The troubadour Marcabru and his public

Vanadium(V)-containing oxides show superior intercalation properties for alkaline ions, although the performance of the material strongly depends on its surface morphology. In this work, intercalation activity of LiV$_{3}$O$_{8}$, prepared by a conventional solid state synthesis, is demonstrated for the first time in non-aqueous Li,Na-ion hybrid batteries with Na as negative electrode, and different Na/Li ratios in the electrolyte. In the pure Na-ion cell, one Na per formula unit of LiV$_{3}$O$_{8}$ can be reversibly inserted at room temperature via a two-step process, while further intercalation leads to gradual amorphisation of the material, with a specific capacity of 190 mAhg$^{−1}$ after 10 cycles in the potential window of 0.8–3.4 V. Hybrid Li,Na-ion batteries feature simultaneous intercalation of Li$^+$ and Na$^+$ cations into LiV$_{3}$O$_{8}$, resulting in the formation of a second phase. Depending on the electrolyte composition, this second phase bears structural similarities either to Li$_{0.7}$Na$_{0.7}$V$_{3}$O$_{8}$ in Na-rich electrolytes, or to LiV$_{3}$O$_{8}$ in Li-rich electrolytes. The chemical diffusion coefficients of Na+ and Li+ in crystalline LiV$_{3}$O$_{8}$ are very close, hence explaining the co-intercalation of these cations. As DFT calculations show, once formed, the Li$_{0.7}$Na$_{0.7}$V$_{3}$O$_{8}$-type structure favors intercalation of Na$^+$, whereas the LiV$_{3}$O$_{8}$-type prefers to accommodate Li$^+$ cations

Anomalous electric conductions in KSbO3-type metallic rhenium oxides

Single crystals of KSbO3-type rhenium oxides, La4Re6O$19, Pb6Re6O19, Sr2Re3O9 and Bi3Re3O11, were synthesized by a hydrothermal method. Their crystal structures can be regarded as a network of three-dimensional orthogonal-dimer lattice of edge-shared ReO6 octahedra. All of them exhibit small magnitude of Pauli paramagnetism, indicating metallic electronic states without strong electron correlations. The resistivity of these rhenates, except Bi3Re3O11, have a temperature dependence of$rho(T)=\rho_{0}+AT^{n}$$(n \approx 1.6)$ in a wide temperature range between 5 K and 300 K, which is extraordinary for three-dimensional metals without strong electron correlations. The resistivity of Bi3Re3O11 shows an anomaly around at 50 K, where the magnetic susceptibility also detects a deviation from ordinary Pauli paramagnetism.Comment: 13 pages, 7 figures. J. Phys. Soc. Japan, in pres

Exploring the Ni redox activity in polyanionic compounds as conceivable high potential cathodes for Na rechargeable batteries

Although nickel-based polyanionic compounds are expected to exhibit a high operating voltage for batteries based on the Ni2+/3+ redox couple activity, some rare experimental studies on the electrochemical performance of these materials are reported, resulting from the poor kinetics of the bulk materials in both Li and Na nonaqueous systems. Herein, the electrochemical activity of the Ni2+/3+ redox couple in the mixed-polyanionic framework Na4Ni3(PO4)2(P2O7) is reported for the first time. This novel material exhibits a remarkably high operating voltage when cycled in sodium cells in both carbonate- and ionic liquid-based electrolytes. The application of a carbon coating and the use of an ionic liquid-based electrolyte enable the reversible sodium ion (de-)insertion in the host structure accompanied by the redox activity of Ni2+/3+ at operating voltages as high as 4.8 V vs Na/Na+. These results present the realization of Ni-based mixed polyanionic compounds with improved electrochemical activity and pave the way for the discovery of new Na-based high potential cathode materials

Study of the different synthesis routes on Li extraction-insertion of LiCoPO4LiCoPO_4

The electrochemical performance of LiCoPO4-based electrodes was studied in dependence on synthetic conditions. The role of particle size distribution is illustrated. Structural changes occurring at lithium extraction–insertion were explored by ex situ and in situ synchrotron XRD measurements. For the samples annealed at temperature lower than 600 °C the amorphisation of the cathode material was identified. For a high-temperature sample the two-phase character of electrochemical reaction was confirmed. The character of structural changes observed at charge and discharge is different: the two-phase reaction LiCoPO4–“CoPO4” occurs during charging, while discharge induces a strong increase of the cell volume for the Li-poor phase

Synchrotron diffraction study of lithium extraction from LiMn0.6Fe0.4PO4LiMn_{0.6}Fe_{0.4}PO_4

This open-label extension evaluated the long-term efficacy and tolerability of rufinamide in patients with Lennox-Gastaut syndrome (LGS) who had previously completed a 12-week double-blind study.In total, 124 patients (aged 4-37 years), receiving 1-3 concomitant antiepileptic drugs, were treated with rufinamide approximately 25-60 mg/kg/day. Efficacy was assessed by seizure frequency; tolerability by adverse events (AEs) and laboratory tests.Overall, patients were treated with rufinamide for a median (range) of 432 (10-1149) days. Reductions in seizure frequency were observed throughout the study; during the last 12 months of treatment, 41.0% and 47.9% of patients had > or = 50% reduction in total and tonic-atonic seizure frequency, respectively. The most common AEs were vomiting (30.6%) and pyrexia (25.8%).In this open-label extension, rufinamide appeared to be an effective long-term adjunctive therapy for the treatment of LGS-associated seizures in children and young adults