Electrophoretic deposition of molybdenum disulfide (MoS2) nanosheets on conductive substrates for supercapacitor

• Main Author: Tay, Shemilyn Li Ping.
• Other Authors: Zhang Hua
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/51497
• Institution: Nanyang Technological University

Molybdenum disulfide (MoS2) nanosheets have a structure analogous to graphene and their properties such as high surface area and electric conductivity make MoS2 attractive to be studied in energy storage applications such as supercapacitor. In this project, electrophoretic deposition (EPD) was employed as a facile method to deposit MoS2 nanosheets on conductive substrates to prepare MoS2 electrodes for supercapacitor. It was found that EPD was able to successfully deposit MoS2 nanosheets on a variety of substrates. The supercapacitor performances of MoS2/Ni foam and MoS2/Ni foil electrodes were studied particularly. Characterization studies of MoS2/Ni foam by SEM and SEM-EDS showed that MoS2 nanosheets formed a well-distributed porous morphology on the 3D network of nickel foam. Compared to pure nickel foam, MoS2/Ni foam provided enhanced supercapacitor performances. Electrochemical measurements revealed that the electrodes of MoS2/Ni foam and MoS2/Ni foil operate mainly via the electrochemical double layer and their maximum specific capacitances are 124.49F/g and 41.25F/g respectively at scan rate of 5mV/s. The higher specific capacitance of MoS2/Ni foam was attributed to its 3D network, which provided increased area for charge storage. Several modifications that were made to the system such as addition of Mg(NO3)2 in EPD suspension to enhance deposition efficiency and usage of LiOH as an alternative electrolyte did not produce favourable results. Lastly, the electrochemical impedance spectroscopy test revealed that MoS2/Ni foam electrode had a lower equivalent series resistance than MoS2/Ni foil electrode.