Odom Lecture: Chemo-mechanics in all solid state batteries

mnlo230 — Fri, 20 Sep 2024 17:28:12 +0000

Odom Lecture: Chemo-mechanics in all solid state batteries mnlo230 Fri, 09/20/2024 - 01:28 pm

Abstract: Li-free solid-state batteries, which contain no excess Li metal initially, are considered promising next-generation energy storage systems due to their high energy density and enhanced safety. However, heterogeneous Li plating onto the current collector leads to early failure and low energy efficiency. Porous interlayers positioned between the current collector and solid electrolyte have the potential to guide uniform Li plating and improve electrochemical performance. In this configuration, both the electrochemical reduction of Li ions and mechanical deformation, which allow Li metal to flow into the porous interlayer, occur simultaneously. These complexities make understanding Li plating kinetics challenging. Factors such as stack pressure, interlayer composition, current density, and the mechanical response of the interlayer can influence Li deposition kinetics. In this talk we discuss how heterogenous plating can cause fracture in the cathode and impacts the reversible operation of li-free solid state batters. We examine a model porous Ag-C interlayer with two different Ag particle sizes and observed Li plating behavior under various stack pressures and current densities. While Ag nanoparticles in the interlayer can facilitate Li movement, they can also induce internal stress, leading to void formation that impedes Li flow. Nanostructure analysis using cryo-FIB are combined with chemomechanical modeling to uncover the mechanical interaction of interlayer during the alloying reaction between Ag and Li. When comparing the morphology of Li electrodeposits at different conditions, morphological changes correlate with the creep strain rate over Li ion flux. The electrochemical performance is determined by the morphology of Li electrodeposits rather than the Li plating current density.

Bio: Dr. Hatzell is an Associate Professor at Princeton University in the Andlinger Center for Energy and Environment and department of Mechanical and Aerospace Engineering. Dr. Hatzell earned her Ph.D. in Material Science and Engineering at Drexel University, her M.S. in Mechanical Engineering from Pennsylvania State University, and her B.S./B.A. in Engineering/Economics from Swarthmore College. Hatzell is the recipient of several awards including the ORAU Powe Junior Faculty Award (2017), NSF CAREER Award (2019), ECS Toyota Young Investigator Award (2019), finalist for the BASF/Volkswagen Science in Electrochemistry Award (2019), the Nelson “Buck” Robinson award from MRS (2019), Sloan Fellowship in ��vlog�ٷ�� (2020), and POLiS Award of Excellence for Female Researchers (2021), NASA Early Career Award (2022), ONR Young investigator award (2023) and Camille-Dreyfus Teacher-Scholar Award (2024).

The Hatzell Research Group works on understanding phenomena at solid|liquid, solid|gas, and solid|solid interfaces through non-equilibrium x-ray techniques, with particular interest in energy conversion and storage and separations applications.

Date:

Friday, November 1, 2024 - 04:15 pm

Location:

JSB 121

Event Series:

��vlog�ٷ�� Department Seminar

Lecture

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Dawson Lecture: Purely Organic Emitters for Organic Light-Emitting Diodes (OLEDs): A Journey through Organic Electronics

mnlo230 — Fri, 20 Sep 2024 14:35:22 +0000

Dawson Lecture: Purely Organic Emitters for Organic Light-Emitting Diodes (OLEDs): A Journey through Organic Electronics mnlo230 Fri, 09/20/2024 - 10:35 am

Abstract: After an introduction to organic light-emitting diodes, we will discuss our recent computational work dealing with three strategies to design efficient, purely organic emitters:

The first strategy was introduced in 2012 by Chihaya Adachi and co-workers at Kyushu University, who proposed to harvest the triplet excitons in purely organic molecular materials via thermally activated delayed fluorescence (TADF). These materials now represent the third generation of OLED emitters. Impressive photo-physical properties and device performances have been reported, with internal quantum efficiencies reaching 100% (which means that, for each injected electron, one photon is emitted). In the most efficient materials, the TADF process has been shown to involve several singlet and triplet excited states.

A second strategy, which has been applied more recently, was proposed by Feng Li and co-workers at Jilin University in 2015 and is based on the exploitation of stable organic radicals. In these materials, where the lowest excited state and the ground state usually belong both to the doublet manifold, we will describe how high efficiencies and photo-stability can be obtained.

Finally, we will briefly discuss our very recent work on so-called multi-resonance (MR) TADF materials, initially developed by Takuji Hatakeyama and co-workers at Kwansei Gakuin University.

Bio: Jean-Luc Brédas received his B.Sc. (1976) and Ph.D. (1979) degrees from the University of Namur, Belgium. In 1988, he was appointed Professor at the University of Mons, Belgium, where he established the Laboratory for ��vlog�ٷ�� of Novel Materials. While keeping an “Extraordinary Professorship” appointment in Mons, he joined the University of Arizona in 1999. In 2003, he moved to the Georgia Institute of Technology where he became Regents’ Professor of ��vlog�ٷ�� and Biochemistry and held the Vasser-Woolley and Georgia Research Alliance Chair in Molecular Design. Between 2014 and 2016, he joined King Abdullah University of Science and Technology (KAUST) as a Distinguished Professor and served as Director of the KAUST Solar & Photovoltaics Engineering Research Center. He returned to Georgia Tech in 2017 before moving back to the University of Arizona in 2020. Prof. Brédas is an elected Member of the International Academy of Quantum Molecular Science, the Royal Academy of Belgium, and the European Academy of Sciences. He is the recipient of the 1997 Francqui Prize, the 2000 Quinquennial Prize of the Belgian National Science Foundation, the 2001 Italgas Prize, the 2003 Descartes Prize of the European Union, the 2010 ACS Charles Stone Award, the 2013 APS David Adler Award in Materials Physics, the 2016 ACS Award in the ��vlog�ٷ�� of Materials, the 2019 Alexander von Humboldt Research Award, the 2020 MRS Materials Theory Award, and the 2021 RSC Centenary Prize. He has served as editor for ��vlog�ٷ�� of Materials between 2008 and 2021 and scientific editor for Materials Horizons since 2022. His current Google Scholar h-index is 171.

To view this years brochure, click here.

Date:

Friday, October 25, 2024 - 04:00 pm

Location:

CP 155

Event Series:

Lecture

��vlog�ٷ�� Department Seminar

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