A5013595401- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Transition Metal Oxide Nanomaterials
- Advanced Battery Technologies Research
- Supercapacitor Materials and Fabrication
- Gas Sensing Nanomaterials and Sensors
- Semiconductor materials and devices
- Conducting polymers and applications
- Fuel Cells and Related Materials
- Semiconductor materials and interfaces
- Electrocatalysts for Energy Conversion
- Advanced Memory and Neural Computing
- Analytical Chemistry and Sensors
- Advanced battery technologies research
- Extraction and Separation Processes
- Electron and X-Ray Spectroscopy Techniques
- Covalent Organic Framework Applications
- Electrospun Nanofibers in Biomedical Applications
- Magneto-Optical Properties and Applications
- Copper Interconnects and Reliability
- Electric Motor Design and Analysis
- ZnO doping and properties
- Catalytic Processes in Materials Science
- Magnetic Properties and Applications
- Thin-Film Transistor Technologies
University of Colorado Boulder
2014-2024
Kyungpook National University
2017-2024
Sungkyunkwan University
2000-2024
University of Colorado System
2009-2020
Ulsan National Institute of Science and Technology
2016
Korea Institute of Energy Research
2011-2013
Seoul National University
2011-2012
Seoul National University of Science and Technology
2010
National Renewable Energy Laboratory
1999-2007
Massachusetts Institute of Technology
2005
Ionic covalent organic frameworks (ICOFs) have recently emerged as promising candidates for solid-state electrolytes. Herein, we report the first example of a series crystalline imidazolate-containing ICOFs single-ion conducting COF solid electrolyte materials, where lithium cations freely travel through intrinsic channels with outstanding ion conductivity (up to 7.2 × 10–3 S cm–1) and impressively low activation energy (as 0.10 eV). These properties are attributed weak Li ion–imidazolate...
We are currently in the midst of a race to discover and develop new battery materials capable providing high energy-density at low cost. By combining high-performance Si electrode architecture with room temperature ionic liquid electrolyte, here we demonstrate highly energy-dense lithium-ion cell an impressively long cycling life, maintaining over 75% capacity after 500 cycles. Such performance is enabled by stable half-cell coulombic efficiency 99.97%, averaged first 200 Equally as...
Solid-state electrolytes such as Li2S-P2S5 compounds are promising materials that could enable Li metal anodes. However, many solid-state unstable against metallic lithium, and little is known about the chemical evolution of these interfaces during cycling, hindering rational design materials. In this work, operando X-ray photoelectron spectroscopy real-time in situ Auger electron mapping developed to probe formation Li/Li2S-P2S5 solid-electrolyte interphase electrochemical measure...
All-solid-state sodium batteries (ASSSBs) with nonflammable electrolytes and ubiquitous resource are a promising solution to the safety cost concerns for lithium-ion batteries. However, intrinsic mismatch between low anodic decomposition potential of superionic sulfide high operating potentials sodium-ion cathodes leads volatile cathode-electrolyte interface undesirable cell performance. Here we report high-capacity organic cathode, Na4 C6 O6 , that is chemically electrochemically compatible...
Abstract All‐solid‐state lithium ion batteries (LIBs) are ideal for energy storage given their safety and long‐term stability. However, there is a limited availability of viable electrode active materials. Herein, we report truxenone‐based covalent organic framework (COF‐TRO) as cathode materials all‐solid‐state LIBs. The high‐density carbonyl groups combined with the ordered crystalline COF structure greatly facilitate via reversible redox reactions. As result, high specific capacity 268...
The electrochromic mechanism in amorphous tungsten oxide films is studied using Raman scattering measurements. spectra of as-deposited show two strong peaks at 770 and 950 cm−1 due to vibrations the W6+–O W6+=O bonds, respectively, a weaker peak 220 that we attribute W4+–O bonds. When lithium or hydrogen ions electrons are inserted, extra W5+–O W5+=O bonds appear 330 450 cm−1, respectively. Comparison sputtered isotopic a-W16O3−y a-W18O3−y confirms these assignments. We conclude contain...
We report on how electrochromic coloration is affected by oxygen deficient stoichiometries in sputtered amorphous tungsten oxide (a-WO3−y) films. The efficiency increases with increasing deficiency No observed nearly stoichiometric WO3 Raman spectroscopic studies reveal that the number of W5+ states generated lithium insertion deficiency. Furthermore, there are no peaks resulting from lithiated a-WO3−y films near perfect stoichiometry, which consistent absence those conclude depends and...
Cycle stability of solid-state lithium batteries (SSLBs) using a LiCoO2 cathode is improved by atomic layer deposition (ALD) on active material powder with Al2O3. SSLBs LiCoO2/Li3.15Ge0.15P0.85S4/77.5Li2S-22.5P2S5/Li structure were constructed and tested charge-discharge cycling at current density 45 μA cm−2 voltage window 3.3 ∼ 4.3 V (vs. Li/Li+). Capacity degradation during suppressed dramatically employing Al2O3 ALD-coated in the composite cathode. Whereas only 70% capacity retention...
Replacing the liquid electrolyte in a lithium battery with solid can resolve many inherent safety issues as well enable use of next generation electrode materials. Recent research electrolytes, however, has mainly focused on improving ionic conductivity while neglecting compatibility energy dense anodes such metal. Herein, we report new crystalline devised to be inexpensive, highly conductive, and compatible This study presents characterizes an analog Li10GeP2S12 using isovalent ion silicon...
In this study, we report on the effect that an externally applied compressive stress has electrochemical performance of Si anodes. Using compression all-solid-state cell as a convenient format for simulating volume confinement, anodes function been systematically investigated. We verify extent lithiation is limited by confining free expansion nano-Si particles. Volume confinement particles manifested overpotential and results in stable anode lithium-ion batteries. These are foundational lead...
Passivating lithium ion (Li) battery electrode surfaces to prevent electrolyte decomposition is critical for operations. Recent work on conformal atomic layer deposition (ALD) coating of anodes and cathodes has shown significant technological promise. ALD further provides well-characterized model platforms understanding initiated by electron tunneling through a passivating layer. First-principles calculations reveal two regimes transfer adsorbed ethylene carbonate molecules (EC, main...
Using a fully-coupled diffusion-elasticity model with Butler–Volmer surface kinetics, we simulate the insertion of lithium into spherical silicon particles. Simulations predict evolution concentration, displacements, and stresses in particles during first Li. The particle response depends strongly on reaction kinetics resulting can be above tensile failure stress depending size discharge rate.
To deploy solid-state Li batteries in next-generation vehicles, it is essential to develop electrodes with durability, high energy and power. Here we report on nanostructured composite cathode materials that enable cycle durable rate performance. Particle size of TiS2 reduced by planetary ball-milling enhance performance nanocomposite cathodes batteries. The better utilization active material fast kinetics resulting from the reduction allow for highly reversible capacity both room...
The effect of pores in hollow carbon nanofibers (HCNFs) on their electrochemical performance is investigated because the shell itself acts as a reservoir for accommodating Li-ions through intercalation and simultaneously becomes transport medium which migrate into core materials HCNFs. Porous HCNFs (pHCNFs) are prepared by coaxial electrospinning sacrificial solution an emulsified containing islands pore generation. After thermal treatment, systematic study carried out to relate resulting...
The chemical diffusion of lithium ions in a-LixWO3 films is investigated using alternating current impedance spectroscopy and Raman scattering measurements. coefficients increase with increasing x up to x=0.072 then decrease. measurements show that the W6+=O/O–W6+–O ratio also increases at early stage insertion decreases further insertion. We conclude kinetics very closely related ratio.