Scientific Events

Electrochemical Capacitance under Confinement: Implications for Electrochemical Energy Storage and Conversion

Electrochemical Capacitance under Confinement: Implications for Electrochemical Energy Storage and Conversion
Abstract: Many layered materials of interest for electrochemical energy storage and conversion applications are flexible hosts whose interlayers can be expanded to accommodate not just ions but also solvents, organic molecules, polymers, and organometallics. When these “hybrid” materials are placed into an electrochemical environment, the distinction between surface and bulk becomes blurred since the electrochemical interface can now be viewed to extend into the interlayer. During this seminar, I will discuss fundamental aspects of charge storage at electrochemical interfaces and how interfacial charge storage and reactivity change under confinement. I will also describe synthesis of hybrid layered materials and the use of in situ and operando characterization to understand the relationships between structure and composition and the resulting electrochemical reactivity. [more]

Artificial Intelligence for Engineering Design and Computational Mechanics

Engineered systems are an indispensable part of our modern life with far-reaching applications that include aerial and ground transportation, electronics, large-scale structures, and medicine. The ever-evolving societal, environmental, and cultural awareness calls for significantly complex systems with unprecedented properties that reliably meet stakeholders’ demands under extreme conditions. To accelerate the design and deployment of such systems while reducing the reliance on costly and time-consuming experiments, it is necessary to develop advanced computational methods that streamline their design and analysis process. In this talk, I will present some of our recent works for solving challenging problems in engineering design, solid mechanics, and fluid dynamics. In particular, I will demonstrate how we can (1) accelerate multiscale simulations of casting materials ten times via mechanistic reduced order models, (2) surrogate plastic and history dependent deformation of fiber composites with deep learning, (3) optimize material composition with latent map Gaussian processes and Bayesian optimization, and (4) solve partial differential equations with transfer learning. [more]

STZ vortex unit – the key to understand and control shear banding in metallic glasses

Transition to a Group Leader position at a German University

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

Metal energy carriers: renewable fuels of the future

Metal powder has superior energy density compared to fossil fuels and hydrogen. Therefore, metal powders have gained interest as a material for energy storage. The main benefits of metal fuels are that they do not produce CO2 emissions during combustion, they have the potential to be retrofitted in existing coal power plants and they can fit into the existing fuel transportation infrastructure. Furthermore, this enables the production of sustainable energy since metal fuels can be regenerated from metal oxides, using hydrogen from renewable sources. In this presentation, the main characteristics of metal fuels are presented with a final focus on clean combustion. A series of burners has been developed: - single particle or fuel jet in a micro burner to study single particle combustion and particle-particle interaction - Bunsen-type burner for stabilizing laminar and weakly turbulent premixed flames - Tornado-swirl burner First numerical studies are also started for comparison. Furthermore, a 100 KW demonstrator set-up is developed to demonstrate clean combustion to produce steam (placed at Swinkels brewery and Metalot centre). Studies to scale up are also conducted. The main objective of this practical systems is the development of an integrated flexible metal fuel burner with a capacity of 100 KW (TRL5). This is an essential step towards implementation of this sustainable technology. This project forms the basis to further develop full scale burners with a capacity of 10 MWth. The development of the prototype burner is executed by a consortium which covers the entire supply chain. This includes the production of metal powder, fuel preparation, burner and combusted product handling. The industrial partners have broad experience in metal powder supply, dense energy carriers and operating coal fired power plants. Furthermore, techno-economic analyses and the assessment of retrofit potential to existing assets will be carried out. Status-quo will be presented [more]

Growth of Mg-aluminate spinel at MgO- Al2O3 contacts: experiment, nature, and some theory

In this presentation the formation of spinel (MgAl2O4) by reaction between periclase (MgO) and corundum (Al2O3) is addressed. The reaction MgO + Al2O3 => MgAl2O4 may be regarded as a model case for diffusive phase transformations in oxide systems. All phases involved are moderately to highly refractory and have applications in ceramics. Above about 800°C, periclase and corundum react to form a layer of polycrystalline spinel at their interface. A pronounced dichotomy of the internal microstructure and texture of the spinel layer reveals the original position of the periclase-corundum interface. This reflects the direction and extent of the necessary Mg2+ and Al3+ transfer across the spinel layer and allows to quantify the underlying diffusion process. Systematic deviations of the Mg/Al ratio of the spinel from local equilibrium values at the spinel-periclase and the spinel-corundum interface are due to a finite mobility of the two reaction interfaces. The resistance against interface motion arises from dislocation climb at the periclase-spinel interface, which is complemented by the formation of Schottky defects in the reactant periclase. In contrast, the corundum-spinel interface moves by the glide of partial dislocations. This is energetically less expensive than the dislocation climb at the periclase-spinel interface and allows for comparatively rapid approximation of local equilibrium. [more]

Micromechanics of large deformations

Show more
Go to Editor View