Scientific Events

In order to address climate change, we must transition to a low-carbon economy. Many clean primary energy sources, such as solar panels and wind turbines, are being deployed and promise an abundant supply of clean electricity in the near future. The key question becomes how to store, transport and trade this clean energy in a manner that is as convenient as fossil fuels. The Alternative Fuels Laboratory (AFL) at McGill University is actively researching the use of recyclable metal fuels as a key enabling technology for a low-carbon society. Metal fuels, reduced using clean primary energy, have the highest energy density of any chemical fuel and are stable solids, simplifying trade and transport. The chemical energy stored in the metal fuels can be converted to useful thermal or motive power through two main routes: the Dry Cycle, where metal powders/sprays are burned with air, or the Wet Cycle, where metal powders are reacted with water to produce hydrogen and heat as an intermediate step before using the hydrogen as a fuel for various power systems. This talk will overview the concept of metal fuels and the various power system options. It will also touch on the combustion and reaction physics of metal fuels and the propagation of metal flames. [more]

Electrochemical energy storage is the key enabling component of electric vehicles and solar/wind-based energy technologies. The enhancement of energy stored requires the detailed understanding of ionic transport and electrochemical and electromechanical phenomena on local scales which are not always accessible with classical electrochemical techniques, such as voltammetry. Therefore, local probing of electrochemical and electromechanical behaviors on individual structural elements and heterogeneities, from grains to defects and further to individual atomic and molecular species, are invaluable. In this talk, I want to introduce force-based atomic force microscopies (AFM) to provided novel insights into local electrochemical processes on tens of nanometer and even molecular length under electrochemical control. I will highlight the development and application of in situ/operando force-based AFM methods to gain insight into the local charge storage mechanism in a variety of energy related materials. In the first part of the talk, I will showcase how AFM can be used to investigate the structure and dynamics of the electric double layer (EDL) for electrochemical capacitors. I want to highlight work on room temperature ionic liquids on model graphene electrodes since ionic liquids hold the promise of increasing the electrochemical stability windows for electrochemical capacitors. AFM was used to observe topological defects and show the existence of structural domains parallel to the solid-liquid interface towards a full picture of the double layer structure and their change with applied bias. In the second part of the talk, I want to highlight how AFM-based methods can be used to study ionic transport and local electrochemical reactions in supercapacitors and battery materials. Here, electro-chemo-mechanical coupling is the key to study ion insertion pathways and heterogeneities in local redox reactions. The first is demonstrated for the cation insertion into layered Ti3C2 electrodes based on their change in mechanical stiffness whereas the second is highlighted for proton insertion into WO3 where the relationship between electrochemical current and electrode strain are discussed. [more]

The advent of solid-state batteries has spawned a recent increase in interest in lithium conducting solid electrolytes. However, many open questions remain when trying to optimize electrolytes and understand solid state battery chemistries. In this presentation, we will show how an understanding of the structure-transport properties can help tailor the ionic conductivity. In an exemplary study on superionic lithium metal halides, we show that a cation site-disorder and the local structure of materials is important to study, especially as synthetic influences control materials properties. In a second part of this presentation, we will show the tremendous influence of lattice dynamics on ionic conductors. By introducing a different approach to understanding ionic motion using phonon occupations, we try to explain so far unexplained behaviors of physical ionic transport. Finally, we will show that it is not only important to find fast ionic conductors, but that fast ionic conduction is paramount within solid state battery composites. Measuring the effective ionic transport in cathode composites provides an avenue to explore transport and stability limitations that in turn provide better criteria for solid state battery performance Bio: Wolfgang Zeier received his doctorate in Inorganic Chemistry in 2013 from the University of Mainz. After postdoctoral stays at the University of Southern California, the California Institute of Technology, and Northwestern University, he was appointed group leader at the University of Giessen, within the framework of an Emmy-Noether research group. Since 2020 he holds a professorship for Inorganic Chemistry at the University of Münster. In addition, he heads a department at the Helmholtz-Institute Münster, Ionics in Energy Storage. His research interests encompass the fundamental structure-to-property relationships in solids, with a focus on thermoelectric and ion-conducting materials, as well as solid-solid interfacial chemistry for all-solid-state batteries. [more]

The NanoSIMS is emerging as a powerful tool to study complex problems in materials science. The NanoSIMS is a high-resolution secondary ion mass spectrometry instrument capable of chemical mapping at 100 nm spatial resolution, detection limits in the ppm range and is able to detect almost all elements in the periodic table as well as isotopes. In this seminar I will show how we have been using the NanoSIMS to image localised deuterium in electrochemically charged steel and nickel alloys as well as in zirconium alloys oxidised in an autoclave to simulate nuclear reactor conditions. I will explain how isotopic tracers, such as 18O and deuterium, can be used to avoid imaging artefacts and provide temporal information. Some of the complexities associated with detecting hydrogen and deuterium in the NanoSIMS will be discussed. [more]

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In order to address climate change, we must transition to a low-carbon economy. Many clean primary energy sources, such as solar panels and wind turbines, are being deployed and promise an abundant supply of clean electricity in the near future. The key question becomes how to store, transport and trade this clean energy in a manner that is as convenient as fossil fuels. The Alternative Fuels Laboratory (AFL) at McGill University is actively researching the use of recyclable metal fuels as a key enabling technology for a low-carbon society. Metal fuels, reduced using clean primary energy, have the highest energy density of any chemical fuel and are stable solids, simplifying trade and transport. The chemical energy stored in the metal fuels can be converted to useful thermal or motive power through two main routes: the Dry Cycle, where metal powders/sprays are burned with air, or the Wet Cycle, where metal powders are reacted with water to produce hydrogen and heat as an intermediate step before using the hydrogen as a fuel for various power systems. This talk will overview the concept of metal fuels and the various power system options. It will also touch on the combustion and reaction physics of metal fuels and the propagation of metal flames. Bio: Jeffrey Bergthorson is the Panda Faculty Scholar in Sustainable Engineering and Design, and a Professor in the Department of Mechanical Engineering, at McGill University where he leads the Alternative Fuels Laboratory. He received his B.Sc. in Mechanical Engineering from the University of Manitoba (1999), and his M.Sc. (2000) and Ph.D. (2005) in Aeronautics from the Graduate Aeronautical Laboratories of the California Institute of Technology. Prof. Bergthorson is a Fellow of the Combustion Institute and a Fellow of the American Society of Mechanical Engineers. Prof. Bergthorson’s research interests are in the broad area of the combustion and emissions properties of alternative and sustainable fuels, including biofuels, hydrogen, and the use of metals as recyclable fuels. [more]

The photovoltaic (PV) industry is in rapid growth and a large supply of PV feedstock materials must be provided to maintain this growth. Since silicon is the dominant material for the fabrication of solar cells, low-cost solar-grade silicon (SoG-Si) feedstock is demanded. The most cost-effective and direct approach for producing SoG-Si is to purify and upgrade metallurgical-grade silicon (MG-Si). Many impurities in MG-Si can be effectively removed through directional solidification of molten silicon. However, the removal of boron (B) and phosphorus (P) by this method is difficult and expensive due to the relatively large distribution coefficients of these elements. Therefore, the elimination of B and P to the levels required for SoG-Si feedstock requires the development of new processes. In the present study, the effect of impurities on the solar cell efficiencies and the impurity contents in silicon materials are studied. The metallurgical processes that can be applied to purify metallurgical silicon to solar grade silicon are reviewed and evaluated. It is shown that under development metallurgical refining processes are applicable to produce solar grade silicon. [more]