Self-organizing Nano-architectured Materials: Applications and Functional Properties
Program Organizers: Yu-chen Karen Chen-Wiegart, Stony Brook University / Brookhaven National Laboratory; Ian Mccue, Northwestern University; Erica Lilleodden, Fraunhofer Insitute for Microstructure of Materials and Systems (IMWS); Pierre-Antoine Geslin, CNRS / INSA-Lyon; Qing Chen, Hong Kong University of Science & Technology
Wednesday 10:00 AM
March 2, 2022
Room: 260C
Location: Anaheim Convention Center
Session Chair: Erkin Seker, University of California - Davis; Ian Mccue, Northwestern University
10:00 AM
Coarsening Mechanisms in Surface-doped Nanoporous Metals: Jesse Ko1; Ian Mccue2; Zhiyong Xia1; 1Johns Hopkins University Applied Physics Laboratory; 2Northwestern University
Due to their high surface-to-volume ratios, nanostructured catalysts offer benefits in electrochemical energy storage and conversion technologies. However, these materials have intrinsically metastable morphologies and degrade via coarsening during service. One potential mitigation strategy is to introduce impurities on the catalyst surface that inhibit diffusional transport. While there have been instances of utilizing this strategy to successfully improve catalyst stability, there is no guiding principle regarding what fraction of impurities are required. In order to answer this question, we investigated the impact of trace surface dopants on coarsening in a representative nanostructured catalyst material: nanoporous platinum. Through a combination of experimental and computational metrics, we determined how the coarsening rate and surface site density was impacted by trace (2-8%) Ir impurities. Insights from this work will have a measurable impact on the effort to bridge the gap between highly active and highly stable catalyst materials.
10:20 AM Invited
High Energy and Power Density Batteries Enabled by Electrodeposition and Self-assembly: Paul Braun1; 1University of Illinois
Conventional Li-ion batteries are formed using slurry-cast electrodes whose random nature limits both energy density and rate performance, and is generally incompatible with solid-state designs. We have made considerable strides in electrodeposition of electrode materials in both solid and deterministically mesostructured form with enhanced energy densities and rate performances. I will present our work on the electrodeposition of high performance silicon and tin-based Na and Li-ion anodes and LiCoO2, NaCoO2, LiMn2O4, and Al-doped LiCoO2-based Na and Li-ion cathodes. The electrolytically active materials were formed either as solid films, or where significant volume changes upon cycling are present, as a 3D mesostructured film. The capacities are near-theoretical, and in the case of the electroplated oxides, the crystallinities and electrochemical capacities are comparable, or in some cases, even better than powders synthesized at much higher temperatures. Finally, I will discuss our first strides to build solid-state batteries using these electrodes.
10:50 AM Invited
Nanoporous Gold: From an Ancient Material to Biomedical Devices: Erkin Seker1; 1University of California, Davis
Nanoporous gold (np-Au), produced by a nano-scale self-arrangement process, has mostly attracted attention for catalyst applications due to its high effective surface area, electrical conductivity, and ease of surface functionalization. Surprisingly, biomedical potential of this material has remained largely untapped. I will initially discuss my research group’s efforts to control nano-/micro-scale properties of np-Au and the application of micropatterning techniques for fabricating multiple electrode arrays for high-fidelity neural electrophysiological recordings. In the context of biocompatibility of such devices, I will illustrate how tunable properties of np-Au may be utilized to alleviate adverse biological response to device coatings. To that end, I will specifically focus on np-Au’s drug delivery performance and its interaction with neural tissue as a function of its geometric features and surface chemistry. I will finally illustrate np-Au’s diagnostic potential within an electrochemical platform in detecting and purifying nucleic acid biomarkers in complex biological samples.
11:20 AM
Elasto-plastic NiTi Nanofoams for Potential Elastocaloric Cooling Applications Using Molecular Dynamics: Arne Klomp1; Karsten Albe1; 1TU Darmstadt
The prototypical shape memory alloy NiTi exhibits a remarkable elastocaloric response during its martensitic transition and can be employed in solid-state cooling devices. Fast heat transfer from NiTi to the environment can be enabled by a high surface-to-volume ratio. Open porosity NiTi (nanofoam) might be promising for this purpose. We use molecular dynamics simulations to investigate NiTi phase transitions under cyclic thermal and mechanical loading in nanowires and nanofoams. The thermo-mechanical properties of the nanofoam featuring locally changing surface orientation, length scales, and curvature lead to a smooth martensitic transition. The ability of NiTi to accommodate large inelastic strains receives special attention and we show that there is a lower size limit for a reversible martensitic phase transition. Using atomistic simulation we are also able to monitor the caloric effects of NiTi, thus, opening opportunities for evaluating NiTi in conditions close to its potential application.