A5039029548- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Machine Learning in Materials Science
- Electron and X-Ray Spectroscopy Techniques
- Advanced Battery Technologies Research
- Advanced Electron Microscopy Techniques and Applications
- Inorganic Chemistry and Materials
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- High-pressure geophysics and materials
- Non-Destructive Testing Techniques
- Crystallography and molecular interactions
- Electrochemical sensors and biosensors
- Magnetic and transport properties of perovskites and related materials
- Force Microscopy Techniques and Applications
- Multiferroics and related materials
- Electrochemical Analysis and Applications
- Radiation Shielding Materials Analysis
- Advanced X-ray Imaging Techniques
- Crystallography and Radiation Phenomena
- Analytical Chemistry and Sensors
- Thermal Expansion and Ionic Conductivity
- nanoparticles nucleation surface interactions
- Theoretical and Computational Physics
- Luminescence Properties of Advanced Materials
Stanford University
2019-2025
SLAC National Accelerator Laboratory
2024-2025
Materials Science & Engineering
2020-2024
X-ray spectroscopy has been a key method to determine ground- and excited-state properties of quantum materials with atomic specificity. Now, new x-ray facilities are opening the door study pump-probe spectroscopy—specifically, time-resolved absorption (trXAS) resonant inelastic scattering (trRIXS). In this paper, we will present simulations each these spectroscopies using time-domain full multiplet, charge-transfer Hamiltonian adapted generalized cluster model including central...
Recent studies of La_{3}Ni_{2}O_{7} have identified a bilayer (2222) structure and an unexpected alternating monolayer-trilayer (1313) structure, both which feature signatures superconductivity near 80 K under high pressures. Using angle-resolved photoemission spectroscopy, we measure the electronic 1313 samples. In contrast to previously studied 2222 find that hosts flat band with markedly different binding energy, as well additional electron pocket splittings. By comparison local-density...
Abstract The solid electrolyte interphase (SEI) has been identified as a key challenge for Li metal anodes. brittle and inhomogeneous native SEI generated by parasitic reactions between liquid electrolytes can devastate battery performance; therefore, artificial SEIs (ASEIs) have proposed an effective strategy to replace SEIs. Herein, collaboration academia industrial R&D teams, multifunctional (crystalline, high modulus, robust, + ion conductive, electrolyte‐blocking, solution...
py4DSTEM is a free, open source, python-based data analysis package for the emerging field of fourdimensional scanning transmission electron microscopy (4D-STEM).In 4D-STEM, beam rastered across sample and diffraction pattern collected at each scan position, yielding highly information-rich datasets which can be used to virtually recreate images that map orientation, local lattice parameters, strain, short/medium range ordering, or reconstruct electrostatic potential itself [1].These easily...
We introduce an adhesion parameter that enables rapid screening for materials interfaces with high adhesion. This is obtained by density functional theory calculations of individual single-material slabs rather than consisting combinations two materials, eliminating the need to calculate all configurations a prohibitively vast space possible interface configurations. Cleavage energy are used as upper bound electrolyte and coating energies implemented in adapted contact angle equation derive...
Signatures of superconductivity near 80 K were recently discovered in crystals La-Ni-O with the stoichiometry 3:2:7 under high pressures. Structural studies have shown conflicting results highlighting both expected bilayer (2222) structure and an unexpected alternating monolayer-trilayer (1313) structure, apparently showing superconductivity. Here, we perform angle-resolved photoemission spectroscopy on 1313 to elucidate distinct electronic features compared previously studied 2222...
In this work, we build a computationally inexpensive, data-driven model that utilizes only atomistic structure information to predict the reactivity of interfaces between any candidate solid-state electrolyte material and Li metal anode. This is trained on data from ab initio molecular dynamics (AIMD) simulations time evolution solid electrolyte-Li interface for 67 different materials. Predicting state with techniques remains an elusive challenge in materials discovery informatics, previous...
Iron is the most abundant transition metal in Earth’s crust, and redox cycling between its well-known low-valent oxidation states of FeII FeIII drives crucial processes nature. The FeII/III couple charge compensates lithium iron phosphate, a positive electrode (cathode) for lithium-ion batteries. High-valent couples, involving formal higher than FeIII, could deliver electrochemical potentials energy densities. However, because instability high-valent Fe electrodes, they have proven difficult...
Lithium iron phosphate (LixFePO4), a cathode material used in rechargeable Li-ion batteries, phase separates upon de/lithiation under equilibrium. The interfacial structure and chemistry within these materials affects transport, therefore battery performance. Correlative imaging of LixFePO4 was performed using four-dimensional scanning transmission electron microscopy (4D-STEM), X-ray (STXM), ptychography order to analyze the local same particle set. Over 50,000 diffraction patterns from 10...
X-ray spectroscopy has been a key method to determine ground and excited state properties of quantum materials with atomic specificity. Now, new x-ray facilities are opening the door study pump-probe - specifically time-resolved absorption (trXAS) resonant inelastic scattering (trRIXS). In this paper we will present simulations each these spectroscopies using time-domain full multiplet, charge transfer Hamiltonian, adapted generalized cluster model including central transition metal ion...
The overwhelming majority of layered oxide cathode materials are based on the redox activity expensive and scarce transition metals like Co Ni. While Fe-redox material LiFePO 4 has become increasingly attractive due to its low cost, gravimetric energy density relatively operating voltage limit use cases. A high-voltage Fe-based would provide high utilizing redox-activity most abundant metal in Earth’s crust, but such a that provides stable reversible electrochemical performance remains...
In this work, we build a computationally inexpensive, data-driven model that utilizes atomistic structure information to predict the reactivity of interfaces between any candidate solid-state electrolyte material and Li metal anode. This is trained on data from
The layered cobaltate CaCoO$_2$ exhibits a unique herringbone-like structure. Serving as potential prototype for new class of complex lattice patterns, we study the properties using X-ray absorption spectroscopy (XAS) and resonant inelastic scattering (RIXS). Our results reveal significant inter-plane hybridization between Ca $4s-$ Co $3d-$orbitals, leading to an inversion textbook orbital occupation square planar geometry. Further, our RIXS data strong low energy mode, with anomalous...
As demand for better performance in energy storage increases, a clear understanding of the charge compensating mechanism Li-ion battery cathodes is essential developing next generation chemistries and materials. X-ray core level spectroscopies, e.g. x-ray absorption spectroscopy (XAS) resonant inelastic scattering (RIXS), allow experimental measurement electronic structure materials before after charge, providing clearest physical picture electrochemical device operation. Here, we present...
Anionic redox is defined as the depopulation of electronic states consisting unhybridized or minimally hybridized O 2 p orbitals. In recent years, anionic has been investigated in great detail due its potential to increase high-voltage capacity Na-ion and Li-ion intercalation positive electrodes (cathodes) for batteries. However, almost always manifests alongside a gamut undesirable effects, from > 1 V hysteresis, voltage fade over hundreds cycles. These effects have hindered widespread...
Journal Article Relationship between mechanical strain and chemical composition in LiFePO4 via 4D-scanning transmission electron microscopy scanning X-ray Get access LA Hughes, Hughes National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley Laboratory, Berkeley, CA 94708, USA Corresponding author, laurenhughes@lbl.gov Search other works by this author on: Oxford Academic Google Scholar Benjamin H Savitzky, Savitzky Haitao D Deng, Deng Depart. of Mat. Sci. & Eng.,...
Lithium iron phosphate (LixFePO4), a cathode material used in rechargeable Li-ion batteries, phase separates upon de/lithiation under equilibrium. The interfacial structure and chemistry within these materials affects transport, therefore battery performance. Correlative imaging of LixFePO4 was performed using four-dimensional scanning transmission electron microscopy (4D-STEM), X-ray (STXM), ptychography order to analyze the local same particle set. Over 50,000 diffraction patterns from 10...
We introduce an adhesion parameter that enables rapid screening for materials interfaces with high adhesion. This is obtained by density functional theory calculations of individual single-material slabs rather than consisting combinations two materials, eliminating the need to calculate all configurations a prohibitively vast space possible interface configurations. Cleavage energy are used as upper bound electrolyte and coating energies implemented in adapted contact angle equation derive...
Solid state phase transformation triggered by lithium insertion is ubiquitous in many commercially available battery electrodes such as LiXFePO4 (LFP), LiXCoO2 and graphite. Understanding the kinetics of transformation, particular nucleation growth a second due to Li compositional changes key achieving high cycling rates these separating materials. LFP model transforming material with large miscibility gap that thermodynamically favors separation (segregation into Li-rich Li-poor phases)...