A5085903184- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced Battery Technologies Research
- Supercapacitor Materials and Fabrication
- Gas Sensing Nanomaterials and Sensors
- Extraction and Separation Processes
- Advanced Photocatalysis Techniques
- Semiconductor materials and devices
- Electrocatalysts for Energy Conversion
- Copper-based nanomaterials and applications
- Quantum Dots Synthesis And Properties
- Fuel Cells and Related Materials
- ZnO doping and properties
- Semiconductor materials and interfaces
- Conducting polymers and applications
- Advanced Chemical Sensor Technologies
- Advanced battery technologies research
- Transition Metal Oxide Nanomaterials
- Analytical Chemistry and Sensors
- Electron and X-Ray Spectroscopy Techniques
- Catalytic Processes in Materials Science
- Advanced Memory and Neural Computing
- Graphene research and applications
- Perovskite Materials and Applications
- Recycling and Waste Management Techniques
Chungnam National University
2016-2025
Daejeon University
2016-2020
Government of the Republic of Korea
2019-2020
University of Illinois Chicago
2013-2018
Argonne National Laboratory
2018
Lawrence Berkeley National Laboratory
2011-2016
Seoul National University
2005-2010
Kumoh National Institute of Technology
2005
The preparation of 2D layered SnS2 nanoplates with nanoscale lateral confinement (less than 150 nm) is described (see figure). Their unique characteristics, including finite morphology, make the discharge capacity Li ion batteries remarkably high-almost close to theoretical possible value.
SnO2 nanoparticles with different sizes of ∼3, ∼4, and ∼8 nm were synthesized using a hydrothermal method at 110, 150, 200 °C, respectively. The results showed that the ∼3 nm-sized had superior capacity cycling stability as compared to ∼4 ones. exhibited an initial 740 mAh/g negligible fading. electrochemical properties these those thin-film analogues. Transmission electron microscopy (TEM) X-ray diffraction (XRD) confirmed after tests did not aggregate into larger Sn clusters, in contrast observed
The capacity limitations of insertion‐compound cathodes has motivated interest in a sulfur cathode for rechargeable battery cell with metallic‐lithium anode; but irreversible loss owing to solubility intermediate Li 2 S x (x = 2–8) polysulfides the organic‐liquid electrolytes used prevented practical application. A dual‐function structure consisting layered tungsten disulfide (WS ) supported both on current collector and carbon cloth interlayer (CCl) gives excellent performance lithium...
Ultrathin conformal coatings of the lithium ion conductor, aluminum oxide (LiAlO2), were evaluated for their ability to improve electrochemical stability LiNi0.5Mn1.5O4/graphite Li-ion batteries. Electrochemical impedance spectroscopy confirmed conducting character LiAlO2 films. Complementary simulations activation barriers in these layers match experimental results very well. films subsequently separately deposited onto LiNi0.5Mn1.5O4 and graphite electrodes. Increased was observed,...
Electrochemical oxidation of carbonate esters at the Li(x)Ni(0.5)Mn(1.5)O(4-δ)/electrolyte interface results in Ni/Mn dissolution and surface film formation, which negatively affect electrochemical performance Li-ion batteries. Ex situ X-ray absorption (XRF/XANES), Raman, fluorescence spectroscopy, along with imaging Li(x)Ni(0.5)Mn(1.5)O(4-δ) positive graphite negative electrodes from tested batteries, reveal formation a variety Mn(II/III) Ni(II) complexes β-diketonate ligands. These metal...
Direct evidence of Mg2+ intercalation into a spinel-type Mn2O4 is provided. By combining tools with different sensitivities, from atomic-resolution X-ray spectroscopy to bulk diffraction, it demonstrated that reversibly occupies the tetrahedral sites spinel structure through reduction Mn when electrochemical reaction performed. As service our authors and readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed may be re-organized for...
Catalytic supremacy of Pt-single atoms achieved by CeO<sub>x</sub>–TiO<sub>2</sub>interfaces.
Abstract Functional electrodes for batteries share a common design rule by which high electronic and ionic conductivity pathways must exist throughout the electrode in its pristine state. Notable amounts of conductive carbon additive composite are usually included to form an electronically matrix. However, excellent rate cycling performance has been achieved composed insulating Li 4 Ti 5 O 12 without any additives. This behavior opens possibility new paradigm designing functional is not...
Abstract Polysulfide dissolution into the electrolyte and poor electric conductivity of elemental sulfur are well‐known origins for capacity fading in lithium–sulfur batteries. Various smart electrode designs have lately been introduced to avoid these mechanisms, most which demonstrate significantly improved cycle life. Nevertheless, an in‐depth understanding on effect microstructure nanoscale electron transport near is currently lacking. In this study, authors report organized nanocomposite...
Monodisperse Sn spherical nanocrystals of 10.0 ± 0.2 nm were prepared in dispersible colloidal form. They used as a model platform to study the impact size on accommodation colossal volume changes during electrochemical lithiation using ex situ transmission electron microscopy (TEM). Significant mechanical damage was observed after full lithiation, indicating that even crystals at these very small dimensions are not sufficient prevent particle pulverization compromises electrode durability.
Abstract Battery function is determined by the efficiency and reversibility of electrochemical phase transformations at solid electrodes. The microscopic tools available to study chemical states matter with required spatial resolution specificity are intrinsically limited when studying complex architectures their reliance on two-dimensional projections thick material. Here, we report development soft X-ray ptychographic tomography, which resolves in three dimensions 11 nm resolution. We an...
We first report on the copolymerization of sulfur and allyl-terminated poly(3-hexylthiophene-2,5-diyl) (P3HT) derived by Grignard metathesis polymerization. This is enabled conversion radicals formed thermolytic cleavage S8 rings with allyl end-group. The formation a C–S bond in copolymer characterized variety methods, including NMR spectroscopy, size exclusion chromatography, near-edge X-ray absorption fine spectroscopy. S-P3HT applied as an additive to cathode material lithium–sulfur...
Lithium–sulfur (Li–S) batteries are expected to overcome the limit of current energy storage devices by delivering high specific with low material cost. However, potential Li–S has not yet been realized because several technical barriers. Poor electrochemical performance is mainly attributed electrical conductivity fully charged and discharged species, irreversible loss polysulfide anions decrease in number electrochemically active reaction sites during battery operation. Here, we report...
Abstract In 2 O 3 nanostructure sensors were fabricated by arc-discharging a source composed of graphite tube containing indium. The NO gas sensing properties, as well the morphology, structure, and electrical examined at room temperature under UV light illumination. particular, response recovery kinetics sensor various intensities studied. maximum signal was observed an intermediate intensity, which could be corroborated nano-size effect based on conduction model resistive chemical nano...
The practical implementation of Li–S technology has been hindered by short cycle life and poor rate capability owing to deleterious effects resulting from the varied solubilities different Li polysulfide redox products. Here, we report preparation utilization composites with a sulfur-rich matrix molybdenum disulfide (MoS2) particulate inclusions as cathode materials mitigate dissolution products via MoS2 acting “polysulfide anchors”. In situ composite formation was completed facile, one-pot...
The performance of battery electrode materials is strongly affected by inefficiencies in utilization kinetics and cycle life as well size effects. Observations phase transformations these with high chemical spatial resolution can elucidate the relationship between processes mechanical degradation. Soft X-ray ptychographic microscopy combined absorption spectroscopy electron creates a powerful suite tools that we use to assess morphological changes lithium iron phosphate (LiFePO4) micro-...
The effects of hydroxyl quenching were examined on the photoluminescence properties SnO2:Eu3+ nanoparticles. High-quality nanoparticles simply synthesized from SnCl4, EuCl3, and ethylene glycol. spectra showed a reddish orange emission, which gradually increased with calcination temperature in range 700 to 1000 °C. As varied, change OH-/O2- integrated-intensity ratios X-ray photoelectron spectroscopy (XPS) was qualitatively consistent that intensities. samples obtained after hydrothermal...
A series of samples LiNi1/2Mn3/2O4 were prepared by different synthetic methods. They displayed a variety particle sizes and shapes, from nanometric to micrometric, with anisotropies assemblies. The evaluation their performance as electrodes in lithium metal half cells showed that the best at fast rate 1 C is obtained BM900C, which consisted micron-size octahedral particles. It outperformed sizes, which, same time, also worse coulombic efficiencies. Nonetheless, low efficiency 88.9% for...
An effective way of synthesizing graphene-wrapped Li4Ti5O12 particles was developed by solid-state reaction between graphene oxide-wrapped P25 (TiO2) and Li2CO3. Compared to the previously reported graphene/Li4Ti5O12 composites, prior wrapping TiO2 with subsequent chemical lithiation led more effectively confined Li4Ti5O12. The tightly bound exhibited a remarkable specific capacity 147 mA h g−1 at rate 10 C (1 = 175 g−1) after 100 cycles. This capability is one highest values among 150 ± 50...
Abstract This paper introduces oxygen‐deficient black TiO 2 with hierarchically ordered porous structure fabricated by a simple hydrogen reduction as carbon‐ and binder‐free cathode, demonstrating superior energy density stability. With the high electrical conductivity derived from oxygen vacancies or Ti 3+ ions, this unique electrode features micrometer‐sized voids mesoporous walls for effective accommodation of Li O toroid rapid transport reaction molecules without being clogged. In highly...