The Research Of Preparation And Electrochemical Properties Of Fe/Co/Mn Metallic Oxide Nanomaterials

As the energy crisis and environmental pollution has become increasingly apparent, the development of green renewable new energy has become one of the hottest topics today. And lithium ion battery and super capacitor, due to their high working voltage, high specific capacity, large power density, long service life, low self-discharge rate, and pollution-free, has become one of the most important new energy storage equipment. Because the practical application of lithium ion battery and super capacitor largely depends on the electrode material, the design and synthesis of a safe and reliable, low cost, excellent performance of electrode materials has become the big challenges of between academic and technology. Compared with the traditional carbon-based materials, transition metal oxide nanomaterials as electrode materials for improving the reversible capacity and power density of electrode material provide a lot of possibilities. The performance of metal oxide nanomaterials largely depends on its structure characteristics, such as morphology, size and structure stability of the materials, etc. Therefore unified morphologies, structure stability of nanometer materials to a certain extent, improve the electrochemical performance of electrode materials.This paper mainly used the electrostatic spinning method and hydrothermal to synthesize morphology of manageable size, structure stability of metal oxide nanomaterials as electrode material, so as to realize the improvement of the performance of the lithium ion batteries and super capacitors. The main content summarized as follows:?1? We synthesized CoFe₂O₄/C nanofiber arrays by electrostatic spinning, the use of XRD, SEM and TEM technology to characterize the structure and micromorphology of the electrode materials. XRD results show the diffraction peak of synthetic CoFe₂O₄ nanometer fiber corresponding to the peak of standard CoFe₂O₄ ?JCPDDS 22-1086?. SEM and TEM images show that the synthetic CoFe₂O₄/C material has a one-dimensional solid structure, including the diameter of the fiber about 50-100 nm. With electrochemical testing methods, such as constant current charge and discharge, the capacitor performance were studied. Results show that the synthetic CoFe₂O₄/C nanometer fiber electrode showed excellent electrochemical performance, its initial single electrode specific capacitance of 0.82 F cm"2 and 4000 cycle after the discharge capacity of remaining at about 82% of the initial capacity. Studies have shown that CoFe₂O₄/C nanofibers is a more promising electrochemical capacitor electrode material.?2?CoFe₂O₄/C nanofibers electrode materials prepared by electrostatic spinning, were assembled into lithium ion battery for performance testing. By cyclic voltammetric curves, charge and discharge performance test, cyclic performance test, etc, performance tests on the electrochemical properties were analyzed. The experimental results show that the top 30 cycle of cycle performance is relatively stable, and the coulomb efficiency was close to 100%, when the current density is 100 mA g^-1, and voltage window is from 0.01 V to 3 V for cycle test 100 times. In addition, the first discharge specific capacity is about 973 mA g h-1. Studies have shown that CoFe₂O₄/C nanofibers is a certain potential prospects of lithium ion battery anode materials.?3? By electrostatic spinning method combined water thermal synthesis CoFe₂O₄/MnO₂/C nanotube arrays, XRD, SEM and TEM technology had been used to characterize the structure and micromorphology of the electrode materials. By cyclic voltammetric curves, charge and discharge performance test, cyclic performance test, etc, performance tests on the electrochemical properties were analyzed. Experimental results show that under the current density of 100 mA g^-1, CoFe₂O₄/MnO₂/C nanotubes showed a 1580.6mA g h-1 initial capacity and 250 cycle after still have a 713.6 mA g h-1 reversible capacity. Through the test on the properties of material ratio, we found that CoFe₂O₄/MnO₂/C nanotubes after large current charge and discharge, the charge and discharge recovery ability is stronger. These superior electrochemical properties of the material can be attributed to the structure characteristics of CoFe₂O₄/MnO₂/C nanotubes. Studies have shown that CoFe₂O₄/MnO₂/C material is a kind of very potential lithium ion battery cathode materials.