Natural Sciences Colloquium
Students are welcome!
Dr. Neil Dasgupta
University of Michigan-Ann Arbor
Title: Interfacial Engineering of Energy Conversion and Storage Materials at the Nanoscale
There has been a dramatic increase in research of nanoscale materials for energy conversion and storage devices due to several advantageous features such as high surface areas, short transport distances, and tunable material properties. However, with these benefits come challenges. In particular, the ability to precisely control the properties of surfaces and heterogeneous interfaces limits the performance of many of these devices, and requires novel approaches. Additionally, the ability to manufacture materials with precise control of heterogeneous features in three dimensions and at length scales spanning from atoms to meters is challenging, requiring complementary processing techniques. To bridge this gap requires novel approaches to design material systems across these length scales, allowing us to fabricate hierarchical structures with deterministic control of geometric and chemical properties.
To address this challenge, our research group focuses on the atomically-precise modification of surfaces and interfaces to control material assembly and transport phenomena across physical and chemical boundaries. Examples include surface passivation against undesirable reactions at electrode-electrolyte interfaces in batteries, the integration of atomic clusters as catalysts with tunable sizes for solar-to-fuel conversion, and ‘bottom-up’ synthesis of textured surfaces for tunable wettability of fluids. The key enabling technology that is used for surface modification is Atomic Layer Deposition (ALD). This is a gas-phase deposition process capable of conformally coating high aspect-ratio structures with sub-nanometer control in thickness. This atomic-scale modification of surfaces allows for precise control of interactions at heterogeneous interfaces, which can be used to direct self-assembly processes, provide tunability of the optical, electronic, thermal, and mass transport properties of integrated material systems, and encapsulate structures to promote their stability in a wide range of environments. In this talk, I will demonstrate examples of the ALD process for modification of electrode-electrolyte interfaces with an emphasis on “beyond Li-ion” batteries and solar-to-fuel conversion, and provide a perspective on how this versatile approach can lead to the design and manufacturing of material systems with precision at length scales ranging from atoms to meters.