| Author: | Lu, Xiao |
| Title: | Graphene-metal nanocomposite in energy applications |
| Advisors: | Zheng, G. P. (ME) |
| Degree: | M.Sc. |
| Year: | 2017 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Energy storage Nanostructured materials Electric batteries -- Materials Supercapacitors -- Materials |
| Department: | Faculty of Engineering |
| Pages: | ix, 60 pages : color illustrations |
| Language: | English |
| Abstract: | Graphene Aerogel(GA), or aero-graphene, is a low-density and high porous 3D solid consisted of graphene. It has simply composition, good conductivity, and light weight. Its highly-porous structure can produce large surface area to attract ions in electrolytes. So it is a future candidate of the electrode material of Lithium-ion battery and supercapacitor. To improve its performance, a GA-metal nanocomposite is produced in this thesis by electrodeposition method. Cobalt-Iron-Phosphorus metallic glass film was successfully deposited on Titanium plate at first stage. Then the Co-Fe-P nanoparticles were successfully embedded into GA under the same depositing condition of Ti plate, which is 50℃-60℃, pH=5, and under constant voltage at 1.000V. The depositing time is controlled to get different sizes of the nanoparticles. Several other different values of temperature and pH values are applied to explore the ideal condition of the deposition progress. About 25 samples are made on this step. X-ray Diffractor, Scanning Electron Microscope and Energy Dispersive X-Ray Spectroscopy are used to check the phase, nanostructure and element component of the GA-metal composite samples. The analysis shows that the Co-Fe-P nanoparticles are well deposited and uniformly distributed in GA. The particle size increases clearly as the deposition time extended. The results also show that it is more likely to get amorphous deposits in GA under the similar condition of that on Titanium than other different conditions. Electrochemical measurement is applied to test the performance of one selected GA sample which is deposited at the condition of 60℃, pH=5, 18h. The results show that the maximum capacity is about 220 mA·h/g and the coulombic efficiency keeps stable around 96%. The capacity decreases slowly with the charge-discharge circle increases. The proper capacity and low Faradaic loss indicate that the GA-metal composite is a good material for electrode in Lithium-ion battery. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 991021962223503411.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 7.16 MB | Adobe PDF | View/Open |
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