Lecture / en Odom Lecture: Chemo-mechanics in all solid state batteries /odom-lecture <span>Odom Lecture: Chemo-mechanics in all solid state batteries</span> <span><a title="View user profile." href="/users/mnlo230">mnlo230</a></span> <span><time datetime="2024-09-20T13:28:12-04:00" title="Friday, September 20, 2024 - 01:28 pm">Fri, 09/20/2024 - 01:28 pm</time> </span> <div><p><strong>Abstract: </strong>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.&nbsp;</p> <p><strong><img src="/sites/default/files/inline-images/Hatzell_headshot_andlinger.jpg" data-entity-uuid="8459fd91-aa2e-4884-8181-a04d5f790fb8" data-entity-type="file" width="175" height="233" class="align-left" loading="lazy">Bio:</strong> 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 vlogٷ (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).&nbsp;</p> <p>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.&nbsp;</p> </div> <div> <div class="field-label font-bold inline-block">Date: </div> <div class="field-items inline-block"> <div><time datetime="2024-11-01T20:15:00Z">Friday, November 1, 2024 - 04:15 pm</time> </div> </div> </div> <div> <div class="field-label font-bold inline-block">Location: </div> <div class="inline-block">JSB 121</div> </div> <div> <div class="field-label font-bold inline-block">Event Series: </div> <div class="field-items inline-block"> <div><a href="/event-type/chemistry-department-seminar" hreflang="en">vlogٷ Department Seminar</a></div> <div><a href="/event-type/lecture" hreflang="en">Lecture</a></div> </div> </div> <ul class="links inline"><li><a href="/odom-lecture" rel="tag" title="Odom Lecture: Chemo-mechanics in all solid state batteries" hreflang="en">Read more<span class="visually-hidden"> about Odom Lecture: Chemo-mechanics in all solid state batteries</span></a></li></ul> Fri, 20 Sep 2024 17:28:12 +0000 mnlo230 1066291 at Dawson Lecture: Purely Organic Emitters for Organic Light-Emitting Diodes (OLEDs): A Journey through Organic Electronics /27th-annual-dawson-lecture-purely-organic-emitters-organic-light-emitting-diodes-oleds-journey <span>Dawson Lecture: Purely Organic Emitters for Organic Light-Emitting Diodes (OLEDs): A Journey through Organic Electronics</span> <span><a title="View user profile." href="/users/mnlo230">mnlo230</a></span> <span><time datetime="2024-09-20T10:35:22-04:00" title="Friday, September 20, 2024 - 10:35 am">Fri, 09/20/2024 - 10:35 am</time> </span> <div><p><strong>Abstract:</strong> 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:&nbsp;</p> <p>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.&nbsp;</p> <p>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.&nbsp;</p> <p>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.</p> <p><img src="/sites/default/files/inline-images/Screenshot%202024-09-06%20161113.png" data-entity-uuid="427809cf-6ff0-4749-b3fe-fde1a643ad3b" data-entity-type="file" width="697" height="193" loading="lazy"> </p><p><strong><img src="/sites/default/files/inline-images/Bredas%20-%20Headshot_0.jpg" data-entity-uuid="e691aabd-4efd-4f7b-9915-cce94b4269bb" data-entity-type="file" width="186" height="2