Alternate Hydrogen Pump Method Enables Start-Up from −30°C for Graphite-Bipolar-Plate Proton Exchange Membrane Fuel Cells

2019 ◽  
Vol 166 (14) ◽  
pp. F1112-F1116 ◽  
Author(s):  
Junning Wen ◽  
Dechun Si ◽  
Shangshang Wang ◽  
Han Ding ◽  
Chaoming Li ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Bipolar Plate ◽  
Proton Exchange ◽  
Start Up ◽  
Hydrogen Pump ◽  
Exchange Membrane

From –20 to 200 °C: Fuel Cells with Broad Operational Flexibility Enabled by Intrinsically Ultramicroporous Membranes

2021 ◽  
Author(s):  
Hongying Tang ◽  
Kang Geng ◽  
Lei Wu ◽  
Junjie Liu ◽  
Zhiquan Chen ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Operational Flexibility ◽  
Full Spectrum ◽  
Innovative Design ◽  
Temperature Range ◽  
Temperature Conditions ◽  
Start Up ◽  
Exchange Membrane

Abstract Conventional proton exchange membrane fuel cells (PEMFCs) operate at a narrow temperature range, either under low temperature conditions (80‒90°C) using fully-humidified perfluorosulfonic acid (Nafion®) membranes or under non-humidified high temperature conditions (140‒180°C) using phosphoric acid (PA)-doped membranes to avoid water condensation-induced PA leaching. To allow wide operational flexibility over the full spectrum of temperature and humidity ranges, we present an innovative design strategy by using PA-doped intrinsically ultramicroporous membranes constructed from rigid and contorted high free volume polymers. The membranes with an average ultramicropore radius of 3.3 Å showed a significant siphoning effect as confirmed by the delocalization of PA in 31P NMR, thus allowing high retention of PA even under highly humidified conditions and presenting more than three orders of magnitude higher proton conductivity retention than conventional dense PA-doped polybenzimidazole membranes (PBI/PA). The resulting PEMFCs display impressive performance over a much broader temperature range from − 20 to 200°C and can accomplish over 100 start-up/shut-down cycles even at − 20°C. The broad operational flexibility rendered from the high PA-retention can ultimately simplify heat and water management and thereby reduce PEMFC costs.

Development of a 600 W Proton Exchange Membrane Fuel Cell Power System for the Hazardous Mission Robot

2010 ◽  
Vol 7 (3) ◽  
Author(s):  
Sang-Yeop Lee ◽  
In-Gyu Min ◽  
Hyoung-Juhn Kim ◽  
Suk Woo Nam ◽  
Jaeyoung Lee ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Power System ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Hybrid Control ◽  
Operation Time ◽  
Proton Exchange ◽  
Power Sources ◽  
Start Up ◽  
Exchange Membrane

Due to the advantage of fuel cells over secondary batteries such as long operation time, many efforts were executed in order to use fuel cells as main power sources of small electronic devices such as laptop computers and mobile phones. For the same reason, fuel cells are promising power sources for the hazardous mission robots. Fuel cells are able to increase their radius action through extension of operation time. Despite this advantage, there still exist technical barriers such as increasing power density, efficient hydrogen storage, and fast startup of the power system. First, in order to increase power density, the united stack including proton exchange membrane fuel cells (PEMFC) and membrane humidifying cells were developed. Also, the hydrogen generating system using NaBH4 solution was employed to store hydrogen effectively. In addition, to shorten start-up time, hybrid control of PEMFC and Li-ion battery was adopted. The approaches mentioned above were evaluated. The developed PEMFC/humidifier stack showed high performance. As compared with full humidification condition by external humidifiers, the performance decrease was only 1% even though hydrogen was not humidified and air was partially humidified. Besides, by integrating the PEMFC and the humidifier into a single stack, considerable space for tubing between them was saved. Also, the hydrogen generator operated well with the PEMFC system and allowed for effective fuel storing and refueling. In addition, due to the efficient hybrid control of PEMFC and battery, start-up time was significantly shortened and capacity of PEMFC was reduced, resulting in compactness of the power system. In conclusion, a 600 W PEMFC power system was developed and successfully operated with the robot. Through development and evaluation of the PEMFC power system, the possibility of PEMFC as a novel power source for the hazardous mission robot was verified.

Constructal flow distributor as a bipolar plate for proton exchange membrane fuel cells

2011 ◽  
Vol 36 (20) ◽  
pp. 12965-12976 ◽  
Author(s):  
Bladimir Ramos-Alvarado ◽  
Abel Hernandez-Guerrero ◽  
Francisco Elizalde-Blancas ◽  
Michael W. Ellis
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Bipolar Plate ◽  
Proton Exchange ◽  
Exchange Membrane ◽  
Flow Distributor
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