Yii-Tay Chiou

Influence of the LiCoO2 particle size on the performance of lithium-ion batteries

Abstract Lithium cobalt oxide, LiCoO 2 , of different particle-size distributions, has been studied in the Li/LiCoO 2 rechargeable battery system. The particle size influences the cycle stability. Upon cycling, the voltage drop contributed to the ohmic and polarization of charge/discharge processes were evaluated by current interrupt method.

The study of carbon half-cell voltage in lithium-ion secondary batteries

The half-cell voltage of carbon is measured by a three-electrode technique. In this study, the effects of cathode/anode mass ratio and charging patterns on the carbon half-cell voltages are investigated by factorial experimental design. From the results of analysis-of-variance (ANOVA), the top voltage of charge and the cathode/anode mass ratio are the major factors which influence the minimum half-cell voltage of carbon during charge.

Development of microlens arrays for high-speed optical communication

In this study, polymeric microlens arrays, well suited for high-volume and low-cost production, were developed for efficiently coupling the light from vertical-cavity surface emitting lasers (VCSELs) to multi-mode fiber ribbon. They were fabricated by microinjection molding with Ni-electroplated mold insert. Modified LIGA processes and the Ni-electroplating are used to make the master and the metallic mold insert, respectively. In this study, microinjection molding with metallocene based cyclic olefin copolymer (mCOC) was chosen to replicate microlenses. Good surface profile and high dimensional accuracy are achieved. Coupling efficiency of 55 +/- 3 % with a working distance of 400 +/- 60 micrometer is obtained. To verify its applications on high-speed interconnections, we also designed the evaluated board and set up an opto-electronic measurement platform. The high-speed measurement shows that the electrical-to-optical conversion 3dB-bandwidth is above 1.8 GHz, and the eye diagram at 2.488 Gbps is acceptable for the SONET OC-48 eye mask.