Enhanced performance of polybenzimidazole-based high temperature proton exchange membrane fuel cell with gas diffusion electrodes prepared by automatic catalyst spraying under irradiation technique

Abstract

Su, H. et al. (2013). Enhanced performance of polybenzimidazole-based high temperature proton exchange membrane fuel cell with gas diffusion electrodes prepared by automatic catalyst spraying under irradiation technique. Huaneng Su, Sivakumar Pasupathi, Bernard Jan Bladergroen, Vladimir Linkov and Bruno G. Pollet Abstract Gas diffusion electrodes (GDEs) prepared by a novel automatic catalyst spraying under irradiation (ACSUI) technique are investigated for improving the performance of phosphoric acid (PA)-doped polybenzimidazole (PBI) high temperature proton exchange membrane fuel cell (PEMFC). The physical properties of the GDEs are characterized by pore size distribution and scanning electron microscopy (SEM). The electrochemical properties of the membrane electrode assembly (MEA) with the GDEs are evaluated and analyzed by polarization curve, cyclic voltammetry (CV) and electrochemistry impedance spectroscopy (EIS). Effects of PTFE binder content, PA impregnation and heat treatment on the GDEs are investigated to determine the optimum performance of the single cell. At ambient pressure and 160 o C, the maximum power density can reach 0.61 W cm -2 , and the current density at 0.6 V is up to 0.38 A cm -2 , with H /air and a platinum loading of 0.5 mg cm -2 on both electrodes. The MEA with the GDEs shows good stability for fuel cell operating in a short term durability test.

Hydrogen and Fuel Cell Technologies at the Hydrogen South Africa (HySA) Systems Competence Centre

“…Through a modular design and standardised interfaces the 'HySA Power Module' will be designed so that it can be retro-fi tted into existing small battery-powered vehicles with minimal changes to the vehicle itself. MEA performances comparable to the best results reported so far have been achieved under similar conditions (3). The GDEs in this case were prepared by a novel automatic catalyst spraying under irradiation technique, at usual operating conditions (160ºC, H 2 /air, ambient pressure).…”

“…The main reason for the performance was found to be the preparation conditions of the MEA and is reported elsewhere (3). Another crucial factor for the MEA, apart from the performance, is its durability under standard operating conditions.…”

Eliminating micro-porous layer from gas diffusion electrode for use in high temperature polymer electrolyte membrane fuel cell

“…Surprisingly, the GDE shows excellent stability for more than 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 22 hydrophobic than a MPL due to the higher PTFE content (25 wt.% vs. 15 wt.%), which could repel any mobile PA from the membrane, thus a high PA doping level was maintained in the membrane. Furthermore, the well-distrusted PTFE network in the CL is highly hydrophobic, which can hold the impregnated PA, thereby the leaching of PA could be reduced and abundant triple-phase boundaries (TPBs) were also well maintained in the CLs [11]. Second, the elimination of MPL greatly decreased the amount of micro pores in the GDE, resulting in an inferior capillarity, which reduced the wicking of PA from the CL, thereby, the PA loss.…”

“…This type of HT-PEMFCs can normally operate between 150 o C - 200 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 4 gas diffusion layer (GDL) instead of the membrane. Therefore, for HT-PEMFC the preparation of GDE is very important as it is the only place where electrochemical reactions occur, for which a decent inner structure should be established for smoothly transporting the reactant gases/produced water to/from the CL [11,12]. Normally, the GDE was structured with three layers, as illustrated in Fig.…”

Uptake of protic electrolytes by polybenzimidazole-type polymers: absorption isotherms and electrolyte/polymer interactions

“…Due to a very high softening, high decomposition temperatures and an exceptional thermal and chemical stability, polybenzimidazole polymers are used in high-performance and special-purpose applications. This includes their use as a proton-conducting electrolyte in polymer membrane fuel cells for high operating temperatures (HT-PEFC) [4][5][6].…”