The Electrode Preparation Of The Graphene/Carbon Nanotube 3D Composites And The Application In Energy Storage

Graphene and carbon nanotubes are very typical representatives of carbonmaterials. Because of their high specific surface area and excellent electricalconductivity,they have a very wide range of applications in many fields. Among graphene/carbon nanotubes composite material,has been attracting great interest because of its synergistic effect and well 3D net structure.A novel the ultrasonic mixed graphene and carbon nanotubes is reported to prepare graphene/carbon nanotubes composite material,and as the storage device(super capacitor and lithium ion battery).The main content includes the following several aspects:1.Modified Hummers method is used to change the starting materials 8000 mesh graphite powder preparation of graphite oxide ethanol suspension, after weighing the quality of different single-walled carbon nanotubes with the preparation of good graphite oxide ultrasonic mixing in the ultrasonic processor, preparation of three kinds of different mass ratio of graphene oxide/carbon nanotube composite materials.Then the graphene oxide/carbon nanotubes films were produced by electro-spray deposition of a graphene oxide colloidal solution onto a substrate.Eventually,the graphene/carbon nanotubes films used in the study were performed used a convection oven irradiate the graphene oxide/carbon nanotubes films 10 minutes. The three kinds of different mass ratio of graphene/carbon nanotubes were characterized by TG,IR,XRD,XPS,BET,SEM and TEM. The results show that three kinds of different mass ratio of graphene/carbon nanotube composite materials, the RGO/CNTs-10% is the best quality, it can form good 3 D net conductive structure and synergistic effect.2.The stainless steel sheets are used as substrate in the electro-spray of three kinds of different graphene oxide/carbon nanotubes colloidal solution.Then they are irradiated 10 minutes in convection oven form three kinds of different graphene/carbon nanotubes films.Eventually,the three kinds of different mass ratio of graphene/carbon nanotubes films as the electrode are assembled into the supercapacitor.The electrochemical properties of three kinds of different mass ratio graphene/carbon nanotubes as electrode materials were examined by cyclic voltammetry,galcanostatic charge- discharge and electrochemical impedance.The results indicated that among the three kinds of composite materials, the RGO/CNTs-10% as super capacitorelectrode showed a excellent electrochemical performance, its specific capacity value can reach 390.4 F/g at 0.2 A/g, its specific capacity value still can reach 101.6 F/g at40.0 A/g, and its specific capacity value after a ten thousand-cycle remained at more than 90% of the capacity is maintained at 1.0 A/g.3.The copper foil are used as substrate in the electro-spray of three kinds of different graphene oxide/carbon nanotubes colloidal solution.Then they are irradiated10 minutes in convection oven form three kinds of different graphene/carbon nanotubes films.Eventually,the three kinds of different mass ratio of graphene/carbon nanotubes films as the negative electrode are assembled into the lithium ion battery.The electrochemical properties of three kinds of different mass ratio graphene/carbon nanotubes as the negative electrode materials of lithium ion battery were examined by cyclic voltammetry, galcanostatic charge-discharge and electrochemical impedance. The results indicated that the three kinds of composite materials, the RGO/CNTs-10% as lithium ion battery cathode showed excellent electrochemical performance, under the 1C(current density of 0.372A/g)the discharge specific capacity value can reach 1386.9 mAh/g, after convertible(five C, tenC,twentyC, fortyC, one hundredC) after repeated cycle back to 1 C in the discharge specific capacity value still can reach 1230.3 mAh/g, when after 20 C in circular one thousand times, its discharge specific capacity remains can reach 90.4%.