Preparation And Electrochemical Properties Of Graphene Based Multi-Composites

As a new generation of high-energy portable power, lithium-ion batteries have a high energy density, long life, safety, pollution, etc., has been widely used in the new energy vehicles, power grid, communications base stations, and other fields.However, at this stage electrode materials are lithium-ion battery development bottleneck.New carbon material graphene with ultra-high electrical conductivity, large surface area and stable mechanical properties has become a hot topic of lithium-ion battery anode materials, and graphene matrix composite constructed of a porous material having more excellent properties.Graphene has a strong mechanical strength, and therefore a high strength structure consisting of a porous, alleviate the tensile properties of the compression of the porous structure;Further, the porous material of the electrolyte channel helps infiltration, and excellent electrical conductivity of graphene also more conducive to transport and charge transfer;Furthermore, graphene excellent chemical and thermal stability of the porous material can withstand the impact of harsh environments.Titanium dioxide has a high voltage, low cost, environmentally friendly and extracting lithium in the process of change in the volume is small and other advantages, is considered a potential candidate alternative carbon-based materials for lithium-ion battery anode material; However, the disadvantage of low electrical conductivity of titanium dioxide, so as electrode material use is limited. In this paper, graphene-based materials for the study, the method of in-situ growth and build titania nanoparticles on its surface, and then by hydrothermal method of constructing a three-dimensional porous structure, designed and synthesized a series of high-performance graphene-based lithium-ion battery anode material, contents are as follows:(1) Through a simple, gentle way to grow TiO2 nanoparticles in situ on the surface of GO, then self-assembly formed by hydrothermal three-dimensional porous skeletal structure to give a three-dimensional porous graphene nano-TiO2 composite particle loading of the skeleton.(2) To further improve the TiO2/GFs performance as a lithium anode material, we used in situ polymerization method, the introduction of conductive polymers:polyaniline.We used two different methods:? first in graphene oxide surface polymerization of aniline, then hydrothermally grown metal oxide while reducing graphene oxide to obtain three yuan hybrid composites.? Also first in the graphene oxide surface polymerization of aniline and 80? slow long metal oxides, and finally reducing graphene oxide by hydrothermal give a two-dimensional three yuan hybrid nano-sheet material.(3) We further introduced into the conductive polymer polyethyleneimine (PEI), polyethylene imine-graphene oxide as a substrate to grow TiO2, to construct two dimensional ternary hybrid material. First and then the graphene oxide and polyethyleneimine were mixed and then 80? slow long metal oxides, and finally by hydrothermal reduction of graphene oxide to obtain a two-dimensional three yuan hybrid nano-sheet material.