| Author: | Shi, Fangyi |
| Title: | A transparent cathode for lithium sulfur batteries |
| Advisors: | Zhou, Limin (M |
| Degree: | M.Sc. |
| Year: | 2018 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Lithium sulfur batteries |
| Department: | Faculty of Engineering |
| Pages: | vi, 118 pages : color illustrations |
| Language: | English |
| Abstract: | Transparent batteries have attracted many attentions as they can play an important role in transparent devices like displays, phones, watches and energy windows. Though some researchers focus on the researches of transparent lithium ion batteries (LIBs), there are few researches on the transparent lithium sulfur batteries (LSBs). Moreover, the LSBs show almost four times energy density than that of LIBs (based ongraphiteanodes and LiNi₁/₃Mn₁/₃Co₁/₃O₂ cathodes). In this research, a new transparent cathode of LSBs was designed and prepared successfully. The light and semi-transparent graphene woven fabrics can be used to prepare binder-free cathode for their one-piece structure. The average transparency of the cathode with grid structure can arrive about 33% in the visible light. The lines' diameter of 45µm in the mesh structure is lower than the human eyes' resolution, which causes the opaque parts hardly being distinguished with the transparent parts. Sulfur was successfully loaded in the GWFs through solution and melting methods. XRD, Raman, SEM, and TEM testing methods were also used to confirm the cathode's compositions, structures, and morphology. The results show that sulfur homogeneously distributes on materials, which cannot be observed by human eyes. There is no obvious change in the transparency of the cathodes after the sulfur loading. The prepared GWFs-S cathodes show the capacity of 375 mA h g⁻¹ and 250 mA h g⁻¹ can still be remained after 100 cycles. Furthermore, a stable relative capacity of 220 mA h g⁻¹ could be recovered when the discharge current was decreased from 1C to 0.1C. In order to impair the shuttle effect resulting from lithium polysulfide, PVP, an amphiphilic chemical which can help absorb the lithium polysulfide, was successfully introduced to the GWFs-S. The capacity increased to 610 mA h g⁻¹ by adding PVP and gradually dropped to 390 mA h g⁻¹ after 100 cycles. This transparent cathode shows a good electrochemical performance in open graphene structure. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 991022159055003411.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.6 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/9583