HZB Newsroom

In June and July 2025, catalyst researcher Nico Fischer spent some time at HZB. It was his sabbatical, he was relieved of his duties as Director of the Catalysis Institute in Cape Town for several months and was able to focus on research only. His institute is collaborating with HZB on two projects that aim to develop environmentally friendly alternatives using innovative catalyst technologies. The questions were asked by Antonia Rötger, HZB.

Scientists at HZB run a long-term experiment on the roof of a building at the Adlershof campus. They expose a wide variety of solar cells to the weather conditions, recording their performance over a period of years. These include perovskite solar cells, a new photovoltaic material offering high efficiency and low manufacturing costs. Dr Carolin Ulbrich and Dr Mark Khenkin evaluated four years of data and presented their findings in Advanced Energy Materials. This is the longest series of measurements on perovskite cells in outdoor use to date. The scientists found that standard perovskite solar cells perform very well during the summer months, even over several years, but decline in efficiency during the darker months.

Li-ion and Na-ion batteries operate through a process called intercalation, where ions are stored and exchanged between two chemically different electrodes. In contrast, co-intercalation, a process in which both ions and solvent molecules are stored simultaneously, has traditionally been considered undesirable due to its tendency to cause rapid battery failure. Against this traditional view, an international research team led by Philipp Adelhelm has now demonstrated that co-intercalation can be a reversible and fast process for cathode materials in Na-ion batteries. The approach of jointly storing ions and solvents in cathode materials provides a new handle for designing batteries with high efficiency and fast charging capabilities. The results are published in Nature Materials.

UNITE – Startup Factory Berlin-Brandenburg has been recognised by the Federal Ministry for Economic Affairs and Energy as one of ten nationwide flagship projects for science-based start-ups. UNITE is to be established as a central transfer platform for technology-driven spin-offs from science and industry in the capital region. The Helmholtz Centre Berlin will also benefit from this.

Helmholtz-Zentrum Berlin was delighted to welcome nearly 4,000 visitors to its Adlershof campus for the Long Night of the Sciences. It was a fantastic celebration of science, and we thank all our guests for their great interest.

The South African chemist Denzil Moodley is the first Industrial Research Fellow at HZB. He is playing a leading role in the CARE-O-SENE project. The Fellowship program aims to further accelerate the development of an efficient catalyst for a sustainable aviation fuel. An interview about the CARE-O-SENE project and why it is so important for scientists from industry and public research to work together.

The Federal Institute for Materials Research and Testing (BAM), the Helmholtz-Zentrum Berlin (HZB), and Humboldt University of Berlin (HU Berlin) have signed a memorandum of understanding (MoU) to establish the Berlin Battery Lab. The lab will pool the expertise of the three institutions to advance the development of sustainable battery technologies. The joint research infrastructure will also be open to industry for pioneering projects in this field.

Lithium button cells with electrodes made of nickel-manganese-cobalt oxides (NMC) are very powerful. Unfortunately, their capacity decreases over time. Now, for the first time, a team has used a non-destructive method to observe how the elemental composition of the individual layers in a button cell changes during charging cycles. The study, now published in the journal Small, involved teams from the Physikalisch-Technische Bundesanstalt (PTB), the University of Münster, researchers from the SyncLab research group at HZB and the BLiX laboratory at the Technical University of Berlin. Measurements were carried out in the BLiX laboratory and at the BESSY II synchrotron radiation source.

Clathrates are characterised by a complex cage structure that provides space for guest ions too. Now, for the first time, a team has investigated the suitability of clathrates as catalysts for electrolytic hydrogen production with impressive results: the clathrate sample was even more efficient and robust than currently used nickel-based catalysts. They also found a reason for this enhanced performance. Measurements at BESSY II showed that the clathrates undergo structural changes during the catalytic reaction: the three-dimensional cage structure decays into ultra-thin nanosheets that allow maximum contact with active catalytic centres. The study has been published in the journal ‘Angewandte Chemie’.

In 2023, photovoltaic systems generated more than 5% of the world’s electrical energy and the installed capacity doubles every two to three years. Optical technologies can further increase the efficiency of solar modules and open up new applications, such as coloured solar modules for facades. Now, 27 experts provide a comprehensive overview of the state of research and assess the most promising innovations. The report, which is also of interest to stakeholders in funding and science management, was coordinated by HZB scientists Prof. Christiane Becker and Dr. Klaus Jäger.

Dr. Moses Alfred Oladele is working on photocatalysis for CO₂ conversion in a joint project with the group of Dr. Matt Mayer, HZB, and Prof. Andreas Taubert at the University of Potsdam. The chemist from Redeemer's University in Ede, Nigeria, came to Berlin in the summer of 2024 with a Georg Forster Research Fellowship from the Alexander von Humboldt Foundation and will work at HZB for two years.

In the COMET-PV project, Dr Artem Musiienko aims to significantly accelerate the development of perovskite solar cells. He is using robotics and AI to analyse the many variations in the material composition of tin-based perovskites. The physicist will set up a Young Investigator Group at HZB. He will also have an affiliation with Humboldt University in Berlin, where he will gain teaching experience in preparation for a future professorship.

Frankfurt, 06. März 2025 – Die führenden deutschen Solarforschungseinrichtungen, die Fachabteilung „Photovoltaik Produktionsmittel“ des Industrieverbands VDMA und das Produktionsplanungs-Unternehmen RCT Solutions, haben ein gemeinsames Positionspapier zur Stärkung der deutschen und europäischen Solarindustrie veröffentlicht. Dieses wird nun an die Parteien übermittelt, die nach der Bundestagswahl im Bundestag vertreten sind. Ziel ist es, die vorgeschlagenen Maßnahmen in die Koalitionsverhandlungen einzubringen und damit die Grundlage für eine widerstandsfähige und wettbewerbsfähige Solarindustrie in Deutschland zu schaffen.

Metal-based electrodes in lithium-ion batteries promise significantly higher capacities than conventional graphite electrodes. Unfortunately, they degrade due to mechanical stress during charging and discharging cycles. A team at HZB has now shown that a highly porous tin foam is much better at absorbing mechanical stress during charging cycles. This makes tin foam an interesting material for lithium batteries.

Perovskite solar cells are highly efficient and low cost in production. However, they still lack stability over the decades under real weather conditions. An international research collaboration led by Prof. Antonio Abate has now published a perspective on this topic in the journal Nature Reviews Materials. They explored the effects of multiple thermal cycles on microstructures and interactions between different layers of perovskite solar cells. They conclude that thermal stress is the decisive factor in the degradation of metal-halide perovskites. Based on this, they derive the most promising strategies to increase the long-term stability of perovskite solar cells.

Within the CARE-O-SENE project, HZB is cooperating with the South African company Sasol on innovative catalysts for sustainable aviation fuels (SAF). Now, the collaboration is intensifying: Dr. Denzil Moodley, a leading scientist in the field of Fischer-Tropsch at Sasol Research and Technology, is being appointed as Industrial Research Fellow at HZB. Moodley will contribute his expertise at HZB with the aim of accelerating the innovation cycle for sustainable fuel technologies.

Combining two semiconductor thin films into a tandem solar cell can achieve high efficiencies with a minimal environmental footprint. Teams from HZB and Humboldt University Berlin have now presented a CIGS-perovskite tandem cell that sets a new world record with an efficiency of 24.6%, certified by the independent Fraunhofer Institute for Solar Energy Systems.

The Science Year 2025 is dedicated to the topic of ‘Future Energy’ and the Helmholtz Association is conducting cutting-edge research in this field.  An interview with Bernd Rech, Vice-President Energy of the Helmholtz Association and Scientific Director at HZB, on topics such as: Where does Germany stand with the restructuring of its energy system? What contribution can research make? And what about hydrogen, nuclear energy and nuclear fusion, and the new challenges for a secure supply in times of cyber attacks?

A team from HZB and the Fraunhofer Institute for Material and Beam Technology (IWS) in Dresden has gained new insights into lithium-sulphur pouch cells at the BAMline of BESSY II. Supplemented by analyses in the HZB imaging laboratory and further measurements, a new picture emerges of processes that limit the performance and lifespan of this industrially relevant battery type. The study has been published in the prestigious journal Advanced Energy Materials.

Iridium-based catalysts are needed to produce hydrogen using water electrolysis. Now, a team at HZB has shown that the newly developed P2X catalyst, which requires only a quarter of the Iridium, is as efficient and stable over time as the best commercial catalyst. Measurements at the EMIL lab at BESSY II have now revealed how the special chemical environment in the P2X catalyst during electrolysis promotes the oxygen evolution reaction during water splitting.

38,000 visitors in 20 years: high demand shows need for science education

Twenty years ago, on 29 November 2004, Klaus Böger, then Senator for Education in Berlin, opened one of the capital's first school laboratories. Since then, Helmholtz-Zentrum Berlin (HZB), in cooperation with the Berlin Senate, has successfully promoted science education through project days and further training in the school lab.

New cathode materials are being developed to further increase the capacity of lithium batteries. Multilayer lithium-rich transition metal oxides (LRTMOs) offer particularly high energy density. However, their capacity decreases with each charging cycle due to structural and chemical changes. Using X-ray methods at BESSY II, teams from several Chinese research institutions have now investigated these changes for the first time with highest precision: at the unique X-ray microscope, they were able to observe morphological and structural developments on the nanometre scale and also clarify chemical changes.

Bio-based thermoplastics are produced from renewable organic materials and can be recycled after use. Their resilience can be improved by blending bio-based thermoplastics with other thermoplastics. However, the interface between the materials in these blends sometimes requires enhancement to achieve optimal properties. A team from the Eindhoven University of Technology in the Netherlands has now investigated at BESSY II how a new process enables thermoplastic blends with a high interfacial strength to be made from two base materials: Images taken at the new nano station of the IRIS beamline showed that nanocrystalline layers form during the process, which increase material performance.

A team from the Technical University of Berlin, HZB, IMTEK (University of Freiburg) and Siemens Energy has developed a highly efficient alkaline membrane electrolyser that approaches the performance of established PEM electrolysers. What makes this achievement remarkable is the use of inexpensive nickel compounds for the anode catalyst, replacing costly and rare iridium. At BESSY II, the team was able to elucidate the catalytic processes in detail using operando measurements, and a theory team (USA, Singapore) provided a consistent molecular description. In Freiburg, prototype cells were built using a new coating process and tested in operation. The results have been published in the prestigious journal Nature Catalysis.

Ten teams at Helmholtz-Zentrum Berlin are building a long-term international alliance to converge practices and develop reproducibility and comparability in perovskite materials. The TEAM PV project is funded by the Federal Ministry of Education and Research (BMBF), Germany.

At HZB, 117 postdocs from 29 countries are employed. They play a crucial role in driving the main research activities, fostering creativity and innovation. To honor them, the Postdoc Appreciation Week was first organised in the USA in 2009 and has in the meantime become a regular event in Germany as well in the third week of September every year.

The MXene class of materials has many talents. An international team led by HZB chemist Michelle Browne has now demonstrated that MXenes, properly functionalised, are excellent catalysts for the oxygen evolution reaction in electrolytic water splitting. They are more stable and efficient than the best metal oxide catalysts currently available. The team is now extensively characterising these MXene catalysts for water splitting at the Berlin X-ray source BESSY II and Soleil Synchrotron in France.