Sirong Li

Self-assembly and embedding of nanoparticles by in situ reduced graphene for preparation of a 3D graphene/nanoparticle aerogel.

A 3D graphene architecture can be prepared via an in situ self-assembly of graphene prepared by a mild chemical reduction. Fe(3) O(4) nanoparticles are homogeneously dispersed into graphene oxide (GO) aqueous suspension and a 3D magnetic graphene/Fe(3) O(4) aerogel is prepared during the reduction of GO to graphene. This provides a general method to prepare 3D graphene/nanoparticle composites for a wide range of applications including catalysis and energy conversion.

Three-dimensional porous V2O5 cathode with ultra high rate capability

Three-dimensional (3D) porous vanadium pentoxide (V2O5) thin films were synthesized by electrostatic spray deposition followed by annealing at 350 °C in air. The interconnected pore networks facilitate the kinetics of lithium-ion diffusion and help the porous V2O5 with stable capacity, high energy efficiency and excellent rate capability as a cathode material for lithium batteries.

Efficient preparation of highly hydrogenated graphene and its application as a high-performance anode material for lithium ion batteries

A novel method has been developed to prepare hydrogenated graphene (HG) via a direct synchronized reduction and hydrogenation of graphene oxide (GO) in an aqueous suspension under (60)Co gamma ray irradiation at room temperature. GO can be reduced by the aqueous electrons (e(aq)(-)) while the hydrogenation takes place due to the hydrogen radicals formed in situ under irradiation. The maximum hydrogen content of the as-prepared highly hydrogenated graphene (HHG) is found to be 5.27 wt% with H/C = 0.76. The yield of the target product is on the gram scale. The as-prepared HHG also shows high performance as an anode material for lithium ion batteries.

Synthesis and electrochemical properties of high performance yolk-structured LiMn2O4 microspheres for lithium ion batteries

Yolk-structured microspheres of spinel LiMn2O4 are successfully prepared by a specially designed multi-step synthesis procedure involving precipitation, controlled oxidation, selective etching and chemical lithiation. Solid-structured and hollow-structured LiMn2O4 are also synthesized by a similar method for comparison. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller method and IR spectroscopy are employed to study their structures and compositions. The electrochemical properties of the LiMn2O4/Li cells are also tested. The results indicate that LiMn2O4 powder composed of yolk-structured microspheres possesses remarkable high rate capability and outstanding high capacity retention not only at room temperature but also at elevated temperatures. This study may provide significant new insight into restraining the capacity fading of LiMn2O4 electrodes and the yolk-structured LiMn2O4 may be used for the next generation of lithium ion batteries.

Synthesis of Ag2Se by sonochemical reaction of Se with AgNO3 in non-aqueous solvent

Abstract Ultrafine Ag 2 Se powders were synthesized by a sonochemical reaction between AgNO 3 and Se in ethylenediamine under ambient conditions. The samples were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM), and differential scanning calorimetry (DSC). XRD patterns showed that the low-temperature β-phase Ag 2 Se was obtained. TEM images indicated a flake-like shape for the Ag 2 Se particles. By the sonochemical process, the composition of as-obtained product was in control. The influence of ultrasound and solvent is discussed.