Formation of Membrane Electrode Assembly for High Temperature Methanol Fuel Cells

2015 ◽  
Vol 645-646 ◽  
pp. 1175-1180 ◽  
Author(s):  
Da Zhi Wang ◽  
Xiao Hu Zhu ◽  
Wen Zha ◽  
Tong Qun Ren ◽  
Ming Qiang Li ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
High Temperature ◽  
Flow Rate ◽  
Proton Exchange Membrane ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Layer By Layer ◽  
Catalyst Layers

In this work, a quaternized polysulfone/PTFE/H3PO4composite membrane was prepared and used to a high temperature sustainable proton exchange membrane (HTPEM). This HTPEM was prepared based on a porous PTFE membrane, which can sustainable for 200 °C. Pt/C nano-suspension was prepared and deposited layer-by-layer on the gas diffusion layer (GDL) using electrohydrodynamic atomization (EHDA) deposition technique for the formation of cathode and anode catalyst layers (CLs). The CLs presented well packed and porous features. This EHDA deposited cathode and anode CLs, GDL and HTPEM were assembled to a membrane electrode assembly (MEA) and high temperature methanol fuel cell (HTMFC). The results showed that low concentration and high flow rate of methanol aqueous solution led to the loss of phosphoric acid on HTPEM, which resulted in the decline of the HTPEM. When the concentration and the flow rate of the methanol aqueous solution was increased and reduced, respectively, the cell can work properly at a temperature of 170 °C.

scholarly journals Structures of Membrane Electrode Assembly Catalyst Layers for Proton Exchange Membrane Fuel Cells

2012 ◽  
Vol 5 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Tzyy-Lung Leon Yu ◽  
Hsiu-Li Lin ◽  
Po-Hao Su ◽  
Guan-Wen Wang
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Catalyst Layers ◽  
Black Layer ◽  
Exchange Membrane ◽  
Pt Black

In this paper, we modify the conventional 5-layer membrane electrode assembly (MEA, in which a proton exchange membrane (PEM) is located at its center, two Pt-C-40 (Pt on carbon powder support, Pt content 40 wt.%) catalyst layers (CLs) are located on the surfaces of the both sides of the PEM and two gas diffusion layers (GDLs) are attached next on the outer surfaces of two Pt-C-40 layers) and propose 7-layer and 9-layer MEAs by coating thin Pt-black CLs at the interfaces between the Pt-C-40 layer and the GDL and between the PEM and the Pt-C-40 layer and reducing the Pt-C-40 loading. The reduced Pt loading quantity of the Pt-C-40 layer is equal to the increased Pt loading quantity of the Pt-black layer, thus the total amount of Pt loadings in the unmodified conventional MEA and the modified MEAs are at a fixed Pt loading quantity. These modified MEAs may complicate the manufacture process. The main advantage of these 7- and 9-layer MEAs is the thinner CL thickness and thus lower CL proton transport resistance. Because of the thin Pt-black layer thickness in MEA, we avoid agglomeration of the Pt-black particles and maintain high Pt catalytic activity. We show these new CL structure MEAs have better fuel cells performance than the conventional 5-layer MEA.

Synthesis and Performance Evaluation of an S-POSS Based PBI Electrolyte for High Temperature PEM Fuel Cell Applications

2016 ◽  
Author(s):  
Susanta K. Das ◽  
K. J. Berry
Keyword(s):  
High Temperature ◽  
Proton Exchange Membrane ◽  
Tensile Modulus ◽  
Membrane Electrode Assembly ◽  
Weight Percent ◽  
Degree Of Polymerization ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Ambient Conditions ◽  
Reaction Solution

In this paper, using patented nano-additive based polymer synthesis technology, a novel approach to the design and fabrication of high temperature proton exchange membrane (PEM) has been developed. The presence of sulfonated octaphenyl POSS (S-POSS) in a PBI-PA (polybenzimidazole-phosphoric acid) membrane results in a 40–50% increase in conductivity at 120–200$deg relative to non-sulfonated silica or POSS control fillers at comparable weight percent filler loadings and PBI molecular masses, and also relative to unfilled PBI-PA membranes. In addition, the presence of S-POSS and silica both result in physical reinforcement of the membrane and increased its modulus and mechanical integrity, but only S-POSS offers the benefits of both increased conductivity and increased modulus. Isophthalic acid and 3,3’-diaminobenzidine (DAB) were polymerized in the presence of polyphosphoric acid (PPA) and S-POSS nanoadditive, and the degree of polymerization was monitored by viscosity and torque change measurements. Molecular mass was determined by inherent viscosity measurements of samples removed from the reaction solution. Membranes were prepared by casting the reaction solution and allowing PPA to hydrolyze to PA under ambient conditions. The membranes were characterized for acid content, in-plane conductivity, tensile modulus and shear modulus, and were roll-milled to achieve the desired thickness for membrane electrode assembly (MEA) fabrication.

Roll-to-roll stack and lamination of gas diffusion layer in multilayer structured membrane electrode assembly

2019 ◽  
Vol 234 (1-2) ◽  
pp. 66-74
Author(s):  
Jiankui Chen ◽  
Xi Jiang ◽  
Wei Tang ◽  
Liang Ma ◽  
Yiqun Li ◽  
...  
Keyword(s):  
Diffusion Layer ◽  
Proton Exchange Membrane ◽  
Gas Diffusion Layer ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Roll To Roll ◽  
Multilayer Membrane ◽  
Exchange Membrane

A membrane electrode assembly is the core component of a proton-exchange membrane fuel cell stack. It consists of multilayer structured membranes which are flexible, heterogeneous and have variable cross section. To improve the efficiency of membrane electrode assembly processing and manufacturing, a roll-to-roll system with gas diffusion layer is designed. By peeling the protective membrane and the upper and lower gas diffusion layers’ hot-pressing, proton-exchange membrane is manufactured into a five-layer catalyst-coated membrane. Then, the catalyst-coated membrane is manufactured into membrane electrode assembly by multilayer membrane breakpoint die-cutting and laying-off. The system integrates multiple key technologies, including roll-to-roll precise feeding, gas diffusion layer multi-degree accurate operation and multichannel temperature control, to realize the precise positioning of flexible multilayer membrane and brittle gas diffusion layer. The tension inhomogeneity and critical wrinkling tension are modeled for web traveling in the continuous roll-to-roll manufacturing equipment. The proposed roll-to-roll stack and lamination system effectively combines discontinuous hot-pressing, die-cutting, laying-off technics to realize the high-efficiency manufacturing of membrane electrode assembly.

Proton Exchange Membranes Based on Blends of Poly(Benzimidazole) and Butylsulfonated Poly(Beznimidazole) for High Temperature PEMFC

2010 ◽  
Author(s):  
Hsiu-Li Lin ◽  
Chih-Ren Hu ◽  
Po-Hao Su ◽  
Yu-Cheng Chou ◽  
Che-Yu Lin
Keyword(s):  
High Temperature ◽  
Hydrogen Bonds ◽  
Phosphoric Acid ◽  
Doping Level ◽  
Proton Exchange Membrane ◽  
Membrane Electrode Assembly ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Exchange Membrane

Phosphoric acid doped poly(benzimidazole) (PBI) is one of excellent candidates of proton exchange membranes for high temperature (150–180°C) proton exchange membrane fuel cells (PEMFCs). However, the strong inter-polymer hydrogen bonds cause low elongation and brittleness of PBI membranes. In this work, we synthesize poly(benzimidazole) (PBI) and butylsulfonated poly(benzimidazole) (PBI-BS), in which around 22 mole% of imidazole –NH groups of PBI are grafted with sulfonated butyl groups. We show the elongation, phosphoric acid doping level, and proton conductivity of PBI can be improved by blending ∼ 20 wt% of PBI-BS in the PBI membrane, and the membrane electrode assembly prepared from PBI/PBI-BS (8/2 by wt) blend membrane has a better PEMFC performance at 140°C ∼ 180°C than that prepared from PBI membrane. It is believed that the crosslink interactions of imidazole -NH and -N=C-groups with side chain –C4H8−SO3H groups of PBI-BS reduces the inter-PBI hydrogen bonds and increases the free volume of polymers, which leads to the enhancements of the membrane toughness and phosphoric acid doping level and the PEMFC performance.

Sign in / Sign up

Export Citation Format

Share Document