Global Sources
EE Times-India
Stay in touch with EE Times India
 
EE Times-India > Power/Alternative Energy
 
 
Power/Alternative Energy  

Graphene holds key to improve fuel cell performance

Posted: 02 Dec 2014     Print Version  Bookmark and Share

Keywords:University of Manchester  fuel cell  graphene  proton  proton-conducting membrane 

A team of researchers from the University of Manchester researchers has discovered that graphene, which is impervious to all gases and liquids, has the capability to easily allow protons to pass through it. According to them, the findings could transform fuel cells because they need a barrier that only allow protons to pass through.

Additionally, graphene membranes could be used to sieve hydrogen gas out of the atmosphere, where it is present in minute quantities, creating the possibility of electric generators powered by air.

One-atom thick material graphene, first isolated and explored in 2004 by a team at The University of Manchester, is renowned for its barrier properties. A research group led by sir Andre Geim tested whether protons are also repelled by graphene. The researchers expected that protons would be blocked, as existing theory predicted as little proton permeation as for hydrogen.

Graphene

University of Manchester researchers discovered that graphene, which is impervious to all gases and liquids, has the capability to easily allow protons to pass through it.

Despite the pessimistic prognosis, the researchers found that protons pass through the ultra-thin crystals surprisingly easily, especially at elevated temperatures and if the films were covered with catalytic nanoparticles such as platinum.

The discovery makes monolayers of graphene, and its sister material boron nitride, attractive for possible uses as proton-conducting membranes, which are at the heart of modern fuel cell technology. Fuel cells use oxygen and hydrogen as a fuel and convert the input chemical energy directly into electricity. Without membranes that allow an exclusive flow of protons but prevent other species to pass through, this technology would not exist.

Despite being well-established, fuel-cell technology requires further improvements to make it more widely used. One of the major problems is a fuel crossover through the existing proton membranes, which reduces their efficiency and durability.

The research suggests that the use of graphene or monolayer boron nitride can allow the existing membranes to become thinner and more efficient, with less fuel crossover and poisoning that boosts competitiveness of fuel cells.

The Manchester group also showed that their membranes can be used to extract hydrogen from a humid atmosphere. They hypothesise that such harvesting can be combined together with fuel cells to create a mobile electric generator that is fuelled simply by hydrogen present in air.

Marcelo Lozada-Hidalgo, a PhD student and corresponding author of the paper, said: When you know how it should work, it is a very simple setup. You put a hydrogen-containing gas on one side, apply small electric current and collect pure hydrogen on the other side. This hydrogen can then be burned in a fuel cell.

We worked with small membranes, and the achieved flow of hydrogen is of course tiny so far. But this is the initial stage of discovery, and the paper is to make experts aware of the existing prospects. To build up and test hydrogen harvesters will require much further effort.

Sheng Hu, a postdoctoral researcher and the first author in this work, added: It looks extremely simple and equally promising. Because graphene can be produced these days in square metre sheets, we hope that it will find its way to commercial fuel cells sooner rather than later.

The work is an international collaboration involving groups from China and the Netherlands who supported theoretical aspects of this research. Marcelo Lozada-Hidalgo is funded by a PhD studentship programme between the National Council of Science and Technology of Mexico and The University of Manchester.

- Paul Buckley
  EE Times Europe





Comment on "Graphene holds key to improve fuel c..."
Comments:  
*  You can enter [0] more charecters.
*Verify code:
 
 
Webinars

Seminars

Visit Asia Webinars to learn about the latest in technology and get practical design tips.

 

Go to top             Connect on Facebook      Follow us on Twitter      Follow us on Orkut

 
Back to Top