Gruppenfoto von Polis

Batteries are one of the key technologies of the next decades. Lithium-ion batteries have not only enabled the consumer electronics revolution, they are also about to enable electric-driven transportation and will substantially contribute to the energy transition (“Energiewende”), providing intermediate storage of electric energy for efficient use of intermittent renewables such as solar or wind in decentralized facilities.

Lithium-ion batteries are currently the best battery option as they offer high voltages and thus high energy densities. However, the battery chemicals used are not sustainable in the medium and long term. The extraction of components such as cobalt, graphite and lithium involves political, ecological and economic risks. The European Commission fears supply bottlenecks due to scarcity of resources and the uncertain political situation of some countries with large reserves. Moreover, in many cases the mining of cobalt takes place under degrading conditions and is associated with high environmental impacts.

The Cluster of Excellence POLiS develops the necessary new battery materials and technology concepts for efficient and sustainable storage of electrical energy. We have identified sustainable alternatives that no longer rely on lithium and other critical materials: We are researching batteries based on sodium, magnesium, calcium, aluminium and chloride ions. These so-called post-lithium batteries have the potential to store more energy, be safer, and offer a more cost-effective, long-term option for mass applications such as stationary and mobile electrochemical storage.

With this concept, the Karlsruhe Institute of Technology (KIT), the  Ulm University, the Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) and the University of Giessen have asserted themselves in the Excellence Strategy of the Federal Government and the Länder - as the only German Cluster of Excellence for battery research. POLiS is funded with 47 million euros over seven years.

History of POLiS

Synergies of Karlsruhe and Ulm Battery Research

The collaboration of Ulm University and Karlsruhe University dates back to the 1980s, where several research groups collaborated on various aspects of electrochemistry. More than 20 years later, Germany began aiming at playing a major international role in research and development of modern batteries, and electrochemistry – a topic that had been dormant for a while – gained tremendous attention again.

Motivated by these circumstances, a group of scientists from Ulm and Karlsruhe led by Horst Hahn from the Institute of Nanotechnology at KIT met at the scenic Reisensburg in spring 2010, to discuss the structure and content of a new and joint effort in the field of Electrochemical Energy Storage. In September 2010, a proposal was submitted to the German Helmholtz Association of Research Centers, with the aim to establish a new institute. The proposal was evaluated by an international review commission and granted in November 2010.

Already in January 2011, the Helmholtz-Institute Ulm for Electrochemical Energy Storage (HIU) was founded. The institute is carried by KIT as legal entity, with Ulm University as partner and ZSW Ulm and DLR as associate partners. In the following years, HIU took an active role in driving and strengthening the collaboration between the partners and attracted researchers from all over the world who wanted to work at the forefront of electrochemical energy storage.

Building on the successful work and collaboration within the HIU, a first suggestion for a joint proposal was sent to the boards of KIT and Ulm University in spring 2016, with the aim to participate in the new German Excellence Strategy and apply for a Cluster of Excellence on “Energy Storage Beyond Lithium”. The idea was selected and eventually became one of the first stage proposals submitted in February 2017. Besides KIT and UUlm, also ZSW Ulm and the Justus-Liebig University in Giessen were partners in the consortium. Our joint proposal on “Energy Storage Beyond Lithium” was approved by the reviewers of the German Science Foundation (DFG) in September 2017, and we became the only purely battery-related consortium to enter the second stage.

The following months were dedicated to build the main structure of the work, filling the aims and claims with life and then to submit the final version of approx. 200 pages in February 2018. Soon after, in April 2018, the consortium was invited to defend the proposal in front of 20 international referees selected by DFG. Our proposal and presentation were able to convince the reviewers, so that the activity was among those which were set on “green” in the final round. The final decision came in Sept. 28, 2018 and the Excellence Cluster Post-Lithium Storage (POLiS) was selected among 58 other proposals in Germany to receive funding for approx. 100 researchers over 7 years, starting from January 1st, 2019.

POLiS is also embedded in the Center for Electrochemical Energy Storage Ulm and Karlsruhe (CELEST), founded in 2018 by KIT, Ulm University and ZSW. CELEST conducts research in all areas of electrochemical energy storage and covers the entire research and development chain from basic research to technology transfer. With 31 institutes and 46 working groups of its three partners, CELEST represents one of the largest research platforms on this topic worldwide.



Karlsruhe Institute of Technology

KIT combines the traditions of a renowned technical university and a major large-scale research institution in a very unique way. In research and education, KIT assumes responsibility for contributing to the sustainable solution of the grand challenges that face the society, industry, and the environment. For this purpose, KIT uses its financial and human resources with maximum efficiency. The scientists of KIT communicate the contents and results of their work to society.

Engineering sciences, natural sciences, the humanities, and social sciences make up the scope of subjects covered by KIT. In high interdisciplinary interaction, scientists of these disciplines study topics extending from the fundamentals to application and from the development of new technologies to the reflection of the relationship between man and technology. For this to be accomplished in the best possible way, KIT’s research covers the complete range from fundamental research to close-to-industry, applied research and from small research partnerships to long-term large-scale research projects. Scientific sincerity and the striving for excellence are the basic principles of our activities.

Worldwide exchange of knowledge, large-scale international research projects, numerous global cooperative ventures, and cultural diversity characterize and enrich the life and work at KIT. Academic education at KIT is guided by the principle of research-oriented teaching. Early integration into interdisciplinary research projects and international teams and the possibility of using unique research facilities open up exceptional development perspectives for our students.

The development of viable technologies and their use in industry and the society are the cornerstones of KIT’s activities. KIT supports innovativeness and entrepreneurial culture in various ways. Moreover, KIT supports a culture of creativity, in which employees and students have time and space to develop new ideas.

Ulm University

Ulm University was founded in 1967 . An attractive and seminal course catalogue, high standard of education, internationality, interdisciplinarity and top-level innovative research have become trademarks of Ulm University.

Ulm University is being funded in battery research by the Excellence Strategy of the federal and state governments.  

Over 10,000 students receive thorough education and support in 4 faculties . The Faculties of Medicine, Natural Sciences, Mathematics and Economics and Engineering, Computer Sciences and Psychology offer more than 60 study programmes , some of them taught in English. Internationally , Ulm University stands out with its particularly comprehensive support for international students. The quality of teaching has a high priority at Ulm University. Quality standards and goals are settled in the Teaching Mission Statement .

Continuing academic education  offers qualifications for working professionals. Modularised master’s programmes teach specialised skills as well as management know how, research expertise and leadership skills. Their didactic concept is based on actual results from teaching and learning research.

Ulm University is a green campus university and belongs to a dynamic region with a strong economy. The University is an important driving force behind the Science City Ulm  and partner  in numerous cooperations  with industry, economy and other institutions on a regional, national and international level.

Ulm University dedicates itself to 12 strategic research topics , most of which are interdisciplinary. Important research fields are the life sciences and medicine, bio-, nano- and energy materials, financial services and their mathematical methods as well as information, communication and quantum technologies.

Associated Partners

University of Gießen

Founded in 1607, Justus Liebig University Giessen (JLU) is a traditional research university that attracts over 28,000 students. In addition to a wide range of courses - from classical natural sciences, law and economics, social sciences and educational sciences to linguistics and cultural studies - it offers a spectrum of life sciences that is unique not only in Hessen: human and veterinary medicine, agricultural, environmental and nutritional sciences as well as food chemistry. Among the great personalities who have researched and taught at JLU are a number of Nobel Prize winners, including Wilhelm Conrad Röntgen (Nobel Prize for Physics 1901) and Wangari Maathai (Nobel Peace Prize 2004).

Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW)

The ZSW was established in 1988 by the German state of Baden-Württemberg, together with universities, research institutions, and commercial firms. It is a non-profit foundation under the civil code. Solar energy and hydrogen technologies are currently maturing on an industrial scale and will be major components in the sustainable energy supply of the 21st century. As a result, ZSW pursues the following goals and research topics.

The ZSW's research goals are:
  • Research and development of technologies for the sustainable and climate-friendly generation of electricity, heat, and fuel
  • Transfer of R&D results to market-relevant products (technology transfer)
  • Consulting political decision-makers and professional associations

Today the ZSW has approximately 230 employees and 70 student and scientific assistants and is one of the leading energy research institutes in Europe. Joint ventures and the growing proportion of industry commissions demonstrate the consistent applications relevance of our work.


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