tomography. The capability of the method was demonstrated by virtually separating the GDL components in order to facilitate individual analysis of fiber material, liquid water and gas filled pore spaces. The influence of hydrophobic surface treatment on the water distribution in the GDL was illustrated by analyzing three GDL materials with different degrees of hydrophobicity. In the least hydrophobic sample, liquid water tends to form larger clusters which stretch out about several hundred µm inside the porous GDL. In contrast, only small water clusters were found in the strongly hydrophobic material with high Polytetrafluoroethylene (PTFE)-content as the liquid is partially pressed out of the GDL. Additionally, the influence of fiber orientation on the water distribution in the felt material was demonstrated. KW - Synchrotron X-ray tomography KW - Fuel cell KW - Gas diffusion layer (GDL) materials KW - Analysis of fiber material PY - 2011 DO - https://doi.org/10.1149/1.3635571 SN - 1938-6737 SN - 1938-5862 VL - 41 IS - 1 SP - 379 EP - 386 CY - Pennington, NJ, USA AN - OPUS4-25348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Grothausmann, R. A1 - Arlt, Tobias A1 - Manke, I. T1 - High quality reconstruction of insufficient tomographic data by a new iterative procedure T2 - 18th WCNDT - World conference on nondestructive testing (Proceedings) N2 - In order to demonstrate the challenging tasks in current R&D applications in the field of renewable energy sources experimental neutron and electron tomographic data sets of PEM fuel cell components are processed by an advanced version of the DIRECTT algorithm. The neutron measurements of the water distribution suffer from several intrinsic limitations such as massive position dependent focal smearing due to the large primary neutron beam aperture. Electron (TEM) tomography allows characterisation of nanometre sized catalyst particles but is hampered by the following restrictions: partial opacity, a limited sector of projections (missing wedge), very few projections, samples exceeding the detector size (region of interest) and improper angular alignment. Beyond the capabilities of other algorithms DIRECTT proves to overcome these essential reconstruction problems, in comparison to FBP and SIRT. Nevertheless, careful data pre-processing is an inevitable requirement in order to fully exploit the algorithm's potentials. T2 - 18th WCNDT - World conference on nondestructive testing CY - Durban, South Africa DA - 2012-04-16 KW - Iterative reconstruction KW - DIRECTT KW - Neutron tomography KW - Electron tomography KW - Focal smearing KW - Limited View KW - Opacity KW - Fuel cell KW - Renewable energy PY - 2012 UR - http://www.ndt.net/article/wcndt2012/papers/207_wcndtfinal00207.pdf SN - 978-0-620-52872-6 SP - 1 EP - 8(?) AN - OPUS4-25833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Trogadas, P. A1 - Cho, J. I. S. A1 - Rasha, L. A1 - Lu, X. A1 - Kardjilov, N. A1 - Markötter, Henning A1 - Manke, I. A1 - Shearing, P. R. A1 - Brett, D. J. L. A1 - Coppens, M. O. T1 - A nature-inspired solution for water management in flow fields for electrochemical devices JF - Energy & Environmental Science N2 - A systematic, nature-inspired chemical engineering approach is employed to solve the issue of flooding in electrochemical devices. The mechanism of passive water transport utilized by lizards living in arid environments is leveraged to design flow-fields with a microchannel structure on their surface, through which capillary pressure rapidly removes the water generated in the electrochemical device. This water management strategy is implemented in proton exchange membrane fuel cells (PEMFCs) with a lunginspired flow-field, which ensures uniform distribution of reactants across the catalyst layer. Jointly, this nature-inspired approach results in flood-free, stable operation at 100% RH and a B60% increase in current (B1.9 A cm-2) and peak power density (B650 mW cm−2) compared to current PEMFCs with a flood-prone, serpentine flow-field (B0.8 A cm-2 and 280 mW cm-2, respectively). This significant advance allows for PEMFC operation at fully humidified conditions. KW - Neutron imaging KW - X-ray tomography KW - Fuel cell PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596662 DO - https://doi.org/10.1039/d3ee03666a VL - 17 SP - 2007 EP - 2017 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -