| Summary: | 碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 105 === In recent years, many scientists have been searching for other metal-ion batteries to replace lithium-ion batteries. Among them, magnesium ion batteries have the opportunity to become the new generation of secondary batteries. Magnesium ion battery has higher theoretical volumetric capacity and are safer than lithium-ion battery. In this study, we synthesized layered VOx nanotubes with micron-size length and an average diameter of 154 nm as the cathode. The 0.25 M APC was employed as the electrolyte and was added with 0.5 M LiCl/NaCl/MgCl2. The cells were then charged and discharged galvanostatically at 50 mA g-1 between 2.6 and 0 V (vs.Mg2+/Mg). The first discharge capacities of APC and LiCl/NaCl added APC were 285/309/354 mA h g-1, respectively. The fifth discharge capacities reached 81/163/168 mA h g-1, respectively. We further tested of VOx prepared cathodes using low (LT-VOx) and high (HT-VOx) octadecylamine concentration in 0.5 M NaCl added 0.25 M APC electrolyte. The cells were charged and discharged galvanostatically at 100 mA g-1. After 30 cycles, the discharge capacities of LT-VOx and HT-VOx achieve 68.47/88.61 mA h g-1, respectively. The EDS analyses show that the magnesium strips and deposits at the cathode with charging and discharging, and the surface morphology of VOx does not change significantly during the cycles. The LiCl/NaCl/MgCl2 added APC electrolytes all improve the stability of magnesium and increase current density of the cells. The NaCl added APC electrolyte gives rise to the optimal electrical characteristics among the magnesium ion batteries tested.
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