Synthesis And Electrochemical Performance Of Low Dimensional Flexible Metal Oxide Nanocomposites

Lithium-ion batteries（LIBs）,a low-carbon non-polluting green energy storage device,have been widely used in portable electronic equipment,new energy vehicles and other fields due to its high energy density,long cycle life and no memory effect.In recent years,with the development of digital cameras,handheld computers,wearable electronic devices,lithium-ion batteries have been more widely concerned.As a crucial part of LIBs,the selection of the anode materials is of great significance to the overall properties.Currently commercial lithium-ion battery is insufficient to satisfy the future energy storage requirement,because of the low theoretical capacity(372 m A h g^-1)and non-bending.Metal oxides have received considerable attention because of their widespread potential applications in areas of new energy sources.And nanotechnology has been proved to have many advantages in lithium-ion battery anode material.So some efforts have been made to design and synthesis of low-dimensional flexible metal oxide nanocomposite materials.A variety of methods are used to analyze its composition and microstructure.In addition,to improve their poor cycle stability,to explore the anode material with long cycle life and high power density,as the anode material of lithium ion battery,their electrochemical properties have been studied.The main parts of the results are summarized as follows:（1）ZnO nanoparticles were synthesized on the carbon cloth by hydrothermal method,and then the Fe₂O₃ nanocomposite was obtained on the carbon cloth by using the nanometer array as the template and the subsequent heat treatment process.A series of characterization of the synthesized nanocomposites was carried out to explain their electrochemical properties from the microstructures.The carbon cloth can be used not only as a flexible substrate,but also for the volume change of the material.It is helpful to maintain the cycling stability of the material.The stability of the Fe₂O₃ nanocomposites on the carbon cloth was investigated.The results showed that the specific capacity of the Fe₂O₃ nanocomposites with low loading could reach 3000 m A h g^-1 at a current density of 1000 m A g^-1,The specific capacity of 1200 m A h g^-1 can be achieved even after 50 cycles of cycling.And the results show that the composite has good cycling stability.（2）CuGeO₃ nanorods were prepared by hydrothermal method.CuGeO₃@TiO₂ composites were prepared by combining the advantages of CuGeO₃ nanorods and TiO₂.The TiO₂ protective layer could suppress the volume expansion of CuGeO₃ nanorods and maintain the structural stability of the materials.In addition,CuGeO₃@TiO₂ exhibits good cyclic stability and rate performance due to the coordination effect between different components of the composite.At the current density of 200 m A g^-1,the capacity of CuGeO₃@TiO₂ electrode is always kept at 200 m A h g^-1,and its electrochemical stability over CuGeO₃ precursors.