Abstract: For lithium secondary microbattery anode, the tin oxide thin films with the various Si
additions (0, 2, 6, 10, 20mol%) were prepared on the p-type (100) SiO2/Si substrate by R.F. magnetron sputtering method at the substrate temperature of 300°C under the gas ratio of Ar/O2 (7/3). The effect of Si addition to the SnO2 thin film on the structural change and electrochemical performance and the reversible capacity performance was investigated. As Si addition amounts increased, Si-O bonding density increased and Sn-O bonding density decreased. The addition of
optimum Si amount led decrease of Sn oxidation state so that the irreversible capacity was reduced and cycle characteristic was enhanced during the charge-discharge test. SnO2 films with 6mol%Si had the highest reversible capacity of 700mAh/g after 100cycles.
Abstract: The effects of deformation on corrosion behavior of galvanized steel were investigated. Accelerated corrosion test was conducted under the conditions of 30oC and 90% relative humidity with flowing 200ppm sulfur dioxide gas for five weeks. Surface morphologies and corrosion products were analyzed by SEM/EDS and XRD. The corrosion products were composed of hydrates of ZnSO4. And corrosion rates of each part, bottom, bended and wall, were increased with
growing strain due to surface damage and enlargement of naked surface for corrosion.
Abstract: In this work, we made micromolds using SU-8 photoresist and adopted electroless Ni-P deposition, well known as a hard coating material, to improve the rigidity and durability of SU-8 micromolds. After a micromold using SU-8 was defined by conventional lithography, Ni-P layer was electrolessly deposited on SU-8. By means of electroless Ni-P deposition, it was possible to increase the hardness of a micromold as much as about 17 times. In addition, it will be able to make various sized micromolds with one photomask by regulating the thickness of Ni-P layer.
Abstract: LiNiVO4 was synthesized using Li2CO3, NH4VO3 and Ni(CH3COO)2.4H2O as starting reagents and citric acid as a chelating agent. Mole ratios of metals to citric acid used for the preparation were 1 : 1 - 1 : 4. Carboxylate precursors were calcined at high temperatures to form powder. TGA data showed weight loss due to the evaporation and decomposition processes. FTIR showed the stretching
bands of VO4 tetrahedron at 642, 713 and 813 cm-1. For 1 : 3 and 1 : 4 mole ratios, nano-crystals of inverse spinel LiNiVO4 (produced at 450 oC calcination for 6 h) were detected by XRD, electron diffraction, SEM and TEM.