Preparation And Electrochemical Performance Investigation Of One-dimensional Transition Metal Oxide Nanomaterials

Recently,lithium ion batteries?LIBs?have dominated the market for cell phones,laptops,and several other portable electronic devices for many years.In order to match the necessity of increasing need for higher energy density storage devices,for example,hybrid/electric vehicles.Higher energy density lithium ion batteries have to be investigated.As one of the most important components of in LIBs,anode materials have been intensively studied.Numerous studies have demonstrated that transition metal oxides,for example,the titanium dioxide,cobaltosic oxide and cobalt oxide have higher specific theoretical capacity.When used as anode materials,they can show excellent electrochemical performance.Based above the account,the transition metal oxides have been selected as the main research content of this paper,the transition metal oxides nanocomposites have been synthesized by electrospinning combined with post processing,and the electrochemical properties of the nanocomposites have been tested.The detailed information of experiment and research has been listed as following:1.One-dimensional TiO₂ nanofibers have been synthesized by electrospinning combined with the sintering process.The nanofibers were compounded with GO due to the electrostatic adsorption force.The G/TiO₂ composite nanofibers have been obtained after the reduction process.The as-prepared samples were characterized by thermogravimetric and differential scanning calorimetry?TG-DSC?,microscopic raman spectrometer,X-ray diffraction?XRD?,scanning electron microscope?SEM?and transmission electron microscope?TEM?and brunauer-emmett-teller?BET?analysis.After the calcination process,the diameter of the 1D TiO₂ nanofibers is about 200 nm.The electrochemical test results show that the G/TiO₂ composite nanofibers have higher reversible charge/discharge capacity,improved cycling stability and excellent high-rate performance.This is mainly attributed to the synergistic effect between G and TiO₂ nanofibers.2.One-dimensional Co₃O₄ porous nanotubes have been synthesized by theelectrospinning combined with the sintering process.The porous nanotubes were compounded with GO due to the electrostatic adsorption force.The G/Co₃O₄composite nanotubes have been obtained after the reduction process.The porous Co₃O₄ nanotubes were obtained after sintering at 600°C for 2 h,and the pipe diameter is about 200 nm.The porous distribute uniformly on the surface of the nanotubes.The as-prepared G/Co₃O₄ composite nanotubes were characterized by thermogravimetric?TG?,X-ray diffraction?XRD?,fourier transform infrared spectroscope?FT-IR?,microscopic raman spectrometer,scanning electron microscope?SEM?and transmission electron microscope?TEM?and X-ray photoelectron spectroscopy?XPS?.The electrochemical properties test results proved that the G/Co₃O₄ composite nanotubes possessed of stable charge/discharge capacity and excellent rate performance.The improved electrochemical performance could be caused by the synergistic effects and the unique morphology of porous nanotube.3.One-dimensional Co/CoO hierarchical composite nanofibers have been prepared by electrospinning combined with the sintering process.The diameter of the nanofibers is about 200 nm,and the diameter distribute uniformly.The metallic elemental cobalt with the morphology of prod have a distribution on the surface of nanofibers.The composite nanofibers have the three-dimensional morphology owing to the existence of Co.The final products were tested by thermogravimetric?TG?,X-ray diffraction?XRD?,scanning electron microscope?SEM?and transmission electron microscope?TEM?and X-ray photoelectron spectroscopy?XPS?.The composite nanofibers were applied as anode materials for LIBs and shown outstanding high rate cycle performance and rate performance.This can be attributed to unique one-dimensional and three-dimensional morphology and metal elemental Co with excellent electrical performance.