Graphene and Energy

Dr Etienne Quesnel, a senior expert in Material Sciences at CEA-Grenoble, France, is the leader of this Work Package. Here, he will give some further insights to the ‘perfect match’ between graphene and energy.

On itself the production and storage of energy is today a big societal issue. In particular because of the increasing worldwide demand in energy, but also because of the scarcity of some mineral resources and the need of sustainable solutions taking into account the climate global warming.

Today, various technical solutions already exist in photovoltaics or in batteries, but they are not enough performing and cost effective for a massive use and sometimes not adapted to the needs.

Graphene could help making these solutions more competitive, since graphene offers properties that could either improve existing technologies or trigger the development of more promising energy concepts.

Can you give any examples?

“Yes, let’s take solar cells. The present market is dominated, for years, by the first generation of solar panel based on crystalline silicon. With an energy conversion efficiency of 15-20%, the cost of energy produced by these panels must be lower than 1€ per watt to be competitive. Decreasing this price requires either increasing the conversion efficiency, which Physics not always enables, or developing alternative low cost technologies based on thin films or roll to roll production solutions.

Graphene by its natural flexibility and by the possibility of processing it in solution or inks by wet chemistry is well suited to this kind of production methods.

It can be used for instance to produce the transparent conductive electrodes needed in the solar cell devices and thus replace the Indium widely used in conventional electrodes, this indium metal being known for its critical scarcity

It can also be used to develop novel materials better absorbing the sun light, graphene-quantum dots composite materials for instance, to design much more efficient solar devices.

For the other topics like batteries, super-capacitors, fuels cells or hydrogen storage tanks, the interest of graphene is similar with both aspects, improvement of existing technologies and development of novel breakthrough solutions.”

What are the biggest challenges regarding introduction of graphene into the energy field?

“The very first one is to have on our disposal good quality graphene material in sufficient quantity. For our development we have the chance to work within a large consortium with graphene producers and it is clearly a plus. But more generally, the availability of large quantity of graphene could be a challenge in the future, especially if the applications require very high quality material in large quantities.

The second challenge is to demonstrate that graphene can be effectively integrated into energy devices while preserving its outstanding properties, such as electronic conductivity, transparency,etc. This is one of the main objectives of our work package where we carefully implement various technologies of graphene integration for applications as different as solar cells, battery, supercapacitors, fuel cells and hydrogen storage.

The third challenge is to demonstrate that graphene can indeed significantly improve the performances of energy devices without requiring too sophisticated and costly technological solutions.

Last but not least, it is to invent new graphene-based devices showing better performances but also bringing new functionalities. Innovation is of course at the heart of our activities to, at the end, boost the European industry.”

In October, there will be a Graphene Connect about Energy Applications. Why is such industrial workshop important?

“I am convinced that graphene and more generally 2D materials will be used in the field of Energy devices at the 2020 horizon. The question is to know precisely for which kind of market. Shall we stay at the level of various niche markets? Or shall we manage to identify THE application that will push towards massive production of graphene material?

This is precisely the interest and objective of the industrial workshop we are organizing in Dresden. It is very important to share information with the European industry, for the researchers to have a feedback from the application side, for the industrials to be informed about the potentialities of graphene for their products.”

Finally, what are the “latest news” regarding the work within Work Package Energy?

“We have started working only nine months ago and I must say that the collaboration between the 14 partners is excellent. We already get some interesting proof of concepts, with real operating devices put on the table.

For instance, they are nice results on organic solar cells integrating graphene-based layers in different parts of the device stack and showing very promising performances. Moreover the technology to process the graphene is very smart, easy to use and perfectly adapted to roll to roll technology.

As another example, I can also mention the achievement of a flexible battery prototype using a single monolayer of graphene. We demonstrate that even with such a low quantity of graphene the battery can power a LED lighting device.”

FACTS: Dr Etienne Quesnel, is senior expert at CEA-Grenoble (France) in Material Sciences with more than 90 articles published in peer reviewed journals and international conference proceedings and 16 international patents. He has been working for more than 20 years on thin film technologies mainly for optics, microelectronics and opto-electronic applications. Currently, inside the CEA-Liten institute (http://www-liten.cea.fr/ ) his major research focus is on nanotechnologies for renewable energy applications. As an example of past activities in that field, he developed a magnetron-based nanoagregate technology to synthesize metallic NPs for plasmonics in solar cells, and catalysts in fuel cells as well as Ge nanocrystals (QDs) for their integration into 3rd generation solar cell devices. He has been involved in numerous National and European cooperation projects, as technical contributor and / or coordinator like in the recent FP7 SOLAMON and AGATHA projects. Since end of 2013, within the GRAPHENE FLAGSHIP, he is the coordinator of the workpackage on energy applications.

Banner image: Peter Widing, Chalmers University of Technology, 2014.