By Vincenzo Palermo, vice-director of European Commission research project The Graphene Flagship.
Does science have a responsibility to be sustainable? The Graphene Flagship thinks so, and as such, is working to bring graphene out of labs and into society.
In simple terms, graphene is a two-dimensional atomic crystal made up of carbon atoms arranged in a hexagonal lattice.
Due to its unique combination of superior properties, graphene is a credible starting point for new disruptive technologies across a wide range of fields.
Pursuing sustainability through scientific excellence has been at the heart of the Graphene Flagship since its inception. More recently, we have decided to make this effort more visible by clearly linking our efforts to the United Nations’ 17 sustainable development goals (SDGs).
This has helped us to share our vision externally and challenged us to find new, disruptive ways in which our technology can help Europe become more sustainable.
The European Union has set ambitious targets for sustainability and the environment. At the heart of the European Green Deal is the pledge to be climate-neutral by 2050.
Two spearhead projects that promise significant impact on environmental challenges focus on technologies for energy storage and energy generation.
Energy storage for electric vehicles
SDG 13, climate action, looks at ways that countries, organisations and individuals can mitigate the effects of climate change. In line with this goal, the EU has pledged to see at least 40% cuts in greenhouse gas emissions, from 1990 levels, and at least a 32.5% improvement in energy efficiency by 2030.
Transport accounts for almost a quarter of the EU’s greenhouse gas emissions, and the European Green Deal seeks a 90% reduction in this by 2050. One of the ways to achieve this is through electrical vehicles — by 2025, around 13 million zero- and low-emission vehicles are expected on European roads.
However, while they offer a reduction in emissions, electric vehicles do have drawbacks. Charging, range and cost are just some of the concerns regarding electric vehicle batteries.
Therefore, improvements in energy storage technology will be necessary to achieve the EU’s goals for transport emissions and energy efficiency.
The Graphene Enabled High-Energy Batteries for Automotive Applications (GreenBAT) project aims to improve battery technology for electric vehicles, helping the EU achieve its sustainability goals.
Alongside other industrial partners involved in GreenBAT, VARTA Microbattery, BeDimensional and VARTA Micro Innovation are developing battery technology based on a patented graphene fabrication and silicon-graphene compounding process.
Currently, lithium-ion battery technology is unrivalled, as it is the most mature and flexible system. The introduction of nickel-rich cathodes and silicon-composites will represent the next generation of lithium-ion batteries.
Graphene, or more specifically few-layered graphene, improves cyclability, leading to an overall energy increase of 25% when used in silicon-dominant anodes.
Another roadblock to sustainability is that the manufacturing process for EVs generates more emissions than producing internal combustion engines, mainly due to the production of batteries and battery materials.
So, Graphene Flagship partners are also researching improving lithium ion battery production and creating a circular economy for batteries.
While EVs and more efficient energy storage present a way to reduce greenhouse gas emissions for the transport sector, this is only a real saving if the energy used to power them is generated sustainably.
Solar energy generation
By 2030, the EU aims to see at least a 32% share for renewable energy in Europe’s energy mix. Efficient solar power generation will be necessary to meet this target.
However, mainstream silicon solar technology is reaching the limit of its economic and practical photovoltaic efficiency. Perovskite solar cells (PSCs) are widely predicted to offer a solution, offering much better performance than their silicon counterparts. The downside is that PSCs are infamously unstable, which is where graphene comes in.
Graphene Flagship spearhead project GRAPES aims to make cost-effective, stable graphene-enabled perovskite panels. It is aligned with SDG 7, clean and affordable energy.
One Graphene Flagship partner involved in GRAPES is ENEL Green Power. This leading green energy company holds the world record power conversion efficiency (PCE) for a silicon heterojunction cell, 24.63%, but believes graphene will help them beat that.
By using graphene and related materials (GRMs) as interlayers in tandem cells that combine PSCs and silicon cells, ENEL Green Power and Graphene Flagship partners have reached record stability and efficiency, demonstrating a PCE increase of nine per cent for GRM-based perovskite-silicon tandem cells, as opposed to tandem cells without GRMs.
As well as taking advantage of the transparency and stability of graphene in the interlayers of the solar cell, a highly conductive graphene-based paste will be used in the back contact and metal front grid, replacing expensive and finite metals such as silver.
GRAPES will play an essential role in improving Europe’s uptake of solar energy projects and meeting its environmental targets, particularly by improving the stability and efficiency of solar cell technology when deployed on a large scale.
Scientific knowledge is able to improve lives and is a key tool to fighting climate change and ensuring a future for generations to come. The Graphene Flagship hopes to lead the way by focusing on energy efficiency, the replacement of rare materials by common ones, and ensuring its research is environmentally compatible. Through aligning our work with the sustainable development goals, we have made this focus even more visible, and will continue to work towards securing a greener future for Europe.
Find out more about the Graphene Flagship’s work on sustainability.