The Synthesis Of Oxide (Sulphide) Carbon Fiber Composites And Lithium Storage Properies

In recent years, people’s need for energy is increasing with the development of economy and the progress of society. Because of the advantages including small volume, light weight, good cyclic performance and wide working voltage, lithium batteries (LIBs) were concerned. However, the energy density and power density of LIBs couldn’t meet the need of human, which limited the wide application to same extent. Therefore, the conductive substrate was used to grow nanomaterial, which is one of the effective methods. The hydrothermal methods were used to prepare different oxides or sulfides. The lithium ion batteries anode advantages of different oxides or sulfides on carbon fibers are researched. Research content are as follows:(1) The NiCo2O4 nanowires on carbon fibers were successfully synthesized via hydrothermal method and following treatment. As popular anodes for lithium ion batteries, NiCo2O4/carbon fiber nanocomposite showed high capacity and good cyclic stability, which delivered the capacity of 913 mA h g-1 at the current density of 200 mA g-1 after 53 cycles. The NiCo2O4/carbon fiber nanocomposite possessed higher specific capacity.(2) The Ni-Co LDH nanoneedles on the carbon fibers were successfully synthesized by solvent method. After treatment, the NiO-CoO/carbon fiber nanobrushes were obtained. The possible growth mechanism of NiO-CoO on carbon fibers was deeply studied. As anodes for lithium ion batteries, the NiO-CoO/carbon fiber nanobrushes showed the excellent electrochemical performance. The reversible capacity of the NiO-CoO/carbon fiber nanobrushes was 692 mA h g-1. Even after 200 cycles, the discharge capacity of 801 mA h g-1 was still delivered at the current density of 200 mA g’1. The electrode showed the good rate capability, which may ascribe to the special nanostructure of NiO-CoO/carbon fiber nanobrushes and good conductivity network of the carbon fibers. At the same time, NiO-CoO nanoneedle which directly grown on the surface of carbon fiber could avoid agglomeration and volume change. The nanoscale electrode short the ion distance. The excellent electrochemical performance of NiO-CoO/carbon fiber nanobrushes is attributed to the multiple effect.(3) Through a simple hydrothermal methods, the MoS2 nanosheets were prepared on the carbon fibers. In order to study the electrochemical performance ofMoS2/carbon fiber nanocomposite, it was used as lithium ion batteries anodes. It delivered the capacity of 743.43 mA h g-1. After 300 cycles, the MoS2/carbon fiber nanocomposite kept about 68.54% at 200 mA g’1, which indicated the good cyclic stability and rate capability. Therefore, it was an ideal cathode material for lithium ion batteries.