scholarly journals Electrical Conductivity and Water Effects in Phosphoric Acid Solutions for Doping of Membranes in Polymer Electrolyte Fuel Cells

2021 ◽  
Vol 25 (1) ◽  
pp. 467-478
Author(s):  
Jürgen Giffin ◽  
Fosca Conti ◽  
Carsten Korte
Keyword(s):  
Electrical Conductivity ◽  
Fuel Cells ◽  
Phosphoric Acid ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Electrical Energy ◽  
Efficient Solutions ◽  
Solid Polymer ◽  
Acid Solutions ◽  
Fuel Cell Performance

Abstract Fuel cells (FCs) are among the more efficient solutions to limit the emission of greenhouse gases. Based on the conversion of the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) into electrical energy, a typical FC produces a voltage of 0.7 V under load. The potential is highly increased by placing the cells in series to obtain a stacked cell. Among the types of FCs, the polymer electrolyte membrane FCs (PEMFCs) are developed mainly for transport applications, because of their low impact on the environment, high power density and light weight compared with other types of FCs. Phosphoric acid (H3PO4) doped polybenzimidazole (PBI) membranes are widely used as efficient electrolytes. The performance of a (high temperature, 130–200 °C) HT-PEMFC depends mainly on the amount of H3PO4 in the solid polymer membrane. The strong autoprotolysis of H3PO4 is responsible for the high proton conductivity also in the anhydrous state. In this study, the H2OH3PO4 system is investigated in the temperature range 60–150 °C with varying water vapour activity at constant atmospheric pressure. Main purpose is to gain more insights into the kinetics of the equilibria in the H2O-H3PO4 system, which influence the fuel cell performance. Density, water content, electrical conductivity and activation energy are determined by exposing H3PO4 solutions for sufficiently long periods to controlled gas atmosphere in order to reach near-equilibrium conditions. The coexistence of ortho- and pyrophosphoric acid is analysed and higher condensed species are also considered. A new setup fully made in quartz is designed and developed to mix the phosphoric acid solutions in a climate chamber. The experimental results are compared to literature data to validate the developed setup and the methodology.

scholarly journals Highly durable Pt-free fuel cell catalysts prepared by multi-step pyrolysis of Fe phthalocyanine and phenolic resin

2014 ◽  
Vol 4 (5) ◽  
pp. 1400-1406 ◽  
Author(s):  
Yuta Nabae ◽  
Mayu Sonoda ◽  
Chiharu Yamauchi ◽  
Yo Hosaka ◽  
Ayano Isoda ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Phenolic Resin ◽  
Polymer Electrolyte Membrane ◽  
Cell Performance ◽  
Cathode Catalyst ◽  
Fuel Cell Performance ◽  
Electrolyte Membrane ◽  
Fuel Cell Catalysts

A Pt-free cathode catalyst for polymer electrolyte membrane fuel cells has been developed by multi-step pyrolysis of Fe phthalocyanine and phenolic resin and shows a quite promising fuel cell performance.

scholarly journals Characterization of Effective In-Plane Electrical Resistivity of a Gas Diffusion Layer in Polymer Electrolyte Membrane Fuel Cells through Freeze–Thaw Thermal Cycles

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 145 ◽  
Author(s):  
Yanqin Chen ◽  
Chao Jiang ◽  
Chongdu Cho
Keyword(s):  
Electrical Resistivity ◽  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Gas Diffusion ◽  
Thermal Cycles ◽  
Fuel Cell Performance ◽  
Freeze Thaw ◽  
Electrolyte Membrane ◽  
Electrical Degradation

The electrical property of gas diffusion layers (GDLs) plays a significant role in influencing the overall performance of polymer electrolyte membrane fuel cells (PEMFCs). The electrical degradation performance of GDLs has not been reported sufficiently. Understanding the electrical degradation characteristics of GDLs is vital to better fuel cell performance, higher efficiency, and longer service time. This paper investigated the effective in-plane electrical resistivity of a commercial GDL by considering environmental and assembly conditions similar to those in use for the operation of PEMFCs. The effective in-plane electrical resistivity of the GDL, subjected to a series of freeze–thaw thermal cycles, was characterized to study its progressive electrical degradation with thermal cycles. Experimental results indicated that, under low compressive loads, the effective in-plane electrical resistivity of the commercial GDL showed weak anisotropy, and was greatly influenced by the transformation of carbon fiber connection in the porous layer. In particular, the thermal aging treatment on the GDL through the first 100 freeze–thaw cycles contributed a lot to its in-plane electrical degradation performance.

Minichannels in Polymer Electrolyte Membrane Fuel Cells

2004 ◽  
Author(s):  
Thomas A. Trabold
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Pem Fuel Cells ◽  
Cross Sectional ◽  
Fuel Cell Performance ◽  
Electrolyte Membrane ◽  
Electrochemical Devices ◽  
Sectional Shape

This paper provides an overview of the application of minichannels, typically on the order of 1 mm hydraulic diameter, in the design of polymer electrolyte membrane (PEM) fuel cells. In these electrochemical devices, minichannels deliver reactant hydrogen and oxygen to the anode and cathode electrodes, respectively, while transporting product water out of the cell. The channels must be designed for low pressure drop, to avoid excessive parasitic power losses from gas handling equipment. However, the channels also need to operate in a flow regime in which the overall water balance in the fuel cell can be maintained. The various aspects of minichannel design, including size and cross-sectional shape, are discussed, with particular emphasis on fuel cell water management. In addition to reviewing these fundamental aspects of minichannel design, examples are given of new experimental tools currently under development which are applied to relate channel water transport and accumulation to fuel cell performance.

Quaternized poly (ether ether ketone)s doped with phosphoric acid for high-temperature polymer electrolyte membrane fuel cells

2014 ◽  
Vol 2 (34) ◽  
pp. 13996-14003 ◽  
Author(s):  
Na Zhang ◽  
Baolong Wang ◽  
Chengji Zhao ◽  
Shuang Wang ◽  
Yurong Zhang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Phosphoric Acid ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Electrolyte Membrane ◽  
Ether Ether Ketone ◽  
Poly Ether Ether Ketone ◽  
Ether Ketone

The quaternized poly(ether ether ketone)s, which were aminated by trimethylamine, triethylamine, tripropylamine and 1-methylimidazole, were studied as alternative HTPEM materials.

A phosphoric acid-doped electrocatalyst supported on poly(para-pyridine benzimidazole)-wrapped carbon nanotubes shows a high durability and performance

2015 ◽  
Vol 3 (27) ◽  
pp. 14318-14324 ◽  
Author(s):  
Zehui Yang ◽  
Tsuyohiko Fujigaya ◽  
Naotoshi Nakashima
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Phosphoric Acid ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Fuel Cells ◽  
Fuel Cell Performance ◽  
High Durability ◽  
And Performance

Low fuel cell performance and durability are still the two main obstacles to the commercialization of high-temperature polymer electrolyte fuel cells.

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