Ying-ke Zhou

Lithium Insertion into TiO2 Nanotube Prepared by the Hydrothermal Process

A TiO 2 nanotube was prepared by a hydrothermal process. Transmission electron microscope tests showed that the products are uniform straight hollow tubes with the diam around 8 nm and the length over 300 nm. X-ray diffraction measurements indicate that the nanotubes crystallized in anatase TiO 2 . Cyclic voltammetry and galvanostatic charging and discharging tests showed that lithium-ion intercalation/deintercalation occured reversibly in the TiO 2 nanotube electrode, and a high capacity can be obtained. Electrochemical impedance spectra show that Li + ion intercalation occurs below 2.2 V. Around the 1.7 V plateau, the total electrochemical resistance reached a minimum.

Preparation and Electrochemistry of SWNT/PANI Composite Films for Electrochemical Capacitors

Single-walled carbon nanotube/polyaniline (SWNT/PANI) composite films were prepared by in situ electrochemical polymerization of an aniline solution containing different SWNT contents. Surface morphology and structural properties of these PANI-based films were examined by a scanning electron microscope and X-ray photoelectron spectroscopy. The electrochemical capacitance properties of these films were investigated with cyclic voltammetry, charge-discharge tests, and ac impedance spectroscopy. The composite film, based on the charge-transfer complex between well-dispersed SWNT and PANI matrixes, shows much higher specific capacitance, better power characteristics, and is more promising for applications in capacitors than a pure PANI film electrode.

Synthesis of high-ordered LiCoO2 nanowire arrays by AAO template

Abstract LiCoO 2 nanowire arrays were prepared using porous anodic aluminum oxide (AAO) template from sol–gel solution containing Li(OAc) and Co(OAc) 2 . Electron microscope results showed that LiCoO 2 nanowires of uniform length and diameter were obtained. X-ray diffraction and electron diffraction pattern investigations demonstrate that LiCoO 2 nanowires are a layered structure of LiCoO 2 crystal.

Synthesis of high-ordered LiMn2O4 nanowire arrays by AAO template and its structural properties

LiMnO2 nanowire arrays were prepared using a porous anodic aluminum oxide (AAO) template from a sol–gel solution containing Li(OAc) and Mn(OAc)2. Electron-microscope results showed that a uniform length and diameter of LiMnO2 nanowires were obtained, and the length and diameter of the LiMnO2 nanowires are dependent on the pore diameter and the thickness of the applied AAO template. X-ray diffraction and electron diffraction pattern investigations demonstrate that LiMnO2 nanowires are a layered structure of LiMnO2 crystal. X-ray photoelectron spectroscopy analysis indicates that a material closely resembling stoichiometric layered LiMnO2 has been obtained.

Synthesis of highly ordered LiNiO2 nanowire arrays in AAO templates and their structural properties

Abstract LiNiO 2 nanowire arrays were prepared with porous anodic aluminum oxide (AAO) templates from sol–gel solution containing Li(OAc) and Ni(OAc) 2 . Electron microscope results showed that uniform length and diameter of LiNiO 2 nanowires were obtained, and the length and diameter of the LiNiO 2 nanowires are dependent on the pore diameter and the thickness of the applied AAO template. X-ray diffraction (XRD) and electron diffraction investigations demonstrate that the LiNiO 2 nanowires have the layered structure of LiNiO 2 . X-ray photoelectron spectroscopy (XPS) analysis indicates that a nearly stoichiometric layered LiNiO 2 material has been obtained.