RESUMO
We synthesized Li and Na monocarborate salts with minimal protic impurities and reassessed their electrochemical windows. Na salts display higher efficiency for metal deposition/stripping and are more oxidatively stable than Li salts. This strong cation effect is rationalized in terms of differences in charge density between Li+ and Na+ cations.
RESUMO
Passivation of magnesium metal anode is one of the critical challenges for the development of magnesium batteries. Here we investigated the passivation process of an intermetallic anode: Mg3Bi2 synthesized by solid-state and thin film process. The Mg3Bi2 composite electrode shows excellent reversibility in magnesium bis(trifluoromethansulfonylamide) dissolved in acetonitrile, while Mg3Sb2, which has same crystal structure and similar chemical properties, is electrochemically inactive. We also fabricated the Mg3Bi2 thin film electrodes, which show reversibility with low overpotential not only in the acetonitrile solution but also glyme-based solutions. Surface layer corresponding to the decomposed TFSA anion is slightly suppressed in the case of the Mg3Bi2 thin film electrode, compared with Mg metal. Comparative study of hydrolysis process of the Mg3Bi2 and the Mg3Sb2 suggests that the both intermetallic anodes are not completely passivated. The bond valence sum mapping of the Mg3Bi2 indicates that the fast Mg2+ diffusion pathway between 2d tetrahedral sites is formed. The electrochemical properties of the Mg3Bi2 anode is mainly due to the less passivation surface with the fast Mg2+ diffusion pathways.
RESUMO
Reversible dendrite-free low-areal-capacity lithium metal electrodes have recently been revived, because of their pivotal role in developing beyond lithium ion batteries. However, there have been no reports of reversible dendrite-free high-areal-capacity lithium metal electrodes. Here we report on a strategy to realize unprecedented stable cycling of lithium electrodeposition/stripping with a highly desirable areal-capacity (12 mAh cm-2) and exceptional Coulombic efficiency (>99.98%) at high current densities (>5 mA cm-2) and ambient temperature using a diluted solvate ionic liquid. The essence of this strategy, that can drastically improve lithium electrodeposition kinetics by cyclic voltammetry premodulation, lies in the tailoring of the top solid-electrolyte interphase layer in a diluted solvate ionic liquid to facilitate a two-dimensional growth mode. We anticipate that this discovery could pave the way for developing reversible dendrite-free metal anodes for sustainable battery chemistries.
RESUMO
SCOPE: Garlic is used for both culinary and medicinal purposes by many cultures. The garlic organosulfur compounds (GOSCs) are thought to be bioactive components. This study aims to clarify the antiinflammatory effects and molecular mechanisms of GOSCs in both cell and animal models. METHODS AND RESULTS: RAW264.7 cells were treated with six kinds of GOSCs to screen their influence on cyclooxygenase-2 and inducible nitric oxide synthase expression by Western blotting. Prostaglandin E2 and nitrite were measured by ELISA and Griess reaction, respectively. Cytokines in culture medium were assayed by the multiplex technology. Proteins were detected by Western blotting. Mouse paw edema was induced by LPS. The results revealed that diallyl trisulfide (DATS) was a strongest inhibitor for cyclooxygenase and inducible nitric oxide synthase among GOSCs, and reduced the levels of LPS-induced IL-6, IL-10, IL-12(p70), KC, MCP-1, and TNF-α. Cellular signaling analysis revealed that DATS downregulated AKT1/TGF-ß-activated kinase-mediated mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. Furthermore, DATS activated Nrf2-mediated expression of HO-1 and NQO1 and reduced LPS-induced intracellular reactive oxygen species, which may contribute to suppress inflammatory mediator production. Finally, in vivo data demonstrated that DATS attenuated LPS-induced mouse paw edema. CONCLUSION: DATS as a potential inhibitor revealed antiinflammatory effect in both cell and animal models by downregulating AKT1/TGF-ß-activated kinase-mediated NFκB and MAPK signaling pathways.