NiO-based Nanomaterials Prepared By Electrospinning And Their Electrochemical Properties

Lithium ion battery has become one kind of the most important secondary batteries because of its high energy density, high voltage, low self-discharge, no memory effect, long cycle life and environmental friendliness. Therefore, research on improving the performance of the lithium ion batteries, such as energy density, power density, rate capability and safety, becomes a hot topic in recent years.Transition metal oxides with theoretical capacities for2-3times of the commercially available anode material, are promising materials for next-generation high-performance lithium ion battery anodes. NiO-based nanomaterials were studied in this thesis, and NiO-based nanofibers and nanotubes were prepared by the electrospinning method. Metal particles or some other metal oxides were doped to the NiO-based materials to improve structural stability and electrical conductivity, which led to the improvement of cycling performance and rate capability of the materials.The main contents and results are listed below:NiO nanofibers and Au-doped NiO nanobelts are prepared by the electrospinning method. Lithium storage properties of NiO nanofibers and Au-doped NiO namobelts as lithium-ion battery anodes are investigated. Experimental results show that the Au-doped NiO nanobelts electrode has good cycling stability. After charging and discharging for35cycles, it still remains a discharge capacity of about685mA h g-1Ag-doped NiO nanotubes are also prepared by electrospinning. When the material is used as an electrode of LIBs, a high coulombic efficiency of first cycle is obtained. Especially, it has a good cycling stability. After charging and discharging for100cycles, it still remains a discharge capacity of about741mA h g-1Porous NiO-ZnO composite nanofibers with high capacity, good cycling stability and excellent rate capability are prepared by electrospinning method. It is found that, after being composited with ZnO, the NiO-ZnO composites as anode materials exhibits better electrochemical performance than NiO materials. After charging and discharging for120cycles, the composites electrode still has high specific capacities (the discharge capacity is about949mA h g-1), superior cycling stability, and rate stability. Even after charging and discharging at high rates, the electrode still retains high discharge capacity and excellent cycling stability.