Papers by Author: Wei Ping Chen

Abstract: Al and Sb codoped ZnO thin films were prepared through a sol-gel spin coating method on glass substrates and annealed in different atmospheres. The XRD results show that the films have hexagonal wurtzite ZnO structure and SEM results reveal that the films annealed in hydrogen consist of hexagonal nanorods with diameters of 84 nm and lengths of 422 nm, however the films annealed in other atmospheres without nanorods. The photoluminescence (PL) spectrum shows that the emission peaks of the films are mostly at 390 and 460 nm, and the film annealed in hydrogen has the strongest intensity of peak at 390 nm and the film annealed in air has the strongest intensity of peak at 460 nm. The electrical properties show that the films annealed in hydrogen have a lowest resistivity of 1.02×10-3 Ω•cm.

Abstract: CoO was usually added to the positive electrodes of MH/Ni batteries as the conductive agent. In this paper, well crystallized multi-walled carbon nanotubes (CNTs) with diameter about 10 nm were added to the positive electrodes of MH/Ni batteries together with CoO. During the process of transformation from CoO to CoOOH, a complex conductive network was created with CNTs as the frame. Because of the high conductivity and the excellent tension characteristics of CNTs, the charge-transfer capability of the electrode was improved and the integrality of the complex conductive network was enhanced. The electrochemical measurements indicated that the impedance of the electrode with CNT-CoO complex conductive agent was lessened compared to the electrode with simple CoO agent. Performance tests of the sealed batteries showed that the positive electrodes with CNT-CoO complex conductive agent exhibited higher discharge voltage, improved capacity, modified discharge stability and prolonged lifespan, especially at high current rates.