Modification of single walled carbon nanotube thin films for supercapacitor electrodes

Durukan, Mete Batuhan
Electrochemical capacitors, or supercapacitors, attracted a lot of attention in recent years due to their stability under numerous charge-discharge cycles, high charge discharge rates, and high power density when compared to batteries and conventional capacitors. Since their energy density is much lower than batteries, current research on supercapacitors is focused on improving the energy density through the development of novel active materials and innovative design of the electrodes. Carbon nanotubes are promising materials for batteries and supercapacitors with their unique morphology and electrical properties. They have highly accessible surface area, efficient electronic transport without scattering and high stability, all of which makes them suitable candidates as electrode materials for electrochemical capacitors. Furthermore, their composites in conjunction with pseudocapacitive materials are also investigated extensively primarily for the electrochemical performance enhancement. In this work, single walled carbon nanotube (SWNT) thin films are used as supercapacitor electrodes. Main idea of this thesis is to fabricate nanocomposite supercapacitors and micro-supercapacitors using cost effective and simple and scalable routes. In this regard, in the first part, SWNT thin film electrodes are used as current collectors and decorated with cobalt oxide (Co3O4) nanoflakes using electrodeposition and consecutive annealing process. A gravimetric capacitance of 313.9 F.g−1, corresponding to an areal specific capacitance of 70.5−2 is obtained from the fabricated electrodes at a scan rate of 1 mV/s. A capacity retention of up to 80% following 3000 charge/discharge cycles is obtained for the fabricated nanocomposite electrodes, while morphological evolution of the electrodes was monitored through high-resolution transmission electron microscopy during cycling. In the second part, are laser patterned SWNT thin films on glass substrates are used for the fabrication of micro-supercapacitors. Laser patterning is proposed for the formation of interdigitated electrodes. A specific capacitance of 3.50 at a scan rate of 10 mV/s was obtained from the SWNT buckypaper that was laser ablated to form interdigitated finger electrodes. A capacity retention up to 97% was attained at an applied current of 3 mA following 1000 charge/discharge cycles.


Development of Nanocomposite Electrodes and Separators for Supercapacitors
Aydınlı, Alptekin; Ünalan, Hüsnü Emrah; Department of Metallurgical and Materials Engineering (2022-2-10)
Supercapacitors or electrochemical capacitors are known as one of the most promising energy storage systems for the 21st century. Having the potential to complement batteries, supercapacitors have received a lot of attention thanks to their high specific power and moderate energy densities. Supercapacitors have various application areas ranging from electric vehicles to portable systems and devices. In particular, their fast charge-discharge feature enables integration with consumer electronics, mobile devi...
Enhanced supercapacitors from hierarchical carbon nanotube and nanohorn architectures
Hiralal, Pritesh; Wang, Haolan; Ünalan, Hüsnü Emrah; Liu, Yinglin; Rouvala, Markku; Wei, Di; Andrew, Piers; Amaratunga, Gehan A. J. (2011-01-01)
Supercapacitors fill the power and energy gap between electrolytic capacitors and batteries. The energy density for commercial supercapacitors is currently limited to similar to 5 Wh kg similar to 1. Enhancing the energy and power density of supercapacitors is of great interest as it would open up a much wider range of applications. In this work, thin film supercapacitors made of random networks of single-walled carbon nanotubes (SWNTs) were enhanced by the use of carbon nanoparticles of a size ideal to fil...
Hierarchical multi-component nanofiber separators for lithium polysulfide capture in lithium-sulfur batteries: an experimental and molecular modeling study
Zhu, Jiadeng; Yıldırım, Erol; Aly, Karim; Shen, Jialong; Chen, Chen; Lu, Yao; Jiang, Mengjin; Kim, David; Tonelli, Alan E.; Pasquinelli, Melissa A.; Bradford, Philip D.; Zhang, Xiangwu (2016-01-01)
Sulfur (S) has been considered as a promising cathode candidate for lithium batteries due to its high theoretical specific capacity and energy density. However, the low active material utilization, severe capacity fading, and short lifespan of the resultant lithium-sulfur (Li-S) batteries have greatly hindered their practicality. In this work, a multi-functional polyacrylonitrile/silica nanofiber membrane with an integral ultralight and thin multi-walled carbon nanotube sheet is presented and it provides a ...
Mathematical modeling of adsorption/desorption systems for chemical heat pumps
Yurtsever, Ahmet Onur; Uludağ, Yusuf; Karakaş, Gürkan; Department of Chemical Engineering (2011)
Despite their limited commercial applications, chemical heat pumps (CHP) have been considered as an important alternative to conventional heating and cooling technologies. In this study, the adsorption-desorption of ethanol over activated carbon was applied on the CHP reactor. The ethanol vapor - activated carbon adsorption rate was determined at 30, 60, 90 and 120° experimentally by using Intelligent Gravimetric Analyzer C(IGA). The experimental adsorption data were used on the transient modeling of reacto...
Modification of TiO2 and NiO charge selective mesoporous layers using excessive Y and Li additions for carbon based perovskite solar cells
Icli, Kerem Cagatay; Özenbaş, Ahmet Macit (2021-09-15)
Carbon based perovskite solar cells are rapidly emerging as promising photovoltaic devices, combining low cost production and prolonged device operation, due to the exclusion of polymeric conductors and integration of highly durable metal oxide charge selective layers. Modification of metal oxide mesoporous layers via element additions and enhancement of electrical conductivity is a major strategy for reduced internal resistances inside the cell. This work investigates the effect of excessive Y and Li addit...
Citation Formats
M. B. Durukan, “Modification of single walled carbon nanotube thin films for supercapacitor electrodes,” M.S. - Master of Science, Middle East Technical University, 2017.