Scientific Events

Electrochemical Energy Storage, in particular Li-Ion Batteries, have become one of the most important technological cornerstones for the current energy transition. The further development and progress in existing technology will depend on both, the introduction of new active electrode materials and the better understanding and mitigation of existing materials challenges. After an introduction in battery technology and the used materials, I will focus on a few examples where advanced characterization is able to bring new insights and better understanding of performance and degradation mechanisms. [more]

In 2020, every major company’s annual report contained the word digitalization, A.I. or industry 4.0. It is easy to perceive these as buzzwords, aimed at investors, but the reality is more complex: companies are expected to transform now, driven by the fear of becoming obsolete. As researchers, this exciting transition creates significant opportunities: huge amounts of data are becoming readily available, while computing power and machine learning (ML) algorithms are more accessible than ever. However, this is also leading to disproportionate hopes and expectations regarding the actual capabilities of such methods, that only a working knowledge of ML combined with technical expertise in your field can rationalize. As R&D engineers, this critical view will be expected from you. Since technical expertise has already been the focus of your professional career, the effort should therefore be put on acquiring a practical knowledge of ML, that is, what problems can be solved and how to solve them? In this talk, some applications of ML to solve industrial issues (predictive modeling, visualization, combination with physical models...) will be discussed. Furthermore, practical aspects, such as data preparation, models implementation and maintenance will be reviewed, with the aim of providing actual insights on the root causes of successes and failures of ML applied to the steelmaking process. [more]

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Bulk-type (inorganic) solid-state batteries are a promising next-generation energy-storage technology with the prospect of improving safety and enabling higher energy densities than conventional lithium-ion batteries [1]. Especially high-capacity, layered oxide cathode materials (NCM or related) and lithium thiophosphate superionic solid electrolytes are currently being considered for solid-state battery applications (at the positive electrode side). However, interfacial side reactions and chemo-mechanical degradation during cycling operation are major obstacles toward commercialization of “practical” cells. In this presentation, I will demonstrate the importance of tailoring Ni-rich NCM materials in terms of size and composition, among others, for improving the cycling performance of pelletized and slurry-cast cathodes [2-4]. In addition, I will show recent findings on the effects that coating chemistry and morphology have on the side reactions, including gas evolution, in high-loading cells [4-6]. [1] J. Janek, W.G. Zeier, Nat. Energy, 1 (2016) 16141. [2] F. Strauss, T. Bartsch, L. de Biasi, A.-Y. Kim, J. Janek, P. Hartmann, T. Brezesinski, ACS Energy Lett., 3 (2018) 992. [3] F. Strauss, L. de Biasi, A.-Y. Kim, J. Hertle, S. Schweidler, J. Janek, P. Hartmann, T. Brezesinski, ACS Mater. Lett., 2 (2020) 84. [4] J.H. Teo, F. Strauss, D. Tripković, S. Schweidler, Y. Ma, M. Bianchini, J. Janek, T. Brezesinski, Cell Rep. Phys. Sci., 2 (2021) 100465. [5] T. Bartsch, F. Strauss, T. Hatsukade, A. Schiele, A.-Y. Kim, P. Hartmann, J. Janek, T. Brezesinski, ACS Energy Lett., 3 (2018) 2539. [6] F. Strauss, J.H. Teo, J. Maibach, A.-Y. Kim, A. Mazilkin, J. Janek, T. Brezesinski, ACS Appl. Mater. Interfaces, 12 (2020) 57146.

What is the role of materials in today’s global economy as we deal with pressures from a growing population and a climate emergency? Aluminum production and usage helps provide food, shelter, health, transportation, and entertainment to the world. Achieving these goals in a “sustainable” manner dictates that our materials “will impact positively on society’s current needs and have no negative effects on future generations to enjoy the same benefits.’ Life cycle analyses (LCA) of materials and products generally rate aluminum’s sustainability positively from an accounting of the energy and usage costs through the product lifetime. While plastic packaging, in particular, receives well-deserved bad press for polluting our world, it is necessary for aluminum suppliers and users as well to use our energy-intensive metal wisely. The talk will review the current production and carbon emissions footprint for primary aluminum and the role of recycling and secondary operations in the industry. Note that the analysis will take into account the sources of energy (renewable or fossil fuel) in different parts of the world. What is the current state of aluminum primary production? What adaptations are taking place?What is the prospect for new aluminum production technology?How do buildings, transportation and packaging markets stand in regard to production, use, re-use and recycling?What are the roadblocks to maximizing re-use and recycling? possible approaches to close them?Is ‘Green aluminum’ an achievable target? [more]

The development and improvement of catalysts for chemical energy conversion, such as (photo-)electrocatalytic water splitting or alcohol oxidation, requires mechanistic understanding at theatomic/molecular level. In my talk I will address several examples for the application of densityfunctional theory calculations to model, understand and tailor the catalytic activity of anodematerials for water splitting. To disentangle the role of structural motifs, crystallographic orientationand dopants, I will focus on iron and cobalt containing transition metal oxides with spinel [1-3],corundum [4] vs. perovskite [5] structure. The aim is to establish a link between the energetic trendsand the underlying structural and electronic properties and to identify potential active sites. Afurther topic is the reduction of iron oxide surfaces and bulk via hydrogen adsorption [6] andincorporation.Funding by the German Research Foundation DFT within SPP 1613 and CRC TRR247 as well ascomputational time at the Leibniz Rechenzentrum and the supercomputer MagnitUDE at UDE isgratefully acknowledged.[1] K. Chakrapani, G. Bendt, H. Hajiyani, I. Schwarzrock, T. Lunkenbein, S. Salamon, J. Landers, H.Wende, R. Schlögl, R. Pentcheva, M. Behrens, S. Schulz, ChemCatChem. 9, 2988-2995, (2017)[2] H. Hajiyani, R. Pentcheva, ACS Catal. 8, 11773-11782 (2018)[3] Y. Peng, H. Hajiyani, R. Pentcheva, ACS Catal. 11, 5601–5613, (2021)[4] A.G. Hufnagel, H. Hajiyani, S. Zhang, T. Li, O. Kasian, B. Gault, B. Breitbach, T. Bein, D. Fattakhova-Rohlfing, C. Scheu, R. Pentcheva, Adv. Funct. Mater., 165, 1804472 (2018)[5] A. Füngerlings, A. Koul, M. Dreyer, A. Rabe, D. M. Morales, W. Schuhmann, M. Behrens, and R.Pentcheva, Chemistry - A European Journal, accepted.[6] G. S. Parkinson, N. Mulakaluri, Y. Losovyj, P. Jacobson, R. Pentcheva, and U. Diebold, Phys. Rev. B82, 125413 (2010).

Where: virtual on Zoom (link follows) [more]