Skip to content Skip to navigation
University of Warwick
  • Study
  • |
  • Research
  • |
  • Business
  • |
  • Alumni
  • |
  • News
  • |
  • About

University of Warwick
Publications service & WRAP

Highlight your research

  • WRAP
    • Home
    • Search WRAP
    • Browse by Warwick Author
    • Browse WRAP by Year
    • Browse WRAP by Subject
    • Browse WRAP by Department
    • Browse WRAP by Funder
    • Browse Theses by Department
  • Publications Service
    • Home
    • Search Publications Service
    • Browse by Warwick Author
    • Browse Publications service by Year
    • Browse Publications service by Subject
    • Browse Publications service by Department
    • Browse Publications service by Funder
  • Help & Advice
University of Warwick

The Library

  • Login
  • Admin

Development of advanced electrode materials for high-performance supercapacitors

Tools
- Tools
+ Tools

Du, Dongwei (2018) Development of advanced electrode materials for high-performance supercapacitors. PhD thesis, University of Warwick.

[img]
Preview
PDF
WRAP_Theses_Du_2018.pdf - Submitted Version - Requires a PDF viewer.

Download (13Mb) | Preview
Official URL: http://webcat.warwick.ac.uk/record=b3226868~S15

Request Changes to record.

Abstract

The demand for high-performance electrochemical energy storage devices is ever-growing as they are critical components for portable electronics, electric vehicles, and efficient storage media for energy from renewable sources. Electrochemical capacitors (also called supercapacitors) are emerging as one of the most promising candidates due to their rapid charge rate, high power density, good rate capability and excellent lifespan. However, their usage is significantly limited by the disadvantages of low energy density. The main aim of this work is to develop advanced electrode materials for supercapacitors with improved energy density while maintaining high power density and long cycle life.

In this thesis, we have developed four novel electrode materials based on the transition metals of Ni and Cu for supercapacitor applications, including the metal oxides (Li2Ni2(MoO4)3 and Cu2O/CuMoO4) and metal sulfides (NiMoS4-A and Ni-Cu-S). These materials were prepared via different techniques, such as combustion, chemical co-precipitation and hydrothermal. Their physical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) etc. Their electrochemical behaviours were evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and cycling stability etc. To further measure the performance in practical energy storage devices, the materials were tested with a two-electrode configuration. All the four materials were used as positive electrodes, which were paired with proper activated carbon (AC) or nitrogen-doped graphene (NG) negative electrodes to assemble asymmetric supercapacitors (ASCs).

At a current density of 1 A g-1, the Cu2O/CuMoO4 electrode exhibits a high specific capacitance of 4264 F g-1, superior to the1137 F g-1 of the Li2Ni2(MoO4)3, 706.5 F g-1 of the NiMoS4-A, and 938.6 F g-1 of the Ni-Cu-S. In terms of the ASCs, the Cu2O/CuMoO4//AC ASC could expand the operation voltage to 1.7 V, at which the energy density can reach 75.1 Wh kg-1 with a power density of 420 W kg-1. The NiMoS4-A//AC ASC displays a high energy density of 35 Wh kg-1 at an average power density of 400 W kg-1. Meanwhile, it exhibits excellent cycle stability, maintaining 82% of the initial capacitance after 10000 charge-discharge cycles at 5 A g-1. These good results suggest that the developed materials are promising for high-performance supercapacitor applications.

Item Type: Thesis or Dissertation (PhD)
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
Library of Congress Subject Headings (LCSH): Supercapacitors, Electrodes -- Materials, Energy storage, Electric capacity
Official Date: January 2018
Dates:
DateEvent
January 2018Submitted
Institution: University of Warwick
Theses Department: School of Engineering
Thesis Type: PhD
Publication Status: Unpublished
Supervisor(s)/Advisor: Tao, Shanwen
Format of File: pdf
Extent: xxv, 213 leaves : illustrations, charts
Language: eng

Request changes or add full text files to a record

Repository staff actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics

twitter

Email us: wrap@warwick.ac.uk
Contact Details
About Us