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Helium Ion Microscopy of proton exchange membrane fuel cell electrode structures

  • Received: 02 October 2017 Accepted: 27 November 2017 Published: 05 December 2017
  • Characterization of composite materials with microscopy techniques is an essential route to understanding their properties and degradation mechanisms, though the observation with a suitable type of microscopy is not always possible. In this work, we present proton exchange membrane fuel cell electrode interface structure dependence on ionomer content, systematically studied by Helium Ion Microscopy (HIM). A special focus was on acquiring high resolution images of the electrode structure and avoiding interface damage from irradiation and tedious sample preparation. HIM demonstrated its advantages in surface imaging, which is paramount in studies of the interface morphology of ionomer covered or absorbed catalyst structures in a combination with electrochemical characterization and accelerated stress test. The electrode porosity was found to depend on the ionomer content. The stressed electrodes demonstrated higher porosity in comparison to the unstressed ones on the condition of no external mechanical pressure. Moreover, formation of additional small grains was observed for the electrodes with the low ionomer content, indicating Pt redeposition through Ostwald ripening. Polymer nanofiber structures were found in the crack regions of the catalyst layer, which appear due to the internal stress originated from the solvent evaporation. These fibers have fairly uniform diameters of a few tens of nanometers, and their density increases with the increasing ionomer content in the electrodes. In the hot-pressed electrodes, we found more closed contact between the electrode components, reduced particle size, polymer coalescence and formation of nano-sized polymer fiber architecture between the particles.

    Citation: Serguei Chiriaev, Nis Dam Madsen, Horst-Günter Rubahn, Shuang Ma Andersen. Helium Ion Microscopy of proton exchange membrane fuel cell electrode structures[J]. AIMS Materials Science, 2017, 4(6): 1289-1304. doi: 10.3934/matersci.2017.6.1289

    Related Papers:

  • Characterization of composite materials with microscopy techniques is an essential route to understanding their properties and degradation mechanisms, though the observation with a suitable type of microscopy is not always possible. In this work, we present proton exchange membrane fuel cell electrode interface structure dependence on ionomer content, systematically studied by Helium Ion Microscopy (HIM). A special focus was on acquiring high resolution images of the electrode structure and avoiding interface damage from irradiation and tedious sample preparation. HIM demonstrated its advantages in surface imaging, which is paramount in studies of the interface morphology of ionomer covered or absorbed catalyst structures in a combination with electrochemical characterization and accelerated stress test. The electrode porosity was found to depend on the ionomer content. The stressed electrodes demonstrated higher porosity in comparison to the unstressed ones on the condition of no external mechanical pressure. Moreover, formation of additional small grains was observed for the electrodes with the low ionomer content, indicating Pt redeposition through Ostwald ripening. Polymer nanofiber structures were found in the crack regions of the catalyst layer, which appear due to the internal stress originated from the solvent evaporation. These fibers have fairly uniform diameters of a few tens of nanometers, and their density increases with the increasing ionomer content in the electrodes. In the hot-pressed electrodes, we found more closed contact between the electrode components, reduced particle size, polymer coalescence and formation of nano-sized polymer fiber architecture between the particles.


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    [1] Ren G, Ma G, Cong N (2015) Review of electrical energy storage system for vehicular applications. Renew Sust Energ Rev 41: 225–236. doi: 10.1016/j.rser.2014.08.003
    [2] Chang H, Wu H (2013) Graphene-based nanocomposites: preparation, functionalization, and energy and environmental applications. Energ Environ Sci 6: 3483–3507. doi: 10.1039/c3ee42518e
    [3] Guer TM (2013) Critical Review of Carbon Conversion in "Carbon Fuel Cells". Chem Rev 113: 6179–6206. doi: 10.1021/cr400072b
    [4] Chen Z, Higgins D, Yu A, et al. (2011) A review on non-precious metal electrocatalysts for PEM fuel cells. Energ Environ Sci 4: 3167–3192. doi: 10.1039/c0ee00558d
    [5] Gasteiger HA, Vielstich W, Yokokawa H (2009) Handbook of Fuel Cells, Chichester, England: John Wiley & Sons Ltd., 5–6.
    [6] Scofield ME, Liu H, Wong SS (2015) A concise guide to sustainable PEMFCs: recent advances in improving both oxygen reduction catalysts and proton exchange membranes. Chem Soc Rev 44: 5836–5860. doi: 10.1039/C5CS00302D
    [7] Suzuki T, Tsushim S, Hirai S (2011) Effects of Nafion® Ionomer and Carbon Particles on Structure Formation in a Proton-exchange Membrane Fuel Cell Catalyst Layer Fabricated by the Decal-transfer Method. Int J Hydrogen Energ 36: 12361–12369. doi: 10.1016/j.ijhydene.2011.06.090
    [8] Kim KH, Lee KY, Kim HJ, et al. (2010) The effects of Nafion® Ionomer Content in PEMFC MEAs Prepared by a Catalyst-coated Membrane (CCM) Spraying Method. Int J Hydrogen Energ 35: 2119–2126.
    [9] Zhao X, Li W, Fu Y, et al. (2012) Influence of Ionomer Content on the Proton Conduction and Oxygen Transport in the Carbon-supported Catalyst Layers in DMFC. Int J Hydrogen Energ 37: 9845–9852. doi: 10.1016/j.ijhydene.2012.03.107
    [10] Li W, Waje M, Chen Z, et al. (2010) Platinum Nanopaticles Supported on Stacked-cup Carbon Nanofibers as Electrocatalysts for Proton Exchange Membrane Fuel Cell. Carbon 48: 995–1003. doi: 10.1016/j.carbon.2009.11.017
    [11] Ma S, Chen Q, Jøgensen FH, et al. (2007) 19F NMR studies of NafionTM ionomer adsorption on PEMFC catalysts and supporting carbons. Solid State Ionics 178: 1568–1575. doi: 10.1016/j.ssi.2007.10.007
    [12] Andersen SM, Borghei M, Dhiman R, et al. (2014) Interaction of multi-walled carbon nanotubes with perfluorinated sulfonic acid ionomers and surface treatment studies. Carbon 71: 218–228. doi: 10.1016/j.carbon.2014.01.032
    [13] Andersen SM, Borghei M, Dhiman R, et al. (2014) Adsorption behavior of perfluorinated sulfonic acid ionomer on highly graphitized carbon nanofibers and their thermal stabilities. J Phys Chem C 118: 10814–10823. doi: 10.1021/jp501088d
    [14] Paul D, Fraser A, Pearce J, et al. (2011) Understanding the Ionomer Structure and the Proton Conduction Mechanism in PEFC Catalyst Layer: Adsorbed Nafion on Model Substrate. ECS Trans 41: 1393–1406.
    [15] Kongkanand A (2011) Interfacial Water Transport Measurements in Nafion Thin Films Using a Quartz-Crystal Microbalance. J Phys Chem C 115: 11318–11325.
    [16] Yu J, Jiang Z, Hou M, et al. (2014) Analysis of the Behavior and Degradation in Proton Exchange Membrane Fuel Cells with a Dead-ended Anode. J Power Sources 246: 90–94. doi: 10.1016/j.jpowsour.2013.06.163
    [17] Ma S, Solterbeck CH, Odgaard M, et al. (2009) Microscopy Studies on Pronton Exchange Membrane Fuel Cell Electrodes with Different Ionomer Contents. Appl Phys A-Mater 96: 581–589. doi: 10.1007/s00339-008-5050-9
    [18] Yakovlev S, Balsara NP, Downing KH (2013) Insights on the Study of Nafion Nanoscale Morphology byTransmission Electron Microscopy. Membranes 3: 424–439. doi: 10.3390/membranes3040424
    [19] Scheiba F, Benker N, Kunz U, et al. (2008) Electron Microscopy Techniques for the Analysis of the Polymer Electrolyte Distribution in Proton Exchange Membrane Fuel Cells. J Power Sources 177: 273–280. doi: 10.1016/j.jpowsour.2007.11.085
    [20] Radicea S, Oldani C, Merlo L, et al. (2013) Aquivion PerfluoroSulfonic Acid Ionomer Membranes: A Micro-Raman Spectroscopic Study of Ageing. Polym Degrad Stabil 98: 1138–1143. doi: 10.1016/j.polymdegradstab.2013.03.015
    [21] Eastcott JI, Easton EB (2014) Sulfonated Silica-based Fuel Cell Electrode Structures for Low Humidity Applications. J Power Sources 245: 487–494. doi: 10.1016/j.jpowsour.2013.07.005
    [22] Bautista-Rodríguez CM, Rosas-Paleta A, Rivera-Márquez JA, et al. (2009) Study of Electrical Resistance on the Surface of Nafion 115® Membrane Used as Electrolyte in PEMFC Technology Part I: Statistical Inference. Int J Electrochem Sci 4: 43–59.
    [23] Butler JH, Joy DC, Bradley G, et al. (1995) Low-voltage scanning electron microscopy of polymers. Polymer 36: 1781–1790. doi: 10.1016/0032-3861(95)90924-Q
    [24] Rodenburg C, Viswanathan P, Jepson MAE, et al. (2014) Helium ion microscopy based wall thickness and surface roughness analysis of polymer foams obtained from high internal phase emulsion. Ultramicroscopy 139: 13–19. doi: 10.1016/j.ultramic.2014.01.004
    [25] Notte J, Huang J (2016) The Helium Ion Microscope, In: Hlawacek G, Gölzhäuser A, Helium Ion Microscopy, Springer, 3–30.
    [26] Boden SA (2016) Introduction to Imaging Techniques in the HIM, In: Hlawacek G, Gölzhäuser A, Helium Ion Microscopy, Springer, 149–172.
    [27] Hlawacek G, Veligura V, Gastel R, et al. (2014) Helium Ion Microscopy. J Vac Sci Technol B 32: 020801.
    [28] Tintula KK, Jalajakshi A, Sahu AK, et al. (2012) Durability of Pt/C and Pt/MC-PEDOT Catalysts under Simulated Start-Stop Cycles in Polymer Electrolyte Fuel Cells. Fuel Cells 13: 158–166.
    [29] Egerton RF, Li P, Malac M (2004) Radiation damage in the TEM and SEM. Micron 35: 399–409. doi: 10.1016/j.micron.2004.02.003
    [30] Schneider R (2008) Scanning Electron Microscopy Studies of Nafion Deformation into Silicon Micro-Trenches for Fuel Cell Applications [PhD Thesis]. Princeton University, New Jersey.
    [31] Yakovlev S, Balsara NP, Downing KH (2013) Insights on the Study of Nafion Nanoscale Morphology by Transmission Electron Microscopy. Membranes 3: 424–439. doi: 10.3390/membranes3040424
    [32] Hoffman EA, Fekete ZA, Korugic-Karasz LS, et al. (2004) Theoretical and experimental X-ray photoelectron spectroscopy investigation of ion-implanted nafion. J Polym Sci Pol Chem 42: 551–556. doi: 10.1002/pola.10878
    [33] Lee J, Hwang I, Jung C, et al. (2016) Surface modification of Nafion membranes by ion implantation to reduce methanol crossover in direct methanol fuel cells. RSC Adv 6: 62467–62470. doi: 10.1039/C6RA12756H
    [34] Andersen SM, Skou E (2014) Electrochemical Performance and Durability of Carbon Supported Pt Catalyst in Contact with Aqueous and Polymeric Proton Conductors. ACS Appl Mater Interfaces 19: 16565–16576.
    [35] Andersen SM, Dhiman R, Larsen MJ, et al. (2015) Importance of Electrode Hot-Pressing Conditions for the Catalyst Performance of Proton Exchange Membrane Fuel Cells. Appl Catal B-Environ 172: 82–90.
    [36] Andersen SM, Grahl-Madsen L (2014) Understanding on Interface Contribution to the Electrode Performance of Proton Exchange Membrane Fuel Cells-Impact of the Ionomer Content. Int J Hydrogen Energ 41: 1892–1901.
    [37] Andersen SM (2016) Nano carbon supported platinum catalyst interaction behavior with perfluorosulfonic acid ionomer and their interface structures. Appl Catal B-Environ 181: 146–155. doi: 10.1016/j.apcatb.2015.07.049
    [38] Zhang S, Yuan XZ, Hin JNC, et al. (2009) A review of platinum-based catalyst layer degradation in proton exchange membrane fuel cells. J Power Sources 194: 588–600. doi: 10.1016/j.jpowsour.2009.06.073
    [39] Yu H, Roller JM, Mustain WE, et al. (2015) Influence of the ionomer/carbon ratio for low-Pt loading catalyst layer prepared by reactive spray deposition technology. J Power Sources 183: 84–94.
    [40] Reiser CA, Bregoli L, Patterson TW, et al. (2005) A reverse-current decay mechanism for fuel cells. Electrochem Solid-State Lett 8: A273–A276. doi: 10.1149/1.1896466
    [41] Vielstich W, Gasteiger HA, Yokokawa H (2009) Handbook of Fuel Cells: Advances in Electrocatalysis, Materials, Diagnostics and Durability: Part 2, Wiley-Blackwell.
    [42] Li G, Tan J, Gong J (2014) Effect of Compressive Pressure on the Contact Behavior Between Bipolar Plate and Gas Diffusion Layer in a Proton Exchange Membrane Fuel Cell. J Fuel Cell Sci Tech 11: 041009. doi: 10.1115/1.4027253
    [43] Diedrichs A, Rastedt M, Pinar FJ, et al. (2013) Effect of compression on the performance of a HT-PEM fuel cell. J Appl Electrochem 43: 1079–1099. doi: 10.1007/s10800-013-0597-3
    [44] Jeong B, Ocon JD, Lee J (2016) Electrode Architecture in Galvanic and Electrolytic Energy Cells. Angew Chem Int Ed 55: 4870–4880. doi: 10.1002/anie.201507780
    [45] Kim YS, Welch CF, Mack NH, et al. (2014) Highly durable fuel cell electrodes based on ionomers dispersed in glycerol. Phys Chem Chem Phys 16: 5927–5932. doi: 10.1039/C4CP00496E
    [46] Fultz DW, Chuang PYA (2011) The Property and Performance Differences Between Catalyst, Coated Membrane and Catalyst Coated Diffusion Media. J Fuel Cell Sci Tech 8: 041010. doi: 10.1115/1.4003632
    [47] Okur O, Karadag CL, San FJB, et al. (2013) Optimization of Parameters for Hot-Pressing Manufacture of Membrane Electrode Assembly for PEM (Polymer Electrolyte Membrane Fuel Cells) Fuel Cell. Energy 57: 574–580. doi: 10.1016/j.energy.2013.05.001
    [48] Jia S, Liu H (2012) Cold Pre-Compression of Membrane Electrode Assembly for PEM Fuel Cells. Int J Hydrogen Energ 37: 1367–13680.
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