A5044666831- Advancements in Battery Materials
- Electron and X-Ray Spectroscopy Techniques
- Advanced Battery Materials and Technologies
- Advanced Electron Microscopy Techniques and Applications
- Advanced Battery Technologies Research
- Anodic Oxide Films and Nanostructures
- Advanced Materials Characterization Techniques
- Electrochemical Analysis and Applications
- Force Microscopy Techniques and Applications
- Semiconductor materials and devices
- Nanowire Synthesis and Applications
- Ion-surface interactions and analysis
- Quantum Dots Synthesis And Properties
- Corrosion Behavior and Inhibition
- Semiconductor materials and interfaces
- Supercapacitor Materials and Fabrication
- Semiconductor Quantum Structures and Devices
- Conducting polymers and applications
- Graphene research and applications
- Extraction and Separation Processes
- Molecular Junctions and Nanostructures
- Electronic and Structural Properties of Oxides
- Hydrogen embrittlement and corrosion behaviors in metals
- Carbon Nanotubes in Composites
- Electrocatalysts for Energy Conversion
National Renewable Energy Laboratory
2022-2025
Sandia National Laboratories
2015-2024
Center for Integrated Nanotechnologies
2014-2023
Sandia National Laboratories California
2014-2022
Los Alamos National Laboratory
2020
University of California, Los Angeles
2020
Brookhaven National Laboratory
2013-2014
University of Maryland, College Park
2014
University of California, Davis
2010-2012
Direct visualization of lead sulfide nanoparticle growth is demonstrated by selectively decomposing a chemical precursor from multicomponent solution using in situ liquid transmission electron microscopy. We demonstrate reproducible control over mechanisms that dictate the final morphology nanostructures while observing real-time with subnanometer spatial resolution. Furthermore, an intense beam can initiate growth, it also shown laser trigger reaction independently imaging electrons.
Carbonaceous materials have great potential for applications as anodes of alkali-metal ion batteries, such Na-ion batteries and K-ion (NIB KIBs). We conduct an in situ study the electrochemically driven sodiation potassiation individual carbon nanofibers (CNFs) by transmission electron microscopy (TEM). The CNFs are hollow consist a bilayer wall with outer layer disordered-carbon (d-C) enclosing inner crystalline-carbon (c-C). d-C exhibits about three times volume expansion c-C after full or...
We offer an explanation for how dendrite growth can be inhibited when Li metal pouch cells are subjected to external loads, even using soft, thin separators. develop a contact mechanics model tracking surface and sub-surface stresses where electrodes have realistically (micron-scale) rough surfaces. Existing models examine single, micron-scale protrusion under fixed local current density that presses more or less conformally against separator stiff electrolyte. At the larger, sub-mm scales...
Using in situ liquid cell electron microscopy we investigate Pd growth dilute aqueous salt solutions containing Au nanoparticle seeds. Au-Pd core-shell nanostructures are formed via deposition of Pd(0), generated by the reduction chloropalladate complexes radicals, such as hydrated electrons (eaq(-)) induced beam solution. The size and shape seeds determine morphology shells, preferential incorporation low-coordination sites avoidance extended facets. Analysis on particles at different...
We report a new hybrid integration scheme that offers for the first time nanowire-on-lead approach, which enables independent electrical addressability, is scalable, and has superior spatial resolution in vertical nanowire arrays. The fabrication of these arrays demonstrated to be scalable down submicrometer site-to-site spacing can combined with standard integrated circuit technologies. utilize perform electrophysiological recordings from mouse rat primary neurons human induced pluripotent...
Electrodeposited metallic lithium is an ideal negative battery electrode, but nonuniform microstructure evolution during cycling leads to degradation and safety issues. A better understanding of the Li plating stripping processes needed enable practical Li-metal batteries. Here we use a custom microfabricated, sealed liquid cell for in situ scanning transmission electron microscopy (STEM) image first few cycles electrodeposition/dissolution aprotic electrolyte at submicron resolution....
Abstract Observation of growth, synthesis, dynamics, and electrochemical reactions in the liquid state is an important yet largely unstudied aspect nanotechnology. The only techniques that can potentially provide insights necessary to advance our understanding these mechanisms simultaneous atomic-scale imaging quantitative chemical analysis (through spectroscopy) under environmental conditions transmission electron microscope. In this study we describe experimental technical obtain energy...
Pulverization is a major cause of the capacity fade and poor cyclability Sn-based anodes in lithium-ion batteries. We study structural evolution Sn nanoparticles during electrochemical lithiation-delithiation cycling by situ transmission electron microscopy (TEM). The β-Sn size range 79–526 nm are lithiated to crystal Li22Sn5 phase via two-step mechanism, no cracking or fracture observed, distinct from lithiation-induced micron-sized particles. Lithiation can induce aggregation small with...
β-SnSb is known to be a highly stable anode for sodium ion batteries during cycling, but its sodiation–desodiation alloying reactions are poorly understood. Combining in situ TEM with electroanalytical methods, we demonstrate that forms Na3Sb and Na15Sn4 sequence upon sodiation re-forms as desodiation. The negative enthalpy of mixing Sn Sb sufficient cause sequentially deposited bilayers Sn/Sb transform into β-SnSb, resulting comparable cycling stability. good stability results from the...
A planar microbattery that enables various in situ measurements of lithiation 2D materials on the individual-flake scale is developed. large conductivity increase thick MoS2 crystallite due to formation a percolative Mo nanoparticle network embedded Li2S matrix observed. The nanoscale study leads development novel charging strategy for batteries largely improves capacity and cycling performance confirmed bulk MoS2/Li coin cells. As service our authors readers, this journal provides...
We employed an in situ electrochemical cell the transmission electron microscope (TEM) together with ex time-of-flight, secondary-ion mass spectrometry (TOF-SIMS) depth profiling, and FIB–helium ion scanning (HIM) imaging to detail structural compositional changes associated Na/Na+ charging/discharging of 50 100 nm thin films Sb. TOF-SIMS on a partially sodiated Sb film gives Na signal that progressively decreases toward current collector, indicating sodiation does not proceed uniformly....
A new approach to increase root growth in legumes by pre-soaking seeds iron oxide nanoparticle solution.
Using neutron reflectometry, we have determined the thickness and scattering length density profile of electrode–electrolyte interface for high-voltage cathode LiMn1.5Ni0.5O4 in situ at open circuit voltage fully delithiated. Upon exposure to a liquid electrolyte, thin 3.3 nm Li-rich forms due ordering electrolyte on surface. This changes composition, as evident by an increase new layer, with charging condensed layer evolves from being lithium rich one containing much higher concentration F...
Battery cycle life is directly influenced by the microstructural changes occurring in electrodes during charge and discharge cycles. Here, we image situ nanoscale phase evolution negative electrode materials for Li-ion batteries using a fully enclosed liquid cell transmission electron microscope (TEM) to reveal early degradation that not evident charge–discharge curves. To compare electrochemical transformation behavior between three model materials, thin films of amorphous Si, crystalline...
To understand the mechanism that controls low-aspect-ratio lithium deposition morphologies for Li-metal anodes in batteries, we conducted direct visualization of and stripping behavior through nanoscale situ electrochemical scanning transmission electron microscopy (EC-STEM) macroscale-cell electrochemistry experiments a recently developed promising solvate electrolyte, 4 M bis(fluorosulfonyl)imide 1,2-dimethoxyethane. In contrast to published coin cell studies same our revealed low...
The dramatic 50% improvement in energy density that Li-metal anodes offer comparison to graphite conventional lithium (Li)-ion batteries cannot be realized with current cell designs because of failure after a few cycles. Often, is caused by Li dendrites grow through the separator, leading short circuits. Here, we used new characterization technique, cryogenic femtosecond laser cross sectioning and subsequent scanning electron microscopy, observe electroplated morphology accompanying solid...
Multivalent rechargeable metal batteries offer a safer, more sustainable, and higher energy density alternative to lithium-ion batteries, though several challenges remain. Recent demonstrations of room-temperature reversible electrodeposition dissolution Ca indicate that it is possible stabilize metallic anodes with spontaneously formed solid electrolyte interphases (SEIs). However, further progress toward the goal an energy-efficient, long cycle-life anode requires correlating interphase...
Materials characterization is fundamental to our understanding of lithium ion battery electrodes and their performance limitations. Advances in laboratory-based techniques have yielded powerful insights into the structure–function relationship electrodes, yet there still far go. Further improvements rely, part, on gaining a deeper complex physical heterogeneities materials. However, practical limitations inhibit ability combine data directly. For example, some are destructive, thus...
Effective passivation of lithium metal surfaces, and prevention battery-shorting dendrite growth, are critical for implementing lithium-metal-anodes batteries with increased power densities. Nanoscale surface heterogeneities can be "hot spots" where anode breaks down. Motivated by the observation dendrites in pores grain boundaries all-solid batteries, we examine surfaces covered Li(2)O and/or LiF thin films them. Electronic structure calculations show that, at >0.25 V computed equilibrium...
Lithium-metal anodes can theoretically enable 10× higher gravimetric capacity than conventional graphite anodes. However, Li-metal anode cycling has proven difficult due to porous and dendritic morphologies, extensive parasitic solid electrolyte interphase reactions, formation of dead Li. We systematically investigate the effects applied interfacial pressure on performance morphology in recently developed highly efficient 4 M lithium bis(fluorosulfonyl)imide 1,2-dimethoxyethane electrolyte....