How can nanocarbons improve different methods of storing (renewable) energy?

Ever since the Network NanoCarbon has been founded in 2013, one of the most discussed topics in our meetings was the identification of different fields of application that would allow to utilise the outstanding properties of nanocarbon materials. While in earlier years the search for a „killer application“ for CNTs was in the focus, it became more and more clear that the development of multiple, specialised niche products was more promising. Even though the research on nanocarbon materials, especially on graphene, certainly is not done yet and keeps bringing exciting new insights, the industrialisation and commercialisation has come a long way. Among the different fields of application, energy storage has always been very promising, for example by implementing CNTs as conductive additives for electrodes in Lithium-ion batteries.

With topics like storing renewable energy or electromobility gaining more impact on building a sustainable future, the discussion has also caused a stir in the general public and politics have decided to support research efforts in this field. For example, the European Battery Alliance will be given a massive financial boost by the European Investment Bank (EIB): the bank expects to increase its backing of battery-related projects to more than 1 billion Euro of financing in 2020. This matches the level of support the EIB has offered over the last decade. A solid investment since driven by the growing demand for electric vehicles and renewable energy, the battery market will have an estimated annual value of up to 250 billion Euro by 2025.

More than enough reasons for the Network NanoCarbon to organise a focus workshop with the title „Nanocarbons for energy storage“ on October 14, 2020. About 40 participants from 12 different countries came together to meet the experts and join the discussion. Main topics of this event were hands-on solutions for the challenges in the field of energy storage and current research results.

The key technology energy storage is also in the focus of different competence centers. We are especially happy that experts from the Graphene Flagship have joined this workshop for a special session to share their knowledge. In the Graphene Flagship work package on energy storage, developers at the cell manufacturer VARTA Micro Innovation GmbH have an ongoing cooperation with researchers from the Istituto Italiano di Tecnologia (IIT). Together, they work on improving small electronic devices by the use of graphene. Prof. Pellegrini, leader of the work package gave an overview of two-dimensional materials for energy applications, while Dr Stangl presented a case-study by VARTA on graphene for batteries. Another important material of energy storage research that is drawing a lot of attention is hydrogen. We were joined by specialists from the Technische Hochschule Nürnberg with an announcement about the newly founded hydrogen campus (Dr Helbig) and current results on carbon-doped titanate nanotubes as novel materials in proton-exchange membrane fuel cells (Julia Hoppe).

Furthermore, specialists from small and medium-sized enterprises presented topics like Li-ion batteries and how to improve them using carbon nanotubes (Dr Boulanger, NAWATechnologies), the gain of graphene in ultracapacitors (Dr Pohlmann, Skeleton Technologies Group) as well as a new approach to implementing fuel cells in automotive applications (Dr Hickmann, Eisenhuth GmbH & Co. KG). This was an excellent opportunity for the participants to get insight into energy storage from a business oriented perspective. Especially during the discussion in the afternoon, participants used the chance to interact with these experts, get answers on detailed questions, gain insight into market developments and to make new connections with the other participants.

The discussion showed that two companies were especially in the focus of the participants‘ attention: Our network partner NAWATechnologies and Skeleton Technologies, leaders in ultracapacitor and supercapacitor energy storage.

Skeleton’s ultracapacitors, based on the patented material that they call “curved graphene”, are already used by automotive, transportation, grid, and industrial companies, helping them use less energy by hybridising or electrifying their businesses. The applications range from cars and trams over pitch control for wind turbines to industrial applications like warehouse robotics or port cranes. This makes Skeleton Technologies a widely recognised stakeholder at the forefront of the graphene industry, a role that has been regarded with several awards and mentions, among them being chosen as a Global Cleantech 100 company for the last 6 years in a row. Right now, they are making headlines for their partnership with the Karlsruhe Institute of Technology (KIT) on the development of a groundbreaking graphene battery with a 15-second charging time.

Also a key player in the supercap market, NAWATechnologies produces supercapacitors based on vertically aligned carbon nanotubes (VACNT). Their supercapacitors exhibit power densities between 10 and 100 times higher than existing technologies. NAWATechnologies has recently been recognised with the prestigious Solar Impulse Efficient Solution Label, an award that acknowledges the longstanding commitment both to clean technologies and social responsibility. During our workshop, Dr Boulanger presented a different groundbreaking technologie, an ultra-fast carbon electrode that has the potential to bring revolutionary improvements: in power density by a factor ten, energy storage by up to three, lifecycle by up to five and a reduction of the charging time down to minutes instead of hours. Also based on the patented VACNT design, the carbon electrode is the fastest in the world, combining highest ionic, electrical and thermal conductivity. The increased performance is achieved by a revolutionary nano-sized 3D design which means that batteries are no longer limited by powder-based systems and also has the potential for significant cost savings. With electrodes accounting for almost 25 per cent of the cost of a battery, this would be significant. After all, today’s global lithium-ion battery market is estimated at a worth of about 30 billion Euro.

However, even with all the outstanding developments in their respective field of research and the disruptive technologies at hand, all our experts agreed on the fact that not one single application will meet the world’s energy needs. Nanocarbon materials like CNTs and graphene bring significant advantages to supercapacitors and batteries alike, but the strength or weakness of each product depends highly on the intended field of application. Lithium-ion battery technology is well suited for energy storage, but is unable to cover peaks in energy consumption and does not even come close to ultracapacitors in reliability and safety. On the other hand, ultracapacitors cannot compete with batteries when it comes to energy density and still face the problem of higher self-discharge rates. Therefore, batteries and ultracapacitors are complementary technologies: batteries provide energy for the long term while ultracapacitors provide high power at fast reaction times. Together, as a hybrid technology, they will provide benefits no other energy storage technology can match and thereby driving the future of electrification.

Our online event was a great opportunity to highlight the role of nanocarbons in this ongoing development. We are looking forward to continue the discussion, for example during the next NanoCarbon Annual Conference on March 02-03, 2021.

For further information on this event, the Network NanoCarbon or the NanoCarbon Annual Conference please contact Dr Stefanie Bertsch, stefanie.bertsch(at), Phone: +49 931 31 89376. Released slides are available to the interested community against a small handling fee.