Abstract
Abstract A single cell of direct methanol fuel cell (DMFC) typically delivers an electrical potential between 0.5 and 1 V; thus DMFCs are assembled in parallel to meet power demands (1–5 kW). Bipolar plates (BPs) are the primary components connecting a single cell to the adjacent cells so that they provide optimum electrical conductivity. The objective of this research is to reduce the volume resistance of BPs made from a polypropylene/carbon composite by utilizing a metal insert technique. A major obstacle when it comes to molding composite plates inserted by a thin metal sheet is the delamination of material layers after the cooling process. The delamination issue is due to different surface polarities between metal and polypropylene-composite surfaces. One of the strategies to solve this issue is to modify the surface of one layer for creating similarity of the surface polarity. A metal sheet surface was coated with graphene using a cold spraying technique to enhance adhesion ability. The suitable spraying conditions were determined by experimenting with varying temperature, pressure, graphene quantity and graphene types. The effectiveness of surface modification by the graphene spraying technique was assessed by a surface morphology observation, an electrical conductivity measurement and DMFC performance tests. Results were interesting, they indicated that when DMFC was assembled with silver sheet, inserted BPs provided 25.13 mW/cm2 of power density, 3,350.7 mWh of generated energy and 67% of efficiency. This highlights that the performance of a BP prototype is superior to the performance of a commercial composite bipolar plate.
Highlights
To achieve the desired voltage and current, single fuel cells are typically connected in combination (Figure 1A)
The performance of the direct methanol fuel cell (DMFC) assembled with silver insert Bipolar plates (BPs) was superior to the performance of the DMFC assembled with commercial epoxy composite BPs, but it was still inferior compared to the performance of a cell that utilized commercial graphite BPs
Calculations of BP amount requirement for stack making were based on the assumption that the same specification of a DMFC stack was used in all cases, and the DMFC stack operation acquired the same losses
Summary
To achieve the desired voltage and current, single fuel cells are typically connected in combination (Figure 1A). The manifold transfers the reactant gases to the active areas while gathering the unreacted reactants and products of the redox reactions In this type of DMFC stack system, electrons must transfer through BPs to complete an electrical circuit. Most of the polymer composite BPs are carbon–polymer composites that are created by incorporating a carbonaceous material into a polymer binder Both thermoplastic and thermosetting have been used to fabricate BPs [3]. The resins can be highly crosslinked through a proper curing process, and the crosslinked structure provides good chemical resistance Thermoplastic, such as polypropylene (PP), polyethylene (PE), poly (vinylidene fluoride) (PVDF), liquid crystalline polymer (LCP), poly (phenylene sulfide) (PPS), and fluoropolymer [5], have been used less in BP fabrication than
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
