Experimental and theoretical investigations on 4,5-dimethyl-[1,3]dioxol-2- one as solid electrolyte interface forming additive for lithium-ion batteries

4,5-Dimethyl-[1,3]dioxol-2-one (DMDO) was used as a novel electrolyte additive for lithium-ion batteries. The effect of DMDO on the formation of the solid electrolyte interface (SEI) on anode and cathode of MCMB/LiNi 0.8Co0.2O2 cells was investigated via a combination of electrochemical methods, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. It is found that cells with electrolyte containing 2% DMDO have better capacity retention than cells without DMDO and this improved performance is ascribed to the assistance of DMDO in forming better SEIs on anode and cathode. DMDO-decomposition products are identified experimentally on the surface of the anode and cathode and supported by theoretical calculations. © 2010 Elsevier Ltd. All rights reserved

Investigation and application of lithium difluoro(oxalate)borate (LiDFOB) as additive to improve the thermal stability of electrolyte for lithium-ion batteries

Lithium difluoro (oxalate) borate (LiDFOB) is used as thermal stabilizing and solid electrolyte interface (SEI) formation additive for lithium-ion battery. The enhancements of electrolyte thermal stability and the SEIs on graphite anode and LiFePO4 cathode with LiDFOB addition are investigated via a combination of electrochemical methods, nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared-attenuated total reflectance (FTIR-ATR), as well as density functional theory (DFT). It is found that cells with electrolyte containing 5% LiDFOB have better capacity retention than cells without LiDFOB. This improved performance is ascribed to the assistance of LiDFOB in forming better SEIs on anode and cathode and also the enhancement of the thermal stability of the electrolyte. LiDFOB-decomposition products are identified experimentally on the surface of the anode and cathode and supported by theoretical calculations. © 2010 Elsevier B.V. All rights reserved

Transcriptome profiling reveals histone deacetylase 1 gene overexpression improves flavonoid, isoflavonoid, and phenylpropanoid metabolism in Arachis hypogaea hairy roots

Background The peanut (Arachis hypogaea) is a crop plant of high economic importance, but the epigenetic regulation of its root growth and development has not received sufficient attention. Research on Arabidopsis thaliana has shown that histone deacetylases (HDACs) are involved in cell growth, cell differentiation, and stress response. Few studies have focused on the role of HDACs in the root development of other plants, particularly crop plants. In earlier studies, we found large accumulations of A. hypogaea histone deacetylase 1 (AhHDA1) mRNA in peanut roots. However, we did not explore the role of AhHDA1 in peanut root development. Methods In this paper, we investigated the role of the peanut AhHDA1 gene and focused on the effect of altered AhHDA1 expression in hairy roots at both the phenotypic and transcriptional levels. We analyzed the transformation of A. hypogaea hairy roots using Agrobacterium rhizogenes and RNA sequencing to identify differentially expressed genes that were assigned to specific metabolic pathways. Transgenic hairy roots were used as experimental material to analyze the downstream genes expression and histone acetylation levels. To thoroughly understand AhHDA1 function, we also simultaneously screened the AhHDA1-interacting proteins using a yeast two-hybrid system. Results AhHDA1-overexpressing hairy roots were growth-retarded after 20 d in vitro cultivation, and they had a greater accumulation of superoxide anions and hydrogen peroxide than the control and RNAi groups. AhHDA1 overexpression in hairy roots accelerated flux through various secondary synthetic metabolic pathways, as well as inhibited the primary metabolism process. AhHDA1 overexpression also caused a significant upregulation of genes encoding the critical enzyme chalcone synthase (Araip.B8TJ0, CHS) in the flavonoid biosynthesis pathway, hydroxyisoflavanone synthase (Araip.0P3RJ) in the isoflavonoid biosynthesis pathway, and caffeoyl-CoA O-methyltransferase (Aradu.M62BY, CCoAOMT) in the phenylpropanoid biosynthesis pathway. In contrast, ferredoxin 1 (Araip.327XS), the polypeptide of the oxygen-evolving complex of photosystem II (Araip.N6ZTJ), and ribulose bisphosphate carboxylase (Aradu.5IY98) in the photosynthetic pathway were significantly downregulated by AhHDA1 overexpression. The expression levels of these genes had a positive correlation with histone acetylation levels. Conclusion Our results revealed that the relationship between altered gene metabolism activities and AhHDA1 overexpression was mainly reflected in flavonoid, isoflavonoid, and phenylpropanoid metabolism. AhHDA1 overexpression retarded the growth of transgenic hairy roots and may be associated with cell metabolism status. Future studies should focus on the function of AhHDA1-interacting proteins and their effect on root development

Why Do Sulfone-Based Electrolytes Show Stability at High Voltages? Insight from Density Functional Theory

Sulfone-based electrolytes have attracted a great attention due to their high oxidation stability comparing to conventional carbonates. However, the ab initio calculated oxidation potentials (<i>E</i>_ox) of isolated sulfones are lower than those for carbonates. To understand this contradiction, the oxidations of three carbonates and eleven sulfones in a presence of anions and other solvent molecules have been investigated by the density functional theory calculations with a polarized continuum model. Importantly, we found that the <i>E</i>_ox of some of the sulfones show surprisingly high stability toward the presence of anions and another solvent, which is the key factor of high oxidation stability of these electrolytes compared to carbonates. Finally, the way to design new high oxidation stability sulfones by modifying their functional groups is discussed

Preparation of magnetic Levextrel resin for cadmium(II) removal

In the present paper, the authors investigated the adsorption of cadmium on magnetic Levextrel resin containing about 352 mg g(-1) Cyanex 272 (C272) as adsorbent. Magnetic Levextrel resin (mPst-DVB-C272) was synthesized through adding Cyanex 272 and oleic acid-coated magnetite nanoparticles directly to the mixture of styrene (st) and divinylbenzene (DVB) monomers during the bead polymerization. It is a new method for preparing magnetic Levextrel resins with less organic solvents and less steps MPst-DVBC272 was characterized with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravity (TG) and differential thermal gravity (DTG), and vibrating sample magnetometry (VSM). Then mPst-DVB-C272 was applied to remove cadmium. The effects of pH, initial Cd(II) concentration, and contact time on Cd(II) removal were investigated in batch experiments. The optimized pH value for the Cd(II) adsorption was 6.5. The maximum adsorption capacity was 18.77 mg g(-1) for mPst-DVB-C272. The adsorption reached equilibrium within 90 min and the experimental data fit the pseudo-second-order model. (C) 2021 Elsevier B.V. All rights reserved

Reference intervals of Cyfra21-1 and CEA in healthy adult Han Chinese population

Objective: This study aimed to establish the reference intervals of Cyfra21-1 and CEA for the local screening populations using a chemiluminescence method. Methods: A total of 4845 healthy adults and 190 lung cancer patients were included from the First Hospital of Hebei Medical University. The levels of Cyfra21-1 and CEA were measured to establish the local reference intervals. Results: The upper limit reference intervals for Cyfra21-1 and CEA were determined as 3.19 ng/ml and 3.13 ng/ml, respectively. Notably, both Cyfra21-1 and CEA levels were found to be higher in males than in females. Additionally, both biomarkers showed an increasing trend with age.In terms of diagnostic efficacy, the receiver operating characteristic (ROC) curve areas for Cyfra21-1, CEA, and their combination in lung cancer were 0.86, 0.73, and 0.91, respectively. Conclusion: Our study revealed that the reference intervals of Cyfra21-1 and CEA in the local population differed from the established reference intervals. Furthermore, both biomarkers exhibited gender-dependent variations and demonstrated a positive correlation with age. Combining the two biomarkers showed potential for improving the diagnosis rate of lung cancer

Density Functional Theory Study of the Role of Anions on the Oxidative Decomposition Reaction of Propylene Carbonate

The oxidative decomposition mechanism of the lithium battery electrolyte solvent propylene carbonate (PC) with and without PF₆^– and ClO₄^– anions has been investigated using the density functional theory at the B3LYP/6-311++G(d) level. Calculations were performed in the gas phase (dielectric constant ε = 1) and employing the polarized continuum model with a dielectric constant ε = 20.5 to implicitly account for solvent effects. It has been found that the presence of PF₆^– and ClO₄^– anions significantly reduces PC oxidation stability, stabilizes the PC–anion oxidation decomposition products, and changes the order of the oxidation decomposition paths. The primary oxidative decomposition products of PC–PF₆^– and PC–ClO₄^– were CO₂ and acetone radical. Formation of HF and PF₅ was observed upon the initial step of PC–PF₆^– oxidation while HClO₄ formed during initial oxidation of PC–ClO₄^–. The products from the less likely reaction paths included propanal, a polymer with fluorine and fluoro-alkanols for PC–PF₆^– decomposition, while acetic acid, carboxylic acid anhydrides, and Cl^– were found among the decomposition products of PC–ClO₄^–. The decomposition pathways with the lowest barrier for the oxidized PC–PF₆^– and PC–ClO₄^– complexes did not result in the incorporation of the fluorine from PF₆^– or ClO₄^– into the most probable reaction products despite anions and HF being involved in the decomposition mechanism; however, the pathway with the second lowest barrier for the PC–PF₆^– oxidative ring-opening resulted in a formation of fluoro-organic compounds, suggesting that these toxic compounds could form at elevated temperatures under oxidizing conditions

Nanopatterning of Electrode Surfaces as a Potential Route to Improve the Energy Density of Electric Double-Layer Capacitors: Insight from Molecular Simulations

Electrostatic double-layer capacitors (EDLCs) with room-temperature ionic liquids (RTILs) as electrolytes are among the most promising energy storage technologies. Utilizing atomistic molecular dynamics simulations, we demonstrate that the capacitance and energy density stored within the electric double layers (EDLs) formed at the electrode–RTIL electrolyte interface can be significantly improved by tuning the nanopatterning of the electrode surface. Significantly increased values and complex dependence of differential capacitance on applied potential were observed for surface patterns having dimensions similar to the ions' dimensions. Electrode surfaces patterned with rough edges promote ion separation in the EDL at lower potentials and therefore result in increased capacitance. The observed trends, which are not accounted for by the current basic EDL theories, provide a potentially new route for optimizing electrode structure for specific electrolytes