Bulletin of the American Physical Society
APS March Meeting 2019
Volume 64, Number 2
Monday–Friday, March 4–8, 2019; Boston, Massachusetts
Session C47: Electrochemical Interfaces |
Hide Abstracts |
Sponsoring Units: GERA Chair: Carlos Gutierrez, Sandia Natl Labs Room: BCEC 213 |
Monday, March 4, 2019 2:30PM - 2:42PM |
C47.00001: Lithium Electroreduction at Metal/Polymer Interfaces for Lithium Metal Batteries via Atomistic Molecular Dynamics Simulation Jeongmin Kim, Thomas Miller Understanding and stabilizing lithium electrodeposition is a major bottleneck for developing safe and cyclable lithium metal batteries. The process is complicated by the heterogeneous composition and structure of the solid electrolyte interphase (SEI). To establish a molecular understanding of lithium electroreduction, we employ atomistic molecular dynamics simulations to address ion solvation properties and electron-transfer kinetics of electrochemical reactions at a model SEI/metal interface. Our SEI model is a chemically and structurally well-defined homopolymer including poly (ethylene oxide) (PEO) and poly (ethylene carbonate) (PEC). Model electrodes are either pristine or structurally inhomogeneous with pre-existing deposits. Both the electrodes and deposited lithium are modeled using time-dependent induced-charge polarizability. In this talk, we discuss the effects of the SEI and surface-roughness on the kinetics and mechanism of interfacial lithium electroreduction. |
Monday, March 4, 2019 2:42PM - 2:54PM |
C47.00002: Ab Initio Molecular Dynamics Study of the Effect of Lithium Salts on Lithium Superoxide Clustering in Lithium-Air Batteries Emily Crabb, Arthur France-Lanord, Graham Michael Leverick, Yang Shao-Horn, Jeffrey C Grossman Lithium-air batteries are an active area of research because of their potential to have a much higher energy density than traditional lithium-ion batteries. However, they are not yet commercially viable due to poor efficiency, high charging voltages, and low cycle lifetimes. Experimental studies of Li-air batteries with aprotic solvents have shown that the O2 reduction starts when superoxide (O2-) forms in solvent and reacts with Li+ to form lithium superoxide (Li+-O2-). Solid Li2O2 then forms as the final discharge product on the cathode. Recent experimental work has suggested that a better understanding of the factors governing the behavior of the lithium superoxide in solvent could help control the discharge at the cathode. We are therefore modeling systems of lithium salts and LiO2 molecules in various common solvents such as dimethyl sulfoxide, acetonitrile, and 1,2-dimethoxyethane to examine how the interplay between solvents and salts affects properties such as LiO2 clustering behavior. Results from these explicit solvent calculations performed using density functional theory calculations and ab-initio molecular dynamics simulations will be presented and discussed. |
Monday, March 4, 2019 2:54PM - 3:06PM |
C47.00003: Operando soft x-ray spectroscopy characterization of interfacial charge transfer in energy materials and catalysis Jinghua Guo, Yi-Sheng Liu Soft x-ray spectroscopic techniques with operando capabilities offer the unique characterization in energy conversion/storage materials and catalysis in regards to the functionality, complexity, and interactions among constituents within. It has been found that the microstructure and composition of materials as well as the evolution process have a great influence on performances in a variety of fields, e.g., energy conversion and energy storage materials, chemical and catalytic processes. Operando soft x-ray characterization offers an opportunity to uncover the phase conversion, chemical environment change of elements and other very important information of solid/gas and solid/liquid interfaces in real time. We will overview a number of the experimental studies that successfully revealed the catalytic and electrochemical reactions in real time, e.g. solid (Au or hematite films)/liquid (water) electrochemical interface, Mg-ion batteries, and Li-S batteries. The experimental results demonstrate that the operando soft x-ray characterization provides the unique information for understanding the real reaction mechanism. |
Monday, March 4, 2019 3:06PM - 3:18PM |
C47.00004: Probing Multiscale Ion Transport and Heterogeneties in High Capacity Battery Materials : From Meso to Micronscale Jagjit Nanda Majority of electrode materials used for advanced lithium based batteries have well defined chemical composition and particle morphology. The chemistry as well as the microstructure can undergo reversible or irreversible changes under continuous electrochemical charge-discharge cycles. These could have measurable impact on the battery capacity and life. The talk will cover the recent work related to applying x-ray transmission imaging combined with near edge absorption spectroscopy (XANES) to study the evolution of chemical oxidation state of the transition metal (TM) cations accompanied by changes in the particle morphology for lithium-manganese rich NMC cathodes (LMR-NMC). 2D XANES images collected for LMR-NMC cathodes at various stages of cycling (4.8-2.5V) can be reconstructed in 3D to measure bulk changes in TM concentration as well as monitor the change in morphology. The later part of the talk will highlight the various multiscale Raman imaging methods for studying electrode-electrolyte interfaces. |
Monday, March 4, 2019 3:18PM - 3:30PM |
C47.00005: Mapping the Atomistic Structure of the Electrical Double Layer with X-ray Reflectivity and Molecular Dynamics Katherine Harmon, Felipe Jimenez-Angeles, Sang Soo Lee, Michael J Bedzyk, Monica Olvera de la Cruz, Paul Fenter A driving factor in electrochemical energy storage is the adsorption of ions in an electrical double layer (EDL) at the electrode-electrolyte interface. A complete understanding of the structure-property relationships among charged surfaces, ions, and solvents that give rise to the EDL is needed to optimize capacitive energy storage devices. Here, we present in situ X-ray reflectivity (XR) and resonant anomalous XR (RAXR) results of the atomistic, element-specific structure of the EDL at the interface of a graphene/SiC electrode and aqueous RbCl. RAXR data are analyzed using increasingly complex levels of theory of the EDL structure, starting from the simple Gouy-Chapman model of an exponentially decaying charge distribution, to assess the level of theory needed to describe the data. Classical MD simulations of the system qualitatively agree with the experimental structures. A quantitative analysis of the MD predictions is performed via direct comparison of the experimental data with RAXR signals expected from the predicted structures. |
Monday, March 4, 2019 3:30PM - 3:42PM |
C47.00006: Li charge transfer simulation at graphite/solution interface using density functional calculation combined with implicit solvation model Jun Haruyama, Tamio Ikeshoji, Minoru Otani Because charge transfer reactions at electrode/solution interfaces limits the performance of lithium-ion batteries (LIBs), it is considered that Li insertion/desorption reaction at the interface between graphite anode and electrolyte solution. Density functional theory + effective screening medium (ESM) method combined with reference interaction site model (RISM), ESM-RISM [1], is applicable to the charge transfer reaction because the chemical potential of electrons (µe) corresponds to an electrode potential [2] and the distribution function of the solvation is automatically formulated for the solvation/desolvation structures. The reacting Li is moved from the stable site in graphite to the bulk solution region. The constant-µe ESM-RISM simulations show that the assuming Li path is accompanied by an electron transfer process. The activation energy at equilibrium potential is approximately 0.6 eV[3], which is consistent with experiments. The dependences of the activation energy and the surface charge density according to the Li content x (LixC6, x=0, 0.5, 1) are further discussed. [1] S. Nishihara and M. Otani, PRB 96, 115429 (2017). [2] J. Haruyama, T. Ikeshoji, and M. Otani, PRM 2, 095801 (2018). [3] J. Haruyama, T. Ikeshoji, and M. Otani, J. Phys. Chem. C 122, 9804 (2018). |
Monday, March 4, 2019 3:42PM - 3:54PM |
C47.00007: Study of Charge Transport Kinetics and Diffusion at Hybrid Perovskite- Liquid Electrolyte Interface by Electrochemical Impedance Spectroscopy Priya Srivastava, Monojit Bag A lot of research has been done on the efficiency improvement of Perovskite Solar Cells by optimization of the film morphology using various techniques including electrochemical impedance spectroscopy (EIS) in a solid-state active device geometry.1 Recently, the optimization of the film morphology at liquid electrolyte interface by EIS is trending as a more simplified and accurate approach. 2,3 |
Monday, March 4, 2019 3:54PM - 4:06PM |
C47.00008: Elucidating Electrodeposition Instability at the Solid-solid Interface Aashutosh Mistry, Partha P Mukherjee Metallic anodes could potentially alter the future of energy storage; however, their irregular electrodeposition has been a long-standing concern. It is often argued that the solid electrolytes should lead to uniform deposition since additional strain energy has to be spent in growing an irregular deposit. In other words, the mechanical rigidity of the solid electrolytes should foster stable deposition. Despite this intuitive argument, often irregular deposition takes place at higher currents, even if the electrolyte has enough mechanical stiffness. |
Monday, March 4, 2019 4:06PM - 4:18PM |
C47.00009: Time Evolution of Li-ion Battery Electrode Passivation Layer Modification by Synchrotron Radiation Benjamin Young, David R. Heskett, Joseph Woicik, Brett L Lucht Surface sensitivity available to photoelectron spectroscopies (PES) makes them popular techniques for characterization of chemical environments at shallower depths than other, more bulk-sensitive techniques, and PES measurements are generally thought to be non-destructive. Variable energy, synchrotron radiation (SR) permits access to information not available to common lab-based radiation sources, making high-energy PES studies extremely useful for understanding thin films and interfaces. High SR flux has been useful for developing models of soft x-ray induced effects, but hard x-ray SR-induced effects are less well studied and will be increasingly important as popularity and availability of SR for thin film analysis continues to grow. We report on observed modification of the solid electrolyte interphase of a lithium-ion battery electrode during prolonged exposure to 4 keV SR. The effects can be summarized by desorption of oxygen-containing species from the sample surface and by reactions within the film. Also presented is an estimate of the layer thickness’ time evolution during prolonged SR exposure. |
Monday, March 4, 2019 4:18PM - 4:30PM |
C47.00010: Decomposition of phosphorus-containing additives at a charged NMC surface: atomistic modeling insights Hakim Iddir, Juan Garcia, Adam Tornheim, Ritu Sahore, Ira Bloom, Zhengcheng Zhang Stabilizing the cathode/electrolyte interface at high voltage is necessary to achieve higher capacities while still maintaining capacity retention in Lithium-ion batteries. One strategy is through the use of additives in the electrolyte: components in low concentration (<10%) that have a lower anodic stability than the baseline electrolyte, so that during the initial cycles, the additive will decompose on the charged cathode surface preferentially over the baseline electrolyte. This reaction will then yield a layer which will inhibit further reaction between the electrolyte and the cathode surface. However, the mechanism of improvement remains unclear. In the present work, Density Functional Theory is used to gain insights and understanding on experimental results using a potentiostatic hold technique to evaluate cathode/electrolyte reactivity for two families of additives: phosphites and phosphates. Simulations indicate the susceptibility of the various additives to electrochemical and chemical oxidation, showing chemical oxidation to be much more likely with the phosphite moiety. The identity of the ligands on the phosphorus-containing additive can dramatically affect both the decomposition current and the cathode surface film. |
Monday, March 4, 2019 4:30PM - 4:42PM |
C47.00011: Characterization of Electrical Energy Storage Interfaces with Advanced Optical, Electrochemical, and X-ray Probes Jonathan Larson, Hans Bechtel, Ethan J Crumlin, Robert Kostecki Novel and improved methods for energy storage are urgently required to enable effective use of renewable energy sources and to facilitate energy demand-response management across time and length scales. While lithium-ion batteries meet many of the criteria required for portable electronics, they are insufficient to meet the requirements for emerging applications (e.g. aerospace) and grid scale storage. New electrical energy storage concepts are needed to meet these current and future demands. Central to the onset of transformational breakthroughs is the need to increase understanding of the fundamental physical and chemical processes that occur in these complex systems. To this end, we plan to impact this space by leveraging synchrotron-enabled scanning broadband nanoscopy and nano-FTIR spectroscopy for local information on permittivity and chemistry, scanning nanobattery probes for local nano-electrochemical testing, and ambient pressure X-ray photoelectron spectroscopy. Here we provide an operational overview, and the advantages of, these cutting-edge characterization techniques for advancing the basic science of electrical energy storage interfaces. |
Monday, March 4, 2019 4:42PM - 4:54PM |
C47.00012: Thermodynamic and Mechanical Stability of Crystalline Phases of Li2S2 Qing Guo, Kah Chun Lau, Ravindra Pandey
|
Monday, March 4, 2019 4:54PM - 5:06PM |
C47.00013: Computational Development of an Artificial Solid Electrolyte Interphase for Rechargeable Multivalent Ion Batteries Joshua Young, Manuel Smeu Multivalent ion batteries (MVIB), or those utilizing Mg, Ca, Zn, and Al, are garnering increasing attention as alternatives to Li-ion batteries in non-portable applications such as grid storage, as they are energy dense, cost efficient, and safe. The development of such MVIBs, however, has been hindered by the inability of existing electrolytes to reversibly plate and strip metallic anodes. This is a particular problem in Ca ion batteries, as the the solid-electrolyte interphase (SEI, the passivating layer which forms between the electrolyte and anode) does not allow for the migration of Ca2+ ions. In this work, we develop an understanding of this SEI using a computational approach combining DFT and ab initio molecular dynamics (AIMD) simulations. First, we show that AIMD can be utilized to predict the decomposition products making up the SEI in a variety of systems containing different anodes and electrolytes. Second, we demonstrate that the use of an amorphous Al2O3 layer between the Ca metal anode and organic electrolyte prevents decomposition while allowing for the transport of Ca ions. We propose that this strategy can aid in the development of rechargeable Ca ion batteries by completely avoiding the formation of an ionically insulating SEI from electrolyte decomposition. |
Monday, March 4, 2019 5:06PM - 5:18PM |
C47.00014: Predicting pseudocapacitive adsorption isotherms through quantum-continuum calculations NATHAN KEILBART, Yasuaki Okada, Shinichi Higai, Ismaila Dabo Pseudocapacitive electrodes function through redox reactions that occur on the surface of the electrode allowing for high charging/discharging rates. Complex interfaces cause much to be unknown about the pseudocapacitive process. Computational modeling has made progress in predicting the response of these systems but further research is needed to optimize performance. A theoretical approach is developed to study pseudocapacitive systems, focusing on ruthenium dioxide (RuO2). Material properties from quantum-continuum simulations are combined with Monte Carlo sampling to predict adsorption isotherms. Computational findings for the RuO2 (110) surface show good agreement with experimental data where the double-layer contribution is shown to be a small fraction of the overall electrochemical response but controls to a the overall pseudocapacitive response of the electrode. By focusing on the double-layer contribution, different trends emerge based on the surface orientation. For RuO2 (110), the double-layer capacitance from electronic-structure methods show a small spread while a downward trend is seen for (100) with increasing coverage. By using double-layer capacitance predicted from first principles, good agreement is reached with experiment along the (100) surface orientation. |
Monday, March 4, 2019 5:18PM - 5:30PM |
C47.00015: Decoding the surface instability of perovskite oxides at the atomic level: Sr segregation in La1-xSrxMnO3±δ in SOFC electrodes Franziska Hess, Bilge Yildiz One of the most important and best-studied perovskite materials for energy conversion applications is La1-xSrxMnO3 (LSM). As the oxygen exchange at the surface is typically rate-limiting, tuning of the electrode surface is a key aspect in the development and optimization of materials for energy conversion applications. Sr-doped perovskite materials form passivating Sr-rich layers which inhibit the oxygen exchange at the surface, thus reducing the efficiency of the SOFC. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700