Efficient and Sustainable Resource and Cycle Strategies

Efficient and Sustainable Resource and Cycle Strategies

Author: Kira Welter, Anke WeidenkaffORCID iD


Professor Anke Weidenkaff is Director of the Fraunhofer Institution for Materials Recycling and Resource Strategies, IWKS in Alzenau, Germany, and she is organizing the first international conference on resource chemistry. Here she talks with Dr. Kira Welter, Senior Associate Editor of ChemPhysChem, for ChemistryViews about circular economy challenges, what fascinates her about her research, and the importance of social media.


With all the important discussions about climate change, plastic pollution, and so on, the term “circular economy” has become quite popular. Could you tell us briefly what that is?

There is a great number of definitions for the term “circular economy”. To keep it simple, for me, circular economy stands for a world without waste-deposition in the environment. A product has a certain life span: design, production, sales, application, and disposal. The aim of a circular economy is to make it a closed product cycle by re-use, recycling, refurbishment, or regeneration of all used materials.

Depositing waste has to be avoided by all means in the future. Waste not only pollutes our environment, soil, water, air. It also is a sign of bad management and it can severely endanger us. So, if we do not want to deposit, we have to use everything around us as raw material like nature does normally. And in a timely and energy-efficient way.


What are the main challenges associated with switching from the prevailing linear economy—take, make, dispose model—to a completely circular economy?

Each product stage brings a challenge for establishing a circular economy. To give an example: If we do not think of recycling when designing the product, this can pose a challenge for recovering all materials in high quality afterward.

Currently, we see that recycling quotas for certain products are already quite high, but many materials are downcycled in the recycling process and there is often a fraction that remains waste for disposal. So, it is not yet a closed-loop system. We have to design recycling technologies which are more cost-effective and energy-efficient. Materials have to be regenerated, repaired, healed, or innovatively modified. For example, a used electrode material of a battery might become a catalyst in its second life.


What do you think are the most urgent things scientists should do to address these challenges?

An important challenge scientists need to address is, of course, the improvement of existing recycling technologies and the development of new materials and products that make recycling much easier and more efficient. Here we have to apply our knowledge on structure-property relations of materials and recycling knowledge processes.

I think that we need to understand the irreversible processes leading to failure and the aging of materials to be able to reverse them. This could enhance the lifetime or—if innovation requires—disintegrate the material to precursors for other applications in terms of regeneration instead of recycling. One of the main questions that I am focusing on is: How can we design materials so we can also trigger and program these processes?


What made you get interested in these topics?

Society depends on high performance, progressively complex materials which contain high-tech and scarce elements. As materials scientists and chemists it is our responsibility to make sure that those are available for the desired functions.

My work was always focused on understanding the structure-property relation of materials to be able to design better materials for a purpose. The vast development in energy, environmental and information technologies requires more and more technical, sometimes critical metals. Thus, we become greatly dependent on the supply of new raw materials. What if we could recover them in a way to use them directly again for other applications? This would avoid separation, transportation, reduction, and purification processes of state-of-the-art recycling technologies. Our knowledge of materials has to be used to address our most pressing environmental problems and help to realize a sustainable and resource-efficient future without waste.


You have a background in materials science. How do you apply this knowledge to your current job?

In very simple terms: everywhere. Materials science plays an important role when thinking of sustainability and resources. For example, there would be no energy transition without a materials’ transition.

On the one hand, knowledge of materials is essential to design products with a desired lifetime from available resources. On the other hand, it is also essential for aspects such as the life-cycle analysis, digitalization, and criticality of products. Criticality can refer to toxic as well as scarce, or difficult to obtain elements. In many cases, a lot of energy, water, or other resources are needed to extract the required raw materials. If, for example, such a critical element can be substituted by another, less critical element, the entire sustainability of a product can be improved.


Since October 2018 you are the Director of the Fraunhofer IWKS. Which interesting projects are you and your colleagues currently working on?

It would probably take too long to name them all, but I am very proud that we are part of one of Fraunhofer’s lighthouse projects, “MaNiTu—materials for sustainable tandem solar cells with extremely high conversion efficiency”. The project focuses on perovskite solar cell technology, which has shown an increased efficiency from 3.8 % to 24.2 % within the last ten years.

The perovskite crystal structure is the most abundant crystal structure because it is extremely flexible and able to host even organic ions to form a hybrid material. It absorbs light particularly well, enables high electron mobility, and has desired self-healing properties. This is ideal for use in photovoltaics.

However, this material is not unproblematic because it contains lead. Since annual photovoltaic installations worldwide will rise to more than 1 TWp within the next five to ten years, critical materials in the manufacture of solar modules must be consistently avoided. This is one of the aspects I and my fellow researchers from Fraunhofer IWKS are working on within the project.


Your research group at the Fraunhofer Institute is quite new. What was it like to get things started? Which challenges did you face?

When you start something new, maybe one of the biggest challenges is to grow with limited resources. The IWKS started in 2011/2012 as a small project group. Step by step, competencies were built up and we established ourselves as experts in efficient and sustainable resource and cycle strategies. Today, we are about to move into two new buildings to grow even further and expand into new fields such as the digitalization of resources and a sustainable e-mobility.


Achieving a circular economy involves many aspects, so industry and politics will play very important roles too. Does the work at your institute include communication and/or collaborations with the industry and with policy makers?

As an applied research institution, we work very closely with the industry as well as policy makers. Apart from research projects with industry or public partners, we are also valued as neutral experts. This is also an important part of our mission—the transfer from research to industry and the public.


Sharing scientific results with a broader audience is very important to get more people involved with your work. Do you think using social media is a good way to communicate with other scientists and the public?

Yes. The use of social media clearly becomes more important as a novel, gainful, interactive way of science communication.

I am only beginning to use new media platforms to communicate with other scientists. Nevertheless, I believe it is very important to inform the public about our research work and we try to do this as openly as possible—starting from publishing Open Access, collaborating with journalists to posting about our research work on our own social media channels. We try to use a broad mix of communication channels to reach as many people as possible. In addition, I also think that we, as researchers, have to increase our efforts in the communication of scientific work and results for the public to profit from our know-how.


Could you tell us a bit more about your career before joining the Fraunhofer Institute?

Before joining the Fraunhofer IWKS and the materials science department of the Technical University of Darmstadt, I was Chair for Materials Chemistry and Director of the Institute for Materials Science at the University of Stuttgart. My doctorate in chemistry comes from the Swiss Federal Institute of Technology (ETH) in Zurich and the Venia Legendi for Solid State Chemistry and Materials Science from the University of Augsburg in Germany. For several years, I served as Section Head at the Swiss Federal Laboratories for Materials Science and Technology (Empa) in Dübendorf and as an Associate Professor at the University of Bern in Switzerland.

My publications and teaching were focused on materials development and soft chemistry synthetic methods for renewable energy converter technologies, including solar fuels, thermoelectric converters, and heterogeneous catalysis, as well as self-regenerative functional perovskite-type materials. In addition, I have promoted materials science as delegate of the EU-NMP program commission [here NMP stands for Nanotechnologies, Advanced Materials, and Advanced Manufacturing and Processing], member of the DFG (German Research Foundation) review board, president of the European Thermoelectric Society (ETS), member of the Executive Board of the German Chemical Society’s (GDCh) Division for Solid State Chemistry and Materials Research, and of the E-MRS (European Materials Research Society) Executive Committee.


What do you like most about your job?

The possibilities science has to offer to address important scientific challenges with creative solutions. The possibility to learn every day something new, to discover new materials enabling better technologies, and to teach, discuss, and share the knowledge with so many creative minds, students and scientists.


What motivates you when things get difficult?

Mastering difficulties always made me stronger and proud. A working life without challenges would be too boring for me. It feels good to get things done.

Also, I am convinced that we have to solve several challenging problems very soon, which requires hard work and several disruptive and exciting breakthrough results.


What do you enjoy doing in your spare time?

Family and my home in Switzerland. We live in the countryside, surrounded by beautiful mountains, cows, and other farm animals. They offer a lot of joy and recreational sports—and farming activities.


Finally, you are organizing the first International Conference on Resource Chemistry (ICRC), which will be held in March next year. Could you tell us a bit more about this conference?

The overall idea behind the conference is to discuss current developments and new ideas in resource chemistry with the leading figures in the field. In times of increasing pressure on industry and politics concerning environmental protection and climate change, material sciences and chemistry have to join forces to provide answers to some of the world‘s most challenging technological tasks. Under the aspect to secure and provide indispensable materials in a limited environment, our conference will specifically focus on applied resource chemistry and new recycling technologies. It will cover a wide range of research areas, from the substitution of critical elements to the development of sustainable materials and the establishment of efficient material life cycles.

I also would like to take the opportunity to invite and encourage scientists and experts from various fields, such as resources and green chemistry, biology, environmental science and technology, as well as material sciences, to join our conference—as a visitor, with a talk, or with a poster contribution.


Thank you for the interview.


Anke Weidenkaff
Anke Weidenkaff
studied chemistry at the University of Hamburg, Germany, and Pharmacy at the School for Chemistry and Pharmacy Lüneburg, Germany. She gained her Ph.D. in chemistry from the ETH Zurich, Switzerland, in 1999 and her habilitation from the University of Augsburg, Germany, in 2006.

After holding various positions at St. Cosmas Pharmacy, Endoklinik, Hamburg, Germany, the Paul Scherrer Institut PSI, Villigen, Switzerland, the University of Augsburg, Germany, and the University of Caen, France, Anke Weidenkaff became Head of the Solid-State Chemistry Group at Empa, Swiss Federal Laboratories for Materials Testing and Research Dübendorf, Switzerland, in 2003, a private lecturer PD at the University of Augsburg, Germany, in 2007, a professor at the Department of Chemistry and Biochemistry at the University of Bern, Switzerland, in 2008, the head of the laboratory for Solid State Chemistry and Catalysis at Empa in 2013, and a professor of chemical materials synthesis at the University of Stuttgart, Germany, in 2013.

Currently, Anke Weidenkaff is Professor at the Technische Universität Darmstadt and the Fraunhofer Project Group IWKS.


Selected Awards

  • 2011 Kavli Foundation Lectureship Award
  • 1998 SolarPACES Award


Selected Publications


A Special Collection on Circular Economy is jointly published by ChemPhysChem and Batteries & Supercaps; Currently, it is open for submissions.


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