Fast polysulfide catalytic conversion and self-repairing ability for high loading lithium-sulfur batteries using a permselective coating layer modified separator.

Li-S batteries are considered as one of the most promising battery systems because of their large theoretical capacity and high energy density. However, the "shuttle effect" of soluble polysulfides and sluggish electrochemical redox kinetics of Li-S batteries could cause a broken electrode structure and poor electrochemical performance. Herein, a high-performance and stable Li-S battery has been demonstrated by employing organo-polysulfide chain modified acetylene black (ABPS) as the coating layer on the separator.

Electrocaloric Effect of (KNa)NbO₃ Single Crystal.

The electrocaloric effect of (KNa)NbO₃ single crystal is calculated based on Landau-Devonshire theory. The electrocaloric coefficient and adiabatic temperature change are calculated with the variation of temperature in rhombohedral, orthorhombic and tetragonal phase. A maximum of electrocaloric coefficient is obtained in each ferroelectric phase.

Electrocaloric Effect of (110) Oriented KNbO₃ Film.

The room temperature electrocaloric effect is researched for (110) oriented KNbO₃ film based on Landau-Devonshire theory. The phase map with different ferroelectric states is built at room temperature with the considerations of thermodynamic equilibrium conditions and minimum of thermodynamic potential. Five ferroelectric structural phases are obtained theoretically.

Improved Photovoltaic Effect of Structured BiFeO₃ Film Deposited by Radio-Frequency Magnetron Sputtering.

Pure phase polycrystalline BiFeO₃ film was deposited onto FTO substrate by RF magnetron sputtering method. SEM result shows that BiFeO₃ film has the obvious porosity and large clusters which lead to the poor ferroelectric and photovoltaic properties in FTO/BiFeO₃/Ag device. However, these properties are improved in structured FTO/TiO₂/BiFeO₃/HTM/Ag device by incorporating the electron and hole transport materials.

Photovoltaic Effect in BiFeO₃ Film Deposited by RF Magnetron Sputtering.

A polycrystalline BiFeO₃ film was deposited on ITO substrate by RF magnetron sputtering method. Small crystallite size and compact structure are obtained for BiFeO₃ film which has the excellent ferroelectric properties. The measured photovoltaic response reveals an open-circuit voltage of ~0.

Raman enhancement by graphene-Ga2O3 2D bilayer film.

2D β-Ga2O3 flakes on a continuous 2D graphene film were prepared by a one-step chemical vapor deposition on liquid gallium surface. The composite was characterized by optical microscopy, scanning electron microscopy, Raman spectroscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy (XPS). The experimental results indicate that Ga2O3 flakes grew on the surface of graphene film during the cooling process.

Geometry and stability of Cu(n)N (n=1-6) and Cu(3n)N(n) (n=1-5) clusters.

The gradient-corrected density functional calculation is applied to search the lowest-energy configurations of Cu(n)N (n=1-6) clusters and the calculation indicated that Cu(3)N cluster is the most stable one. Based on the result, we further investigate the equilibrium geometries and stabilities of the Cu(3n)N(n) (n=2-5) clusters. We found that in Cu(6)N(2) cluster, N atoms formed a separate N(2) molecule away from the other part of the cluster.