“It is important to break the dominance of lithium-ion technology”
“15 + 10“ years of concentrated power for battery research: Fifteen years ago, the MEET Battery Research Center at the University of Münster was launched. Five years later, the Helmholtz Institute Münster (HI MS) “Ionics in Energy Storage“ moved into the immediate neighbourhood. Both institutions are celebrating their double anniversary on 7 July. On this occasion, Prof Martin Winter provides insights into current battery research, trends and market strategies in an interview with Christina Hoppenbrock. Martin Winter is closely associated with both organisations: He is the founder and scientific director of MEET and founding director of HI MS.
What have been the outstanding developments in battery technology over the past 15 years?
The lithium-ion battery has dominated the market for almost 35 years. In recent years, it has been continuously improved and has become more powerful, more durable and even safer. Such further developments are only possible through long-term, targeted research. At the same time, we are focussing on alternative cell chemistries with a higher energy density. One example of this is the lithium metal battery. These energy storage systems are particularly attractive for electromobility, as they have the potential to realise a greater range than the lithium-ion battery. This battery chemistry can be designed with liquid and solid electrolytes, which we are researching intensively in Münster, particularly at the Helmholtz Institute. However, we are still on a learning curve. There is no automatism that ensures that the lithium metal battery will be an energy storage solution of the future.
So you still think that lithium-ion technology has a future?
Even if many people don't want to believe it: The lithium-ion battery will become even better because we are continuing to research it intensively, both in the fundamentals and in the applications. Nevertheless, it is important to break the dominance of lithium-ion technology. With more and more applications, the market will become more differentiated.
Are there other battery technologies that are currently on the rise?
We believe it is very likely that the sodium-ion battery will initially gain a further place in the market. It is a so-called drop-in technology. This means that existing production facilities for lithium-ion batteries can be converted to the production of sodium-ion batteries relatively easily. The topic also plays an important role in Münster: together with 20 other project partners, the MEET Battery Research Center and the Helmholtz Institute Münster are currently part of Germany's largest consortium for sodium-ion batteries. The aim of the project is to establish a comprehensive industrial ecosystem for the production of sodium-ion batteries.
And what about environmental protection?
The topic of sustainability has strongly characterised battery research in recent years, particularly recycling and the circular economy. One approach is the concept of 'design for recycling'. It aims to standardise and design the structure of battery modules or cells in such a way that the battery or cells can be deconstructed into their individual components as automatically as possible. The approach also includes material design. For example, water-based 'green' binder systems for electrode materials are to be developed in order to reduce or eliminate expensive, potentially toxic solvents or the fluorinated binders currently used during recycling. Another approach that we have researched intensively at MEET and are developing further is direct recycling. This involves reactivating active materials, mainly from the cathode, after use so that they can be used directly in new cells. The Helmholtz Institute in Münster is also working intensively on the recycling of solid-state batteries.
Despite all these advances and further developments in Münster and elsewhere, haven't China and other Asian countries long since left Germany behind in the field of battery technology?
It's not about winning against Asia, but about securing our own share of a rapidly growing market. Global competitiveness and independence from high-tech locations will depend to a large extent on the ability to produce and further develop batteries ourselves. This is another reason why the Federal Ministry of Research, Technology and Space alone has invested more than one billion euros in the development of German battery research over the past 15 years. After many years of development, we have now reached the phase in which we are transferring our research results to industry.
However, the current economic situation is not very encouraging ...
Nevertheless, German industry is currently expanding production in the field of electromobility. We now need to continue along this path consistently to avoid being left behind. In order to counter the dominance of Asian players in battery technology and the associated supply chains, Germany and Europe must constantly build up the expertise and technologies for large-volume battery cell production for all applications, also as insurance against geopolitical dependencies.
The USA has so far been a reliable partner in the field of research, but this certainty is crumbling. What impact are the current developments in the USA, for example budget reductions, having on research here?
There will be consequences, but these cannot yet be definitively assessed. We can still build on our good relationships and long-term collaborations, for example with the Pritzker School of Molecular Engineering at the University of Chicago, Berkeley National Laboratory, Argonne National Laboratory and Stanford University. In 2019, we initiated a German-American collaboration in battery research that has been very successful for many years.