Title: New Materials Chemistries and Concepts in Self-Assembly for Nanophotonics and Solid-State Batteries
Abstract: Emerging concepts in materials synthesis are having deep impacts on both photonics and energy storage. I will present highlights in both areas from work in my group with a focus on 3D nanophotonics in the first area and solid-state batteries in the second.
Via multiphoton polymerization in nanoporous hosts, we are creating low-loss volumetric microscale gradient refractive index lenses, waveguides, and metamaterials with a resolution of better than one micron. Adjusting the laser exposure during printing enables 3D submicron control of the polymer infilling of the nanoporous host and thus the refractive index over a range of greater than 0.3 and chromatic dispersion tuning. A Luneburg lens operating at visible wavelengths, achromatic doublets, multicomponent optics, and subsurface 3D waveguides were all formed. Various optical elements were combined to create the building blocks for volumetric photonic integrated circuits.
Using new strategies in electrodeposition, we synthesize nearly dense, deterministically structured cathodes and anodes and then form these into solid-state batteries. On the cathode side, I will present our work on electrodeposited LiCoO2, NaCoO2, LiMn2O4, and other LTMO systems which provide near-theoretical capacities, and exceptional rate performances. I will also present our work on CVD and electrodeposited silicon anodes, a system that offers potential for both good rate performance and high energy densities. I will discuss how the crystallography of the electrode | solid-electrolyte interface impacts interfacial reactions, rate performance, and cycle life. Time permitting, I will also present our recent work on electrochemical recycling of solid-state battery materials.
Bio: Prof. Paul V. Braun is the Director of the Materials Research Laboratory, the Grainger Distinguished Chair in Engineering, and Professor of Materials Science and Engineering, Chemistry, Mechanical Sciences and Engineering, and Chemical and Biomolecular Engineering, at the University of Illinois Urbana-Champaign. Prof. Braun received his B.S. degree with distinction from Cornell University, and his Ph.D. in Materials Science and Engineering from the University of Illinois. Following a postdoctoral appointment at Bell Labs, Lucent Technologies, Prof. Braun joined the faculty of the University of Illinois Urbana-Champaign. Prof. Braun is a Fellow of the Materials Research Society, AAAS and the National Academy of Inventors. https://braun.matse.illinois.edu/people/paul-braun/
Host: Randall Goldsmith