Dissertation > Excellent graduate degree dissertation topics show

Modification and Electrochemical Properties of Low-Temperature Exfoliated Graphene

Author: YouCongHui
Tutor: YangQuanHong
School: Tianjin University
Course: Applied Chemistry
Keywords: graphene transmittance tunable graphene oxide membrane supercapacitor lithium-ion battery(LIB) conductive additive negative electrode
CLC: TM912
Type: Master's thesis
Year: 2010
Downloads: 312
Quote: 0
Read: Download Dissertation

Abstract


Graphene, which is characterized by high surface area and good conductivity, is a kind of flexible two-dimensional carbon material that has potential applications in the area of solar cells, supercapacitors and lithium-ion battery (LIB). In this study, transmittance tunable graphene oxide membrane is prepared by a liquid-air interface self-assembly method and electrochemical properties of low-temperature exfoliated graphene are investigated with the focus on potential applications as supercapacitor electrode materials, conductive additives for LIB and negative electrode materials for LIB.Graphene oxide (GO) membrane whose transmittance can be tuned precisely is prepared by a liquid-air interface self-assembly method. The transmittance of the GO suspension and the resulting membrane both decrease with the increase of the pH value (pH: 2~13) of the parent suspension. The comparison results show higher and lower transmittances can be obtained for the resulting membranes when the pH values are 2.0 and 11.0 respectively.The electrochemical properties of supercapacitors based on graphene that is treated under different temperature are amazingly different. With the increase of the heat-treatment temperature, the capacitance of graphene-based supercapacitors with aqueous electrolytes shows a declined trend with an exceptional case where the heat-treatment temperature is 300℃. The capacitances of original graphene(GN) and graphene that treated at 900℃(GN(900)) are 250 and 25 F/g respectively with the current density of 50 mA/g. Graphene treated at 300℃(GN(300)) shows the largest capacitance which is up to 302 F/g at the same current density. With the organic electrolytes, the graphene based capacitances show a monotonously increasing trend with the increase of the heat-treatment temperature.Graphene shows excellent performance as the conductive additive of LIB. The battery shows higher performance when the content of graphene is low (2 wt%) and the graphenes after heat-treatment show higher performance. As compared to the battery with Super-P (20 wt%) as additives, the graphene-introduced battery (2 wt%) that treated at 500℃shows much better performance.Graphene as the negative electrode material of LIB reveals high capacity that is up to 905 mAh/g in the first cycle but no charge/discharge platform appears. When graphene/Al composite is employed as the negative electrode material, the battery shows very high capacity (up to 1134 at first cycle), low/smooth platform (0.42V) and good cycling performance.

Related Dissertations

  1. Synthesis and Study on Graphene and Co3O4/Graphene Composite about the Characteristics of Electrochemistry,O613.71
  2. Preparation of graphene Defects,O613.71
  3. WC / graphene composite electronic structure and electron transport properties,O613.71
  4. Preparation of Functional Multi-walled Carbon Nanotubes for Using in Electrochemical Capacitor Materials and Its Electrochemical Performance,TB383.1
  5. Preparation of Surface-functionalized Graphene and Its Influence on the Mechanical Properties of Nanocomposite Materials,TB332
  6. Study on the Graphene Preparation on Cu–Ni Alloy Substrate by Chemical Vapor Deposition,O484.1
  7. Studies on Modeling and Control of Distributed Energy Storage System in Microgrid,TM919
  8. A New Type of Structure of the Graphene Nano Device,TB383.1
  9. Preparation and Characterization of Graphene/Titanate Nanotubes Photocatalysts,TB383.1
  10. Based on the two-dimensional graphene composites and preliminary application of,TB332
  11. Graphene electrode preparation and Its Electrocatalytic Performance PBDEs debromination,O613.71
  12. Graphene and other substrates SnO Arrays growth , performance and Devices,TB383.1
  13. Fe 3 O 4 , carbon nanotubes and graphene reinforced regenerated cellulose membrane research,TB383.1
  14. Super capacitor energy storage system DC conversion technology research,TM53
  15. Super capacitor voltage balance System,TM53
  16. Layered Ppy / CRGO Nanocomposites Preparation and Application in Supercapacitors,TM53
  17. Composite Supercapacitor Electrode Materials Preparation and Properties,TM53
  18. Nanoporous materials absorb harmful gases grand canonical Monte Carlo,TB383.1
  19. Poly ( urethane - vinyl imidazole ) copolymer / graphene nano- composites,TB383.1
  20. Strain-based graphene nanodevices design,TB383.1
  21. Based graphene material , a Novel DNA biosensor,TP212.2

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