Combining Ester Solvent-Containing Electrolytes with All-Active Material Electrodes for High Current Density Lithium-Ion Batteries

Lithium (Li)-ion batteries are a leading rechargeable energy storage technology due to their high volumetric and gravimetric energy density. Increasing the electrode thickness is one method to increase the energy density at the cell level, regardless of the specific cell chemistry. All-active material (AAM) electrodes, fabricated via hydraulic compression and mild sintering of only electroactive material (no binders or conductive additives), provide a robust route to achieve thick Li-ion electrodes. The removal of additives also facilitates improved ion transport in the electrode microstructure, which reduces tortuosity and improves the retention of electrochemical capacity at increased cycling rates. However, due to the high thickness of the electrodes, ionic overpotentials are still typically the largest source of cell polarization. To mitigate that polarization and improve retention of capacity at increasing current density, herein, AAM electrodes were combined with high-conductivity ester-based electrolytes. Relative to prior reports with the same or higher areal loadings of the Li-ion electrodes, the delivered capacity was retained at relatively higher rates of charge

Stable Multicomponent Multiphase All Active Material Lithium-Ion Battery Anodes

Due to their high energy density, lithium-ion batteries have been the state-of-the-art energy storage technology for many applications. Energy density can be further improved by engineering of the electrode architecture and microstructure, in addition to more common improvements via materials chemistry. All active material (AAM) electrodes consist of only the electroactive material that stores energy, and such electrodes have advantages to conventional composite processing with regards to improved mechanical stability at increased thicknesses and ion transport properties. However, the absence of binders and composite processing makes the electrode more vulnerable to electroactive materials with volume change upon cycling. Also, the electroactive material must have sufficient electronic conductivity to avoid large matrix electronic overpotentials during electrochemical cycling. TiNb2O7 (TNO) and MoO2 (MO) are electroactive materials with potential advantages as AAM electrodes due to relatively high volumetric energy density. TNO has higher energy density, and MO has much higher electronic conductivity, and thus a multicomponent blend of these materials was evaluated as an AAM anode. Herein, blends of TNO and MO as AAM anodes were investigated, where this is the first use of a multicomponent AAM anode. Electrodes that had both TNO and MO had the highest volumetric energy density, rate capability, and cycle life relative to single component TNO and MO anodes. Thus, using multicomponent materials provides a route to improve AAM electrochemical systems

Modifying Lipophilicities of Zn(II) Coordination Species by Introduction of Ancillary Ligands: A Supramolecular Chemistry Approach

A homologous series of neutral Zn(II) coordination complexes including Zn(PNO)2 (1), Zn(PNO)2(3-Br-Py) (2), [Zn(PNO)2(1,10-phenanthroline)](H2O)5/3 (3), and Zn(PNO)2(2,2′-Bipy) (4), where PNO = deprotonated 2-hydroxypyridine N-oxide, have been synthesized and characterized. Complexes 2−4 were prepared by reacting ancillary ligands with complex 1. Ancillary ligands form coordinate bonds to transition metal center-Zn(II). Their solid-state crystal structures, solubilities, lipophilicities, and association−dissociation properties in aqueous phase have been investigated in the current work. Diffusion-ordered NMR data suggested that association−dissociation properties of mixed-ligand Zn(II) coordination complexes in the aqueous phase are greatly dependent upon the coordination mode of ancillary ligands to Zn(II). By introduction of ancillary ligands, we can rationally modify lipophilicities and solubilities of mixed-ligand Zn(II) coordination complexes on the basis of log P of the ancillary ligand. These in vitro data highlighted the approach of forming mixed-ligand coordination species in fine-tuning physical-chemical properties of Zn(II) species for medicinal applications

Modifying Lipophilicities of Zn(II) Coordination Species by Introduction of Ancillary Ligands: A Supramolecular Chemistry Approach

A homologous series of neutral Zn(II) coordination complexes including Zn(PNO)2 (1), Zn(PNO)2(3-Br-Py) (2), [Zn(PNO)2(1,10-phenanthroline)](H2O)5/3 (3), and Zn(PNO)2(2,2′-Bipy) (4), where PNO = deprotonated 2-hydroxypyridine N-oxide, have been synthesized and characterized. Complexes 2−4 were prepared by reacting ancillary ligands with complex 1. Ancillary ligands form coordinate bonds to transition metal center-Zn(II). Their solid-state crystal structures, solubilities, lipophilicities, and association−dissociation properties in aqueous phase have been investigated in the current work. Diffusion-ordered NMR data suggested that association−dissociation properties of mixed-ligand Zn(II) coordination complexes in the aqueous phase are greatly dependent upon the coordination mode of ancillary ligands to Zn(II). By introduction of ancillary ligands, we can rationally modify lipophilicities and solubilities of mixed-ligand Zn(II) coordination complexes on the basis of log P of the ancillary ligand. These in vitro data highlighted the approach of forming mixed-ligand coordination species in fine-tuning physical-chemical properties of Zn(II) species for medicinal applications

Flexible hyperspectral surface plasmon resonance microscopy

   Dataset of the raw hyperspectral SPR datacube supporting the article titled 'Flexible Hyperspectral Surface Plasmon Resonance Microscopy'.</p

Immobilization of a Quinonoid Rhodium Catalyst on Silica Gel by the Surface Sol−Gel Process and Catalytic Activity for Phenylacetylene Polymerization

A metal alkoxide monolayer was formed on the surface of silica gel by the SSG process (surface sol−gel). Quinonoid rhodium complexes possessing an acidic −OH group were immobilized on the alkoxide layer by deprotonation and subsequent formation of strong M−O (quinonoid) bonds (M = Ti, Zr). The silica-gel-supported rhodium catalyst shows a high reactivity for the stereospecific polymerization of phenylacetylene to cis-transoidal polyphenylacetylene

Flexible Narrowband Ultraviolet Photodetectors with Photomultiplication Based on Wide Band Gap Conjugated Polymer and Inorganic Nanoparticles

Lightweight and flexible ultraviolet (UV) photodetectors (PDs) have wide applications and have attracted more attention. PDs using organic and inorganic nanocomposites as active layers with a photodiode configuration could achieve photomultiplication and narrowband photoresponse via the control of microstructure and thickness of active layers. Here, we fabricated flexible UV PDs on indium tin oxide-coated poly­(ethylene terephthalate) substrates with a nanocomposite active layer composed of ZnO nanoparticles blended with a wide band gap conjugated polymer, poly­[(9,9-dioctylfluorenyl-2,7-diyl)-<i>alt</i>-<i>co</i>-(bithiophene)] (F8T2). As a result of the wavelength-dependent penetration depth of light in the active layer, the fabricated flexible UV PDs showed two narrow response peaks at 360 and 510 nm under reverse biases in the external quantum efficiency (EQE) spectra with full width at half maximum (FWHM) less than 20 nm. Both responses exhibited greater than 100% EQE, indicating a photomultiplication effect, whereas the UV response at 360 nm was 10 times stronger under −15 V bias. The fabricated flexible UV PDs were bent under both tensile and compressive stress to a curvature of 2.1 cm^–1, each with 50 repetitions. The peak specific detectivity (<i>D</i>*) only decreased by about 5% in total, the FWHM was well retained below 20 nm and the response speed remained almost constant after two types of bending, demonstrating mechanical flexibility and photoresponse stability of the fabricated flexible UV PDs. The photodiode configuration with nanocomposite active layers offers a promising route to make flexible and conformable narrowband, photomultiplication-type photodetectors for modern applications

Supplementary document for Surface plasmon resonance gas sensor with nanoporous gold film - 5970125.pdf

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Surface Modification of Fe₃O₄ and FePt Magnetic Nanoparticles with Organometallic Complexes

Hexane solutions of Fe3O4 and FePt nanoparticles (NPs) having both oleylamine and oleic acid as surfactants were surface modified by treatment with a DMSO solution of [(η6-hydroquinone)Mn(CO)3]BF4, which is readily deprotonated by the oleylamine to [(η5-semiquinone)Mn(CO)3]. The latter complex binds to the NP by replacing the protonated oleylamine, which likely forms a bilayer with the alkyl chains of the oleic acid on the NP surface. The resulting surface-modified assembly is soluble in DMSO. With FePt nanoparticles, [(η5-semiquinone)Mn(CO)3] coordinates to the Pt atoms and the IR frequency of the tricarbonyls differs from that obtained with Fe3O4 nanoparticles, in which coordination is to the iron