Graphene breakthrough could trigger electric car revolution: Proton discovery paves way to super-efficient batteries
- Graphene is the world's thinnest and strongest material that is impermeable to atoms and molecules
- Researchers from the University of Manchester were surprised to find that positively charged hydrogen atoms - protons - can pass through it
- Discovery could boost efficiency of fuel cells for cars generating electricity from hydrogen, by using a graphene-based membrane
Scientists
have discovered a surprising new property of graphene – the world’s
thinnest and strongest material – that could accelerate the development
of electric cars and other green technologies.
Researchers
have found that the newly discovered type of carbon graphite, which is
found in pencil lead, allows positively charged hydrogen atoms or
protons to pass through it.
Their discovery could increase the efficiency of fuel cells for cars, because the cells generate electricity from hydrogen.
Researchers have found that the newly
discovered type of carbon graphite called graphene, which is found in
pencil lead, allows positively charged hydrogen atoms or protons to pass
through it. An atomic-scale honeycomb lattice made of carbon atoms is
pictured
The
researchers, led by Nobel Prize winner Sir Andre Geim of Manchester
University, who discovered graphene, said their finding raises the
possibility that, in future, graphene membranes could be used to ‘sieve’
hydrogen gas from the atmosphere to generate electricity.
This
is because the one-atom thick material acts like a filter to allow
protons to pass through it, while blocking the passage of other atoms.
The team demonstrated this when they combined the substance with a single-atom material called boron nitride.
Scientists were able collect protons on one side of a membrane, with other blocked atoms accumulated in a chamber.
Using
such a membrane, fuel cells could extract hydrogen from the air and
burn it in order to power electric cars, which wouldn’t spew out
environmentally harmful emissions.
The discovery could increase the
efficiency of fuel cells in cars, because the cells generate electricity
from hydrogen. While hydrogen is being used to fuel concept cars
(pictured) the technology has a distance to go before it is widely
commercialised
‘We
are very excited about this result because it opens a whole new area of
promising applications for graphene in clean energy harvesting and
hydrogen-based technologies,’ said Marcelo Lozada-Hidalgo, co-researcher
on the study.
At just one atom thick, graphene is the thinnest material on Earth and is also 200 times stronger than steel.
It was first isolated in 2004 by Sir Andre and his fellow researchers, who received a Nobel Prize in 2010 for their work.
The
material is impermeable to all gases and liquids, giving it the
potential for a range of uses such as corrosion-proof coatings,
packaging and even super-thin condoms.
The
new discovery, published in Nature, came about because the team wanted
to investigate whether protons (hydrogen atoms stripped of their
electrons) were repelled by the material, which is impermeable to the
smallest atom, hydrogen.
They
were surprised to find that the protons could pass through the
ultra-strong material fairly easily, especially at raised temperatures
and if the graphene films were covered with nanoparticles such as
platinum, which acted as a catalyst.
Sir
Andre and Dr Lozada-Hidalgo hope that graphene could one day be used in
proton-conducting membranes, which are a crucial component of fuel cell
technology.
Fuel cells, used in some modern cars, use oxygen and hydrogen as fuel and convert the input chemical energy into electricity.
But
a major problem is that the fuels leak across the existing proton
membranes to reduce the cells' efficiency. This problem could be
overcome by using graphene.
At just one atom thick, graphene is
the thinnest material on Earth and is also 200 times stronger than
steel. It was first isolated in 2004 by Sir Andre Geim (left) and Dr
Konstantin Novoselov (right) who were awarded the Nobel Prize for
Physics in 2010
The
team found that graphene membranes could be used to extract hydrogen
from the atmosphere, suggesting the possibility of combining them with
fuel cells to make mobile electric generators powered just by tiny
amounts of hydrogen in the air.
‘Essentially, you pump your fuel from the atmosphere and get electricity out of it,’ Sir Andre said.
‘Our (study) provides proof that this kind of device is possible.’
Dr
Sheng Hu, a postdoctoral researcher and the first author in this work,
added: ‘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’.
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