An analysis of the imperfections and defects inside composite bipolar plates using X-Ray computer tomography and resistivity simulations. (21st July 2021)

• Record Type: Journal Article
• Authors: Sietmann, Michael; Janßen, Holger; Müller, Martin; Lehnert, Werner
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 50(2021)
• Page Start: 25677
• Page End: 25688
• Publication Date: 2021-07-21
• Subjects: Bipolar plate -- Imperfections -- Defects -- X-ray computer tomography -- Resistivity simulation; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.05.078
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: With the increasing mass production, the quality control of bipolar plates (BPPs) becomes more important. A classification and understanding of imperfections and defects is necessary for the design of quality assurance measures within the manufacturing process. In this paper, a combined X-Ray computer tomography (CT) and resistivity simulation approach is used to investigate graphite composite BPPs. With this non-destructive approach, the morphology and composition of a detailed BPP section, as well as an entire flow field, can be analyzed for its characteristics and defects. The different detected imperfections occurring in injection-molded and compression-molded BPP samples include cracks, air bubbles and agglomerations of voids and foreign particles. The investigated flow field geometry has a major impact and increases the electrical resistance by about 19% compared to a bulk material body. The investigated imperfections inside the BPP material have a minimal impact on the electrical resistance of the BPP. Graphical abstract: Image 1 Highlights: X-Ray computer tomography reveals the inner structure of composite bipolar plates. Cracks, air bubbles and agglomerations of foreign particles detected inside BPP. Imperfections inside BPP have minimal impact on the electric properties. The flow field has a major impact on the electrical resistance of composite BPP.