A rGO-Based Fe2O3 and Mn3O4 binary crystals nanocomposite additive for high performance Li–S battery

A Novel Approach of Sea Urchin-like Fe-Doped Co3O4 Microspheres for Li-S Battery Enables High Energy Density and Long-Lasting

The poor cycle stability caused by the shuttle effect of polysulfides which have been key scientific issue in the development of high-efficiency lithium-sulfur (Li-S) batteries. In this work, the authors report a Fe-doped Co₃O₄ (named FCO) that was used as a sulfur-loaded host material for Li-S batteries. We demonstrate the important roles of well-designed Co₃O₄ particles and Fe atoms in regulating polysulfide conversion due to the strong adsorption of polysulfides by polar Co₃O₄, whereas Fe atoms and Co₃O₄ catalyze polysulfide conversion. Therefore, the LiS batteries with FCO-180 (When the hydrothermal temperature is 180 °C) sea urchinlike composites exhibited a high superior energy density (992.7 mAh g^-1 at 0.2 C, after 100 cycles) and long-term cyclability (649.4 mAh g^-1 at 1 C, 300 cycles) with high sulfur loading (75 wt%). This work confirms that the FCO-180 sea urchinlike increases not only the capacity of high-rate but also a generic and feasible strategy to construct practical Li-S batteries for emerging energy-storage applications.

Synthesis and Characterization of Nanocrystalline Ba-doped Mn3O4 Hausmannite Thin Films for Optoelectronic Applications

In the present work, nanocrystalline hausmannite Mn3O4:Ba thin films have been deposited on glass substrates by chemical spray pyrolysis (CSP). Then, we investigated the impact of Ba doping concentrations on the structural, morphological and optical properties. The structural characteristics were investigated by X-ray diffraction technique and clearly show the films have a spinel Mn3O4 polycrystalline structure, the degree of crystallinity was improved by increasing Ba concentrations in Mn3O4 matrix with crystallite size range of 15–33[Formula: see text]nm. The lattice parameters, the unit cell volume and the (Mn-O) bond length of tetrahedral and octahedral sites, were varied by increasing Ba concentrations. SEM micrographs show that the films are homogeneous with nanoparticles dispersed on the surface with sizes range 30–132[Formula: see text]nm. The optical properties were estimated by UV-Vis-NIR spectrophotometer and exhibited that the optical transmittance and band gap were improved by increasing Ba doping concentration. Empirical equations were suggested to estimate some correlated variables with excellent agreement with the experimental data. The optimum condition was recorded in films doped with 3% of Ba where a better crystallinity, a preferable surface morphology and outstanding optical properties have been achieved.