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Amino acids are important nitrogen-containing compounds and organic carbon components that exist widely in the atmosphere. The formation of atmospheric aerosols is affected by their interactions with amides. The dimers formed by glutamic acid (Glu) or protonated glutamic acid (Glu

Inspired by the concept of “polymer-in-ceramic”, a composite poly(Ɛ-caprolactone) (PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries. The composite with the optimum concentration of 45 wt% LiTFSI and 75 wt% Li1.5Al0.5Ge1.5(PO4)3 (LAGP, NASICON-type structure) exhibits a high ionic conductivity (σi= 0.17 mS cm−1) at 30 °C, a transference number of 0.30, and is stable up to 5.0 V. The composite electrolyte is a flexible and self-standing membrane. Solid-state LiFePO4//Li batteries with this composite electrolyte demonstrate excellent cycling stability with high discharge capacity of 157 mA h g−1, high capacity retention of 96% and coulombic efficiency of 98.5% after 130 cycles at 30 °C and 0.1 C rate. These electrochemical properties are better than other PCL-based all-solid-lithium batteries, and validate the concept of “polymer-in-ceramic” by avoiding the drawback of lower conductivity in prior “polymer-in-ceramic” electrolyte at high concentration of the ceramic.

The development of safe and long-term stable solid polymer electrolytes is a major challenge for all solid-state batteries because good interfacial stability toward electrodes is the main concern. In this paper, a triblock copolymer polystyrene-poly(ethylene glycol)-polystyrene (PS-PEG-PS) is synthesized and investigated as solid polymer electrolyte. This polymer electrolyte exhibits a high ionic conductivity of 1.1 × 10−3 S cm −1 at 70 °C, transference number of 0.17, high degree flexibility, good mechanical strength and thermal stability. The interface stability of the solid-polymer electrolyte is investigated in Li metal cell and the comprehensive electrochemical properties are studied in cells with either LiFePO4 or LiNi0.5Co0.3Mn0.2O2 cathode materials. Good rate capability and excellent cyclability of the solid polymer electrolyte is demonstrated, with an electrochemical stability window extending above 4.5 V vs. Li+/Li. Furthermore, constant voltage impedance measurements give evidence of the better interface stability and rate capability of LiNi0.5Co0.3Mn0.2O2//Li battery. Meanwhile, molecular orbital energy levels calculated by density functional theory are consistent with experiments.

The oxidation mechanism of 4-hydroxy-3-hexanone (CH3CH2C(O)CH(OH)CH2CH3) initiated by NO3 radicals in the nighttime is investigated systematically by applying quantum theoretical methods. According to thermodynamic research, the process of H-abstraction on the -CH- group adjacent to the hydroxyl group is the most dominant pathway with the lowest activation energy. The analysis of Mulliken charge charts and molecular electrostatic potential maps illustrate that C-H bonds are the active sites of the reaction, and the calculated C-H bond dissociation energy of the CH3CH2C(O)CH(OH)CH2CH3 molecule further confirms that α-CH is the most easily activated. Individual rate constants for five H-abstraction pathways are calculated by canonical variational theory coupled with small curvature tunneling method over the temperature range of 260-330 K, and the branching ratios are also evaluated. A total rate constant of 1.18 × 10-15 cm3 per molecule per s is obtained at 298 K, which is in good agreement with the reported experimental value. A negative temperature dependence is observed in the titular reaction. The subsequent degradation processes of the advantageous product alkyl radical (CH3CH2C˙(OH)COCH2CH3) are carried out in a NO-rich environment, and propionic acid, NO2 and ozone are obtained as the major final products. The nighttime atmospheric lifetime of 4-hydroxy-3-hexanone is estimated to be around 19 days, indicating that it has impact at night. The titular reaction rate constants are fitted to a three-parameter Arrhenius formula.

New electrolytes with high electrochemical stability and ionic conductivity are important in the development of lithium ion batteries. Polyethylene carbonate (PEC) is a very promising candidate. Herein, the DFT modeling approach is performed to investigate the coordination structure of Li+ ion in PEC, and the redox potentials of a set of polymer models to assess the effect of polymer monomer unit composition. [Li(PEC)] [Anion] (BF4−, PF6−, ClO4−, TFSI−) are also considered. It is highlighted that the coordination shell of Li+ ion is most likely fully occupied by four carbonyl oxygen atoms of PEC. Next, the carbonate group can lead to greater oxidation stability than ester, ketone and ether group, the length and configuration of alkyl chain affect the redox potential only slightly. Furthermore, the addition of electron-withdrawing groups (-F and -CF3) can increase the oxidation stability of PEC, while the -CN group substitution shows the opposite effect, due to the ring formation or bond breaking of intramolecular structure. All these findings provide important information for understanding the ion-polymer interactions and synthesizing the promising new electrolyte molecules for high-voltage batteries.

Solid-state polymer Li metal batteries have been regarded as a promising candidate for next-generation batteries due to their high-energy densities provided by the Li metal and the improved safety provided by the solid electrolyte. Polyester is one attractive polymer host, which could be an alternative to polyether-based solid electrolyte due to its excellent lithium ion transport ability and wide electrochemical stability window. Here, a BAB-type triblock copolymer is synthesized with poly (propylene carbonate) as A-block and poly (e-caprolactone) as B-block. The triblock copolymer electrolyte exhibits a high ionic conductivity of 3 × 10−5 S cm−1 at 30 °C with a high lithium ion transference number (0.4) and an extremely wide electrochemical window (5 V). A highly stable interface against Li metal is maintained for more than 760 h at a current density of 0.1 mA cm−2. A LiFePO4 cathode based solid state battery delivers a high discharge capacity of 142 mA h g−1 at 0.05C, room temperature, and 161 mA h g−1 at 0.1C, 70 °C with a capacity retention of 90% after 200 cycles. To understand the excellent electrochemical performance, the morphology and chemical information at both anode and cathode interface are characterized and analyzed. The synthesis of this triblock copolymer demonstrates a new direction in developing high ionic conductivity solid polymer electrolyte for solid-state polymer batteries.

This study examines the seasonal variations of tropical cyclogenesis over the South China Sea (SCS) using a genesis potential (GP) index developed by Emanuel and Nolan. How different environmental factors (including low-level vorticity, mid-level relative humidity, vertical wind shear, and potential intensity) contribute to these variations is investigated. Composite anomalies of the GP index are produced for the summer and winter monsoons separately. These composites replicate the observed seasonal variations of the observed frequency and location of tropical cyclogenesis over the SCS. The degree of contribution by each factor in different regions is determined quantitatively by producing composites of modified indices in which only one of the contributing factors varies, with the others set to climatology. Over the northern SCS, potential intensity makes the largest contributions to the seasonal variations in tropical cyclogenesis. Over the southern SCS, the low-level relative vorticity plays the primary role in the seasonal modulation of tropical cyclone (TC) genesis frequency, and the vertical wind shear plays the secondary role. Thermodynamic factors play more important roles for the seasonal variations in tropical cyclogenesis over the northern SCS, while dynamic factors are more important in the seasonal modulation of TC genesis frequency over the southern SCS.

A series of porous carbon samples as electric double layer capacitor electrode materials were prepared by a pyrolysis process using phenol formaldehyde resin (PF) as precursors and KOH/ZnCl 2 as activation agents. Porous carbon samples were characterized by thermogravimetric analysis, X ray diffraction, nitrogen adsorption/desorption isotherms and transmission electron microscopy. The results showed that the KOH/ZnCl 2 /PF mass mixing ratio and activation temperature had a remarkable effect on the porosity, the specific surface area and the pore size of the carbons. The prepared carbon material PC-6 exhibits a high specific capacitance of 141.56 F/g and a average specific energy of 74.13 Wh/kg at a current density of 120 mA/g in the electrolyte of 1 M Et 3 MeNBF 4 /PC, and the average specific energy still remained 49.48 Wh/kg even at a high current density of 2000 mA/g. The excellent electrochemical behavior of PC-6 can be attributed to the highly development pore structure.

Nano-crystallized LiFePO4 has been synthesized with a simple three-step-synthesis technology in the presence of nano-ferric oxide as iron source and polyacence (PAS) as a reductive agent and high conductive carbon source. The use of PAS increases the conductivity and prevents the particles growth. The most feasible calcined temperature and time was investigated and the best cell performance was delivered by the sample calcined at 700 °C for 4 h. This material shows excellent specific capacity and cycle efficiency at high current rates, almost no capacity loss can be observed up to 100 cycles which make it more superior as an optimum power cell cathode material.

The effect of the molecular structures of a series of π-conjugated rigid rod oligomers in phenylene vinylene dimers on electronic structures has been investigated by utilizing electrochemistry and spectroscopy along with quantum chemical calculations. The redox potential of oligomers varies with different substituents. The ionization potential changes from 5.49 to 4.92 eV, and the electron affinity from 2.59 to 2.29 eV, indicating that the substituents could considerably alter both the HOMO and LUMO levels.

Molecules with D-π-A structures are drawing increased attention for applications in organic electronic devices due to their distinct optoelectronic properties. A study of a new series of bipolar fluorophores that have been chemically modified for use as highly efficient nondoped blue organic light-emitting diodes (OLEDs) has been carried out based on existing molecular structures and a literature survey. The aim of this study is to provide a profound interpretation of the optical and electronic properties and the structure–property relationships of a series of new bipolar fluorophores. The study also aims to predict the photophysical and optoelectronic properties of the new fluorophores. The density functional theory (DFT) has been confirmed as reliable, especially in predicting the properties of unknown products. The geometry and the electronic structure of these molecules in the ground state were studied with DFT and ab initio HF, whereas the lowest singlet excited-state geometries were optimized by ab initio singlet configuration interaction (CIS). The absorption and emission spectra, both in the gas phase and in THF, and the lowest singlet excited energies were calculated by employing the time-dependent density functional theory (TDDFT) and the polarizable continuum model (PCM). To precisely predict the charge-transporting and charge-confining properties of the new fluorophores, three-layered devices have been simulated. The results show that the molecular geometries, HOMOs, LUMOs, energy gaps, ionization potentials (IP), electron affinities (EA), radiative lifetimes ( τ ), absorption and emission spectra are all tuned by chemical modifications with different π-conjugated bridges. The results also show that these molecular materials could be used as bipolar light-emitting materials for blue and deep-blue OLEDs.