With the increased significance of lithium-ion batteries, the pressure on the availabiltity of relevant ressources rises. Especially, lithium and cobalt are fundamental components of present lithium-ion batteries. A recent analysis of a research team led by Dr. Daniel Buchholz and Prof. Dr. Stefano Passerini shows that the availability of both elements could become seriously critical. Cobalt-free battery technologies, including post-lithium technologies based on non-critical elements such as so-dium, but also magnesium, zinc, calcium and aluminium, represent possibilities to decrease the dependency and avoid the crit-icality of lithium and Co.

The researchers present these results in the journal Nature Reviews Materials. In addition, the publication will be part of the Nature Reviews Materials online collection Chemistry at the nexus of water and energy, which contains selected articles from the field of natural science.

Further information can be found in the current press release.

The transition to renewable energy challenges battery researchers to develop suitable energy storage technologies. Lithium-ion batteries are currently the most widely used battery technology for various applications, including electric vehicles. For their establishment, however, further improvements are necessary regarding their safety, performance and charging times.

Within a perspective assessment, representatives of the four leading national economies – USA, China, Japan and Germany – Perspectives of automotive battery R&D in China, Germany, Japan, and the USA address these issues, highlight the present state-of-the-art and provide and overview of the current and future developments with a particular focus on the funding programs of these four countries.

The release is the result of the annual International Conference on Advanced Lithium Batteries for Automobile Applications (ABAA), which took place in October last year, and has the aim to foster the exchange between industry and research institutions.

The perspective article is freely available online for anyone to access until 8 December 2018.

On May 2nd, a delegation of 10 members of the Electrochemical Society (ECS) Student Chapter of the Technical University of Munich (TUM) visited Ulm´s ECS Student Chapter, which is the youngest and -after Munich- the second student chapter of the ECS in Germany. Founded at the beginning of this year, the members the Student Chapter Ulm are currently PhD students from different electrochemical research groups, e.g. from the Helmholtz Institute Ulm (HIU), Center for Solar Energy and Hydrogen Research (ZSW) and Ulm University (UU). At the ZSW in Ulm, the lab-tour took the participants via the 10.000 m² ZSW Laboratory for Battery Technologies (eLaB) over to the H2 filling station and to the laboratories for hydrogen analysis, as well as to the fuel cell test center. At the HIU the lab-tour and a presentation displayed the combination of fundamental and applied research. During this meeting, both Student Chapters from Munich and Ulm could not only start networking on shared scientific topics, but they were also able to start planning future events, to improve the interdisciplinary competence of every student, according to the ECS guidelines:

“The mission of an ECS student chapter is to provide students the opportunity to foster a greater understanding as well as promote electrochemical and solid-state science and technology amongst its peers, to further enhance their professional development and to enrich their academic experience.”

Open to all graduate (PhD) students / Postdocs working on electrochemistry in the area of Ulm, the goals of the student chapter is to share and enlarge knowledge, as well as to establish collaborations amongst different research groups in the area of Ulm and the south of Germany. To become a member of the Student Chapter Ulm, you also have to be a member of the Electrochemical Society. ECS membership offers free access to ECS journals and discounts for ECS meetings and publishing fees. For Student Chapter Members, ECS membership is free.

Pictures of the event

The Karlsruhe Institute of Technology (KIT), the Ulm University (UUlm) and the Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) strengthen their collaboration in the area of Electrochemical Energy Storage. Founded on Jan 1, 2018, the Center for Electrochemical Energy Storage Ulm-Karlsruhe (CELEST) plans, prepares and organizes new joint endeavors in research, teaching, development and technology transfer. CELEST shall act as a platform to improve communication and to co-ordinate and further develop joint activities with other universities and research institutions as well as the industry, at home and abroad. With 30 institutes, which are active in the field of electrochemical energy storage, CELEST represents the largest research platform for this topic in Germany.

“CELEST is a logical next step in linking the Ulm and Karlsruhe locations more closely. The HIU as a joint institute of the KIT and the University of Ulm with its structure represents a nucleus of this now extended network”, emphasizes Maximilian Fichtner, director of HIU.

The expertise at both sites is complementary and ranges from basic research on the atomic scale to the largest pilot plant for cell production in Germany. The three institutions will co-operate on interdisciplinary research and development ranging from basic research to technical applications and on the qualification of students.

“CELEST places emphasis on Li-Ion technologyEnergy Storage Beyond Lithium and Alternative Techniques for Electrochemical Energy Storage and covers all current topics in this field. On the topic Energy storage beyond lithium the platform takes up a national and international top position, says Fichtner.

At the two-day biennial meeting with 120 participants, the researchers presented their research results of the last two years and discussed and decided on the direction for the future. The scientific exchange was tailored to the four HIU interdisciplinary topics – Metal Deposition and Interfaces, Insertion Materials and Electrode Structure, Lithium Based Conversion Materials and Alloys, Batteries Beyond Lithium. In each of the four topics, members of different research groups efficiently pool their competencies in this way.

Maximilian Fichtner and Stefano Passerini, Director and Deputy Director of the HIU, emphasized the numerous new international collaborations concluded in the last two years and the very good publication average with two publications per researcher per year. In addition, the up to now successful application for the federal government’s excellence strategy and the establishment of the battery research platform CELEST make optimistic for future research work.

The Kick-off meeting of CELEST and the first general assembly of its members took place at the HIU, Ulm. The CELEST members elected the spokespersons of the three research areas, actively discussed joint projects and decided on future activities and strategies for the research platform. The CELEST steering committee nominated Prof. Maximilian Fichtner as director of CELEST and Prof. Helmut Ehrenberg as deputy director of the center. The meeting laid a strong foundation for fruitful collaboration and impressively illustrated the broad range of scientific competences gathered among the CELEST members, paving the way for new joint endeavors in electrochemical energy storage.

The article “Aqueous/Non-aqueous Hybrid Electrolyte for Sodium-ion Batteries” is among the most read articles for the past month on the website of the journal ACS Energy Letters.

 

The team of researchers directed by Stefano Passerini reported an aqueous/nonaqueous hybrid electrolyte based on sodium trifluoromethanesulfonate with an expanded electrochemical window up to 2.8 V and high conductivity (∼25 mS cm–1 at 20 °C). The hybrid electrolyte inherited the safety characteristic of aqueous electrolytes and the electrochemical stability of nonaqueous systems, enabling stable and reversible operation of the Na3V2(PO4)3/NaTi2(PO4)3 sodium-ion battery.

Dagmar Oertel will leave the HIU in mid-September to take on new professional challenges as Secretary General of the Union of German Academies of Sciences and Humanities. Since January 1, 2012, she has served as Managing Director and played a key role in creating an infrastructure at the HIU that enables innovative research. The institute was launched in a very short time in 2011 and has grown considerably to this day.  At Dagmar Oertel, all organizational threads ran together to make this process successful. She established an administration with 14 employees in the areas of personnel, finance, public relations, IT and technology. Since the beginning of her career at HIU, she has coordinated the construction of the new institute building on the part of HIU, which was constructed in October 2014 by the state of Baden-Württemberg with a volume of 12 million euros and 2,400 square meters. Her time as managing director also saw the inauguration of the solar power storage system in spring 2015, which combines modern high-performance batteries with intelligent control for grid-conserving feed-in.

Dagmar Oertel studied chemistry and earned her doctorate in economics and worked at the Office for Technology Assessment of the German Bundestag for more than ten years. In 2007, she moved to Karlsruhe and accompanied the founding process of the Karlsruhe Institute of Technology (KIT), where she was deputy head of the Strategy, Structure and Development Planning department in the KIT presidential staff from 2009.

The HIU research group led by Axel Groß has made it on the back cover of the journal Energy & Environmental Science of the Royal Society of Chemistry with its element-specific theory – why battery electrode materials differ in their propensity for growing dendrites. Burning mobile phones or electric cars bursting into flames are caused by the formation of dendrites in batteries. The results could help solve the safety problems with the shrub-like crystal structures that can cause short circuits.

The researchers looked for battery materials that do not form any dendrites at all. While lithium, zinc and sodium batteries often form these spark-inducing structures, magnesium and aluminum batteries are virtually dendrite-free. In order to better understand dendrite formation, they therefore looked for a connection between the self-diffusion barriers of different metals. These barriers are the interfaces that reduce the diffusion of an atom on a surface of the same element and determine how likely it is that metal atoms deposit on electrodes and cause dendrite growth.

By studying the different metals, Axel Groß and his team found that lithium ions have relatively high self-diffusion interfaces, which means that once they have diffused a gradient onto a surface, the lithium ions remain there and form a rough area. The dendrite then branches from this defect. This suggests that dendrite formation is an inherent property of this element. In comparison, metals such as magnesium have a very low self-diffusion barriers and form smooth surfaces, so dendrites occur much less frequently.

The theory was also discussed in a separate news item in Chemistry World:

https://www.chemistryworld.com/news/diffusion-barrier-data-to-help-batteries-ditch-the-dendrites/3009502.article

For more information: pubs.rsc.org/en/Content/ArticleLanding/2018/EE/C8EE01448E

The Analysis of the CO2 footprint and life‐cycle costs of different batteries for stationary applications by scientists from HIU and the Institute for Technology Assessment and Systems Analysis (ITAS), published in “Energy Technology”, has been named one of the journal’s best articles of the year 2017.

The article CO2 Footprint and Life‐Cycle Costs of Electrochemical Energy Storage for Stationary Grid Applications determines life-cycle costs and greenhouse gas emissions of different battery technologies within stationary applications. It is part of the special issue “Energy Research at Karlsruhe Institute of Technology”.

The authors use an innovative combination of life cycle assessment, uncertainty simulation and battery size optimization. In contrast to previous works, they apply dynamic load profiles for the optimization of the size and lifetime of batteries and consider the potential influence of future technology developments like changing electricity mix or battery price decreases. Lithium-Ion batteries are found to be among the most promising battery technologies, due to their high performance and comparatively long lifetime. Classic lead-acid batteries, although cheap on the first glimpse, are less recommendable for stationary applications due to their low lifetime and efficiency.