A vanadium pentoxide electrode is prepared in the amorphous form (a-V2O5), and its electrode performances are compared to those for its crystalline counterpart (c-V2O5). The a-V2O5 electrode outperforms c-V2O5 in several ways. First, it is free from irreversible phase transitions and Li trapping, which evolve in c-V2O5, probably due to the lack of interactions between the inserted Li+ ions/electrons and V2O5 matrix. Second, the absence of Li trapping allows a reversible capacity amounting to >600 mA h g–1, which is larger than that given by c-V2O5. Third, it shows an excellent rate property. The notably high reversible capacity and rate capability seem to be due to Li storage at vacant sites that are ill-defined but numerous in a-V2O5, which Li+ ions can easily access. However, irreversible capacity of a-V2O5 is appreciable in the first cycle due to a parasitic Li reaction with surface hydroxyl groups. Treatment with n-butyllithium can suppress the irreversible capacity by removing the surface hydroxyl groups.

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BackgroundEnterovirus 71 (EV71) is a major causative agent of hand-foot-mouth disease (HFMD) and also causes severe neurological complications, leading to fatality in young children. However, no effective therapy is currently available for the treatment of this infection.MethodsWe identified small-molecule inhibitors of EV71 from a screen of 968 Food and Drug Administration (FDA)-approved drugs, with which clinical application for EV71-associated diseases would be more feasible, using EV71 subgenomic replicon system. Primary hits were extensively evaluated for their antiviral activities in EV71-infected cells.ResultsWe identified micafungin, an echinocandin antifungal drug, as a novel inhibitor of EV71. Micafungin potently inhibits the proliferation of EV71 as well as the replication of EV71 replicon in cells with a low micromolar IC50 (~5 μM). The strong antiviral effect of micafungin on EV71 replicon and the result from time-of-addition experiment demonstrated a targeting of micafungin on virion-independent intracellular process(es) during EV71 infection. Moreover, an extensive analysis excluded the involvement of 2C and 3A proteins, IRES-dependent translation, and also that of polyprotein processing in the antiviral effect of micafungin.ConclusionsOur research revealed a new indication of micafungin as an effective inhibitor of EV71, which is the first case reporting antiviral activity of micafungin, an antifungal drug.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-016-0557-8) contains supplementary material, which is available to authorized users.

This work describes the beneficial effects given by the allyl sulfide (AS)-derived surface film on the low-temperature performances of graphite electrode and the film-forming mechanism. Adding a small amount of allyl sulfide as an electrolyte additive into a Li/graphite cell increases the reversible capacity of graphite electrode to three times larger than that of the AS-free cell at −30 • C. Lithium plating is also suppressed by adding AS into the background electrolyte. An impedance analysis reveals that the charge transfer resistance is significantly lower in the AS-added cell at low-temperatures. When the graphite electrode is soaked in the AS-added electrolyte, allyl sulfide is spontaneously oxidized to produce the sulfur-containing surface film. The as-generated film is then electrochemically reduced during the first lithiaiton period to produce another type of the sulfur-containing film. After repeated cycling, a carbon-rich sulfur-containing film is generated near the graphite surface, while the decomposition products of background electrolyte are deposited in the outer surface region. The presence of the carbon-rich sulfur-containing film near the graphite surface seems to be responsible for the facilitation of charge transfer reaction at low temperatures.Adequate low-temperature performance is a key requirement of energy storage devices for hybrid electric vehicles (HEVs) and electric vehicles (EVs). Lithium-ion batteries (LIBs) are the most promising candidate for these applications due to their relatively high energy and power density compared with other power sources. However, for these weather-sensitive applications, LIBs must overcome the drastic decrease in reversible capacity at low-temperatures. 1,2 It is reported that, in severe conditions (< −40 • C), a commercial 18650 cells deliver only 5% of its energy density in comparison to its value at 20 • C. 3 Graphite, the preferred negative electrode for LIBs, is well-known for poor electrochemical performance below −20 • C. 4-6 There are many possible causes for this undesirable feature; increased viscosity and reduced Li + conductivity in electrolytes, 7 the enlarged resistance of the passivation layer called solid electrolyte interphase (SEI), 8 the increase of charge transfer resistances (R CT ) at the electrode/electrolyte interface, 6 and the decrease of solid-state Li + diffusion rate. 9 Due to the enlarged R CT for Li intercalation at graphite/electrolyte interfaces and slower Li + diffusion into graphene layers at low temperatures, Li + ions are reduced into Li metal (lithium plating) on graphite surface instead of intercalation, which causes a serious safety concern. Several approaches to improve low-temperature performances of graphite negative electrode have been pursued in recent studies. 4,6,10,11 The formation of SEI film on graphite electrodes is unavoidable because the working voltage of graphite electrodes is beyond the thermodynamic stability window of typical organic electrolytes. The SEI film passivates the graphite surface, the...

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Systematic experiments were performed on the synthesis of nano-structured LiFePO4 by the solvothermal route using different reaction times of 2, 8, 16, and 36 h at a moderate temperature of 240°C. The physical, chemical and electrochemical properties of the LiFePO4 samples were investigated by powder X-ray Diffraction, field-emission SEM/TEM, inductively coupled plasma atomic emission spectrometry (ICP-AES), particle size distribution measurement, and galvanostatic tests. The crystal growth mechanism during the solvothermal reaction was deemed to consist of four stages, viz. the dissolution of the precursor and nucleation, growth and aggregation, partial dissolution, and complete crystallization.

High voltage positive electrodes for lithium ion batteries have suffered from continuous oxidation of the electrolyte during cycling, which largely offsets the benefits of high energy and power densities. In this work, the electrolyte oxidation and concomitant film deposition/dissolution behaviors were investigated on Pt electrode by using linear sweep voltammetry (LSV), electrochemical quartz crystal microbalance (EQCM), and X-ray photoelectron spectroscopy (XPS). Two characteristics were identified. First, film deposition is relatively unfavorable at higher potentials (>4.7 V vs. Li/Li + ) because the oxidation products are mostly gaseous or soluble species. Second, the concentration of inorganic species decreases in the surface film as the potential increases, which is likely dissolved by HF or polar species. The dominance of gaseous or soluble products and the partial dissolution of the surface film, are two characteristics which hamper passivation of the electrode surface, leading to severe electrolyte oxidation at the high potentials.

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