Dissertation > Excellent graduate degree dissertation topics show

Synthesis and Electrochemical Properties of New Type Carbon Materials and Carbon-based Composites

Author: QiuLan
Tutor: CaoJieMing
School: Nanjing University of Aeronautics and Astronautics
Course: Physical and chemical
Keywords: reducted graphene oxide functionalized graphene sheets mesoporous carbon nanotubes metal oxide composite material lithium ion battery
CLC: TM912
Type: Master's thesis
Year: 2013
Downloads: 20
Quote: 0
Read: Download Dissertation

Abstract


Lithium-ion batteries are considered as the most promising power storage device because of theirhigh potential, long cycle life, environmental friendliness. The commercialized graphite materialsexhibit good cycling performance, but their low specific capacity can’t satisfy the demand for thedensity of batteries. It is urgent to research and explore new type graphite materials. The transitionmetal oxides exhibit high specific capacity, but the cycle performance and rate performance is verypoor. The nanocomposite material of carbon materials/metal oxide have been searching to improvethe performance of the lithium battery material. In this thesis, new carbon materials have beensynthesized successfully, using different chemical methods to prepare RGO-CNTs-Co3O4,C-Co3O4-FGS and MCNTs-Fe2O3composite materials, and the electrochemical performances of thesamples have been tested.RGO-CNTs-Co3O4ternary nanocomposite was synthesized using low temperature hydrothermalreaction and low temperature treatment method. In this typical experiment, with hydrazine as reducingagent, graphene oxide was reduced to graphene. At the same time, cobalt hydroxide was obtained onthe surface of RGO and CNTs. After treating at a low temperature, RGO-CNTs-Co3O4ternarynanocomposite was obtained. The results of electrochemical tests show the three element compositematerial the first discharge capacity is about1650mA·h/g at a current density of100mA·h/g, itsspecific capacity was maintained at1261mA·h/g, capacity retention rate is76.4%after50charge-discharge cycles.Carbon-coated cobalt oxide and graphene composite material was prepared via a hydrothermalsynthesis method. The morphologies and crystal structures of samples were characterized by SEM、TEM and XRD. The results shows the carbide of glucose is completely coated microspheres Co3O4particles, and highly dispersed on the graphene sheets. N2adsorption/desorption tests show that, thecomposite material has large specific surface area. When it applied as anodes in lithium-ion cells,C-Co3O4-FGS electrode exhibited the best electrochemical performance, which maintained844mA·h/g after50cycles at100mA/g current density. Its performance is superior to the single FGS、Co3O4and Co3O4-FGS. C-Co3O4-FGS composite materials can be used as a potential electrodematerial.Preparation and study on electrochemical performance of mesoporous carbon nanotubes-ferricoxide composite materials. MCNTs composites were prepared by solvothermal method.In this process,glycol was used as carbon source. Its specific capacity was maintained at889mA·h/g, capacityretention rate is90%after50charge-discharge cycles. MCNTs-Fe2O3composite material were prepared by dipping and low-temperature thermal decomposition method. The first dischargecapacity of composite material is1850mA·h/g at a current density of100mA/g. Compared with thefifth capacity, the capacity retention rate is close to100%after50charge and discharge cycles.

Related Dissertations

  1. Studies on Interfacial Electronic Structures of Transition Metal Oxide-based Intermediate Connectors in Tandem Organic Light-emitting Diodes,TN383.1
  2. Preparation of Honeycomb Fabric/Polyvinyl Chloride Composites and Sound Insulation Properties,TB332
  3. Flexible PVC insulation composites based methods and properties of,TQ325.3
  4. Preparation of Metal Oxides Electrode by Eelectrospining and Studies on Electrochemical Supercapactors,TM53
  5. Preparation of Silicon-based Alloy Anode Material Andelectrochemical Properties,TM912
  6. The Preparation, Microstructure and Propertities of the New Type 3D-Meshy SiC/Cu-Fe Composite Material,TB33
  7. Research of Graphitized Needle Coke Coated by Phenolic Resin Pyrolytic Carbon as Anode Material for Lithium Ion Battery,TM912
  8. Preparation and Modification of Lithium Ion Battery LiNi0.8Co0.05O2 Cathode,TM912
  9. The high fill SSP material PVC - based flexible sound insulation composite materials,TB34
  10. Study lithium titanate prepared from ilmenite,TM912
  11. Study on Fabrication Technology of Metal Oxide Coplanar Gas Sensor,TP212
  12. Supercritical Method Preparation for Lithium Iron Phosphate Nanometer Material and Its Carbon-coating Research,TM912
  13. Research on Functional Electrolytes for Lithium Ion Battery,TM912
  14. Study the Composites of Rare Earth β-Nucleating Agent/POM/EVA/Polypropylene,TQ320.1
  15. New lithium -ion battery anode material Li 4 Ti 5 O 12 Preparation and Modification,TM912
  16. Characterization studies selective oxidation of propane to acrylic acid compound catalyst,TQ225.131
  17. Study on Mechanical Properties of Multi-axial Carbon Warp-Knitted Reinforced Composite Materials with Glass-fiber Binder Yarn,TB332
  18. Preparation and Properties of ABS/Palygorskite Clay Composites,TB33
  19. Lithium battery cathode material of lithium vanadium phosphate synthesis and electrochemical properties of,TM912
  20. Mechanical Properties Analysis and Optimum Design of the Super-span Suspension Bridge with CFRP Cables,U448.25
  21. Design and Implementation on Battery Management System of EV,TM912

CLC: > Industrial Technology > Electrotechnical > Independent power supply technology (direct power) > Battery
© 2012 www.DissertationTopic.Net  Mobile