scholarly journals Designing Carbon/Oxygen Ratios of Graphene Oxide Membranes for Proton Exchange Membrane Fuel Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Minwoo Ahn ◽  
Renlong Liu ◽  
Changgu Lee ◽  
Wonyoung Lee
Keyword(s):  
Graphene Oxide ◽  
Fuel Cells ◽  
Power Density ◽  
Proton Conductivity ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Maximum Power ◽  
Maximum Power Density ◽  
Exchange Membrane ◽  
Interfacial Reactivity

Graphene oxide (GO), which is the oxidized form of graphene, has holes and functional groups on the surface and thus has high potential to be used as an electrochemical transport channel material. In this study, differently modified GO membranes are applied as electrolytes of proton exchange membrane fuel cells (PEMFCs) with controlled carbon/oxygen ratios. The critical and desired properties of the electrolyte, such as electron conductivity, proton conductivity, interfacial reactivity, and cell performance are evaluated in identical platinum-sputtered model electrodes. Among them, with the help of an increased concentration of oxygen-containing groups, a GO membrane with a low carbon/oxygen ratio shows a 2.9-fold improved maximum power density and advanced electrochemical properties compared with the pristine GO membrane. The characterization of GO suggests that the redox state of the membrane is an important factor for controlling the proton conductivity, interfacial reactivity, and maximum power density of PEMFCs.

scholarly journals Ecological Performance Optimization of a High Temperature Proton Exchange Membrane Fuel Cell

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1332
Author(s):  
Dongxu Li ◽  
Siwei Li ◽  
Zheshu Ma ◽  
Bing Xu ◽  
Zhanghao Lu ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
High Temperature ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Operating Temperature ◽  
Proton Exchange ◽  
Maximum Power ◽  
Operating Pressure ◽  
Maximum Power Density ◽  
Exchange Membrane

According to finite-time thermodynamics, an irreversible high temperature proton exchange membrane fuel cell (HT-PEMFC) model is established, and the mathematical expressions of the output power, energy efficiency, exergy efficiency and ecological coefficient of performance (ECOP) of HT-PEMFC are deduced. The ECOP is a step forward in optimizing the relationship between power and power dissipation, which is more in line with the principle of ecology. Based on the established HT-PEMFC model, the maximum power density is obtained under different parameters that include operating temperature, operating pressure, phosphoric acid doping level and relative humidity. At the same time, the energy efficiency, exergy efficiency and ECOP corresponding to the maximum power density are acquired so as to determine the optimal value of each index under the maximum power density. The results show that the higher the operating temperature and the doping level, the better the performance of HT-PEMFC is. However, the increase of operating pressure and relative humidity has little effect on HT-PEMFC performance.

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.

Optimization of the Operating Parameters of a Proton Exchange Membrane Fuel Cell for Maximum Power Density

2005 ◽  
Vol 2 (2) ◽  
pp. 121-135 ◽  
Author(s):  
A. Mawardi ◽  
F. Yang ◽  
R. Pitchumani
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Design Parameters ◽  
Membrane Thickness ◽  
Exchange Membrane

The performance of fuel cells can be significantly improved by using optimum operating conditions that maximize the power density subject to constraints. Despite its significance, relatively scant work is reported in the open literature on the model-assisted optimization of fuel cells. In this paper, a methodology for model-based optimization is presented by considering a one-dimensional nonisothermal description of a fuel cell operating on reformate feed. The numerical model is coupled with a continuous search simulated annealing optimization scheme to determine the optimum solutions for selected process constraints. Optimization results are presented over a range of fuel cell design parameters to assess the effects of membrane thickness, electrode thickness, constraint values, and CO concentration on the optimum operating conditions.

Controlling fuel crossover and hydration in ultra-thin proton exchange membrane-based fuel cells using Pt-nanosheet catalysts

2014 ◽  
Vol 2 (39) ◽  
pp. 16416-16423 ◽  
Author(s):  
Rujie Wang ◽  
Wenjing Zhang ◽  
Gaohong He ◽  
Ping Gao
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Exchange Membrane

A fuel cell with a 9 μm thick proton exchange membrane bearing Pt-nanosheet catalysts delivered 200% more power density as compared with a fuel cell with commercial Nafion® 211 membrane.

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