Degradation Mechanism of Oxygen Electrode Under Fuel-Cell and Electrolysis Mode Operations

2019 ◽  
Vol 91 (1) ◽  
pp. 681-685
Author(s):  
Jong-Ho Lee ◽  
Ho Il Ji ◽  
Sanghyeok Lee ◽  
Ji-Su Kim ◽  
Sung Min Choi ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Degradation Mechanism ◽  
Oxygen Electrode ◽  
Electrolysis Mode

scholarly journals Degradation of MCFC Materials in a 81 cm2 Single Cell Operated Under Alternated Fuel Cell/Electrolysis Mode

2021 ◽  
Vol 9 ◽  
Author(s):  
Stefano Frangini ◽  
Massimilano Della Pietra ◽  
Livia Della Seta ◽  
Claudia Paoletti ◽  
Juan Pedro Pérez-Trujillo
Keyword(s):  
Fuel Cell ◽  
Single Cell ◽  
Current Collector ◽  
Oxygen Electrode ◽  
Internal Resistance ◽  
Electrode Polarization ◽  
Post Mortem ◽  
Molten Carbonate ◽  
Operation Modes ◽  
Electrolysis Mode

The possibility of producing hydrogen from molten carbonate steam electrolysis using the well-established Molten Carbonate Fuel Cell (MCFC) technology was explored in this work. For this purpose, a 81 cm2 MCFC single cell assembled with conventional cell materials was operated under alternated fuel cell/electrolysis conditions at 650°C in a binary eutectic Li2CO3-K2CO3 electrolyte for about 400 h after an initial period of 650 h in which the cell worked only in the usual MCFC mode. A rapid cell performance loss in terms of cell internal resistance and electrode polarization was observed as soon as the cell started to work in the alternated fuel cell/electrolysis mode. After test completion, a post-mortem analysis was conducted to correlate the electrochemical response with cell materials degradation. Cell materials of the reverse cell were compared against a reference single cell that was assembled with the same materials and operated only in the fuel cell mode under comparable experimental conditions. Post-mortem analysis allowed to identify several serious stability issues of conventional MCFC materials when used in alternated operation modes. Thus, although the electrolyte matrix appeared almost unaffected, a significant amount of dissolved nickel was found in the matrix indicating that electrolysis operations promote an increasing chemical instability of the NiO oxygen electrode. A serious reduction of electrode porosity was also observed in both NiO oxygen and Ni metal fuel electrodes, which could explain the higher polarization resistance of the reversible cell in comparison to the reference MCFC cell. Furthermore, the oxygen current collector made with conventional 316L stainless steel was found to be seriously corroded under the alternated operation modes. Thus, the observed rapid increase in internal resistance in the reverse cell could be caused, at least in part, by an increased contact resistance between the oxygen electrode and the corroding current collector structure. Possible solutions for improving stability of electrodes and of the oxygen current collector in reverse MCFC cells were proposed and discussed in the final part of the work.

Role of dissolved oxygen on the degradation mechanism of Reactive Green 19 and electricity generation in photocatalytic fuel cell

Chemosphere ◽  
2018 ◽  
Vol 194 ◽  
pp. 675-681 ◽  
Author(s):  
Sin-Li Lee ◽  
Li-Ngee Ho ◽  
Soon-An Ong ◽  
Yee-Shian Wong ◽  
Chun-Hong Voon ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Dissolved Oxygen ◽  
Electricity Generation ◽  
Degradation Mechanism ◽  
Photocatalytic Fuel Cell ◽  
Reactive Green 19

Design and Testing of a Unitized Regenerative Fuel Cell

2009 ◽  
Vol 6 (3) ◽  
Author(s):  
Jeremy Fall ◽  
Drew Humphreys ◽  
S. M. Guo
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Platinum Catalyst ◽  
Oxygen Electrode ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Hydrogen Electrode ◽  
Iridium Catalysts ◽  
Regenerative Fuel Cell

A unitized regenerative fuel cell (URFC) is designed and tested for energy conversion and storage under the support of a NASA funded student design project. The URFC is of the proton exchange membrane type with an active cell area of 25cm2. In the URFC design, liquid water is stored internally to the fuel cell within graphite bipolar plates while hydrogen and oxygen gases, electrolyzed from water, are stored in containers external to the fuel cell. A spraying technique is used to produce a functional membrane electrode assembly. Catalyst ink is prepared using E-TEK Inc. platinum and iridium catalysts loaded on Vulcan XC-72. Platinum catalyst is used for the hydrogen electrode. 50wt% platinum∕50wt% iridium catalyst is used for the oxygen electrode. The metal weight on carbon is 30% for both the platinum and iridium catalysts. Water management within the fuel cell is handled by treatment of the gas diffusion layer with a Teflon emulsion to create the proper balance of hydrophobic and hydrophilic pores. The single cell unit is tested in either fuel cell mode or electrolysis mode for different catalyst loadings. Polarization curves for the URFC are generated to evaluate system performance.

Development of a Method for Clarifying the Perfluorosulfonated Membrane Degradation Mechanism in a Fuel Cell Environment

2008 ◽  
Vol 155 (1) ◽  
pp. A29 ◽  
Author(s):  
Satoru Hommura ◽  
Kengo Kawahara ◽  
Tetsuji Shimohira ◽  
Yasutake Teraoka
Keyword(s):  
Fuel Cell ◽  
Degradation Mechanism ◽  
Membrane Degradation
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