MOF-derived nanostructured porous carbon for supercapacitor electrodes

• Main Author: Tengku Norafiqah Binte Tuan Abdul Aziz
• Other Authors: Yan Qingyu
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/66414
• Institution: Nanyang Technological University

In the current years, metal-organic frameworks (MOF) have been an attractive development/advancement of electrode materials for the supercapacitor application due to its intriguing properties and the ability to serve as both carbon precursor and template in the formation of nano-porous carbon (NPC). Through carbonizing of ZIF-67, where ZIF-67 is formed from the reaction between cobalt nitrate and 2-methylimidazole along with methanol and ethanol, NPC were synthesized. The properties of these materials were characterized for their morphology, the elemental composition, phase purity, thermal stability, BET surface area. Besides that, it was explored how the formation of MnO2 needles on the surface of NPC by doping MnO2 into NPC influenced the properties. In this study, the synthesized NPC and MnO2-doped NPC composites’ capacitive/electrochemical properties were examined by employing cyclic voltammetry (CV). NPC showed specific capacitances ranging from 15 – 34 F/g meanwhile MnO2-doped NPC exhibited specific capacitances varying from 60 – 123 F/g at scan rates of 5 – 200 mV/s. Additionally, from the charge/discharge graph set at current density of 10 A/g, the capacitance retention and the ratio of the capacitance retention for both NPC and MnO2-doped NPC were obtained. NPC showed excellent long term cycle stability throughout the remaining cycles even though there is 5 % drop within 250 cycles. On the other hand, beyond 600 cycles, there is gradual 5 % decrease observed in the specific capacitance of MnO2-doped NPC before establishing the stability of NPC at 1400 cycles.