Date of Award
Master of Science (MS)
Super capacitors are considered the most prominent and efficient energy storage devices, next to lithium ion batteries due to their high power densities, fast charge-discharge capabilities and long cyclibility. Super capacitors possess high power density in comparison to batteries and these are able to solve the increasing demand for energy in small consumer products, electrical vehicles and devices where quick power delivery is highly desired. Super capacitors are classified into two categories based on their charge storage mechanism. The first group capacitors are called electrical double-layer capacitors (EDLCs), where the charge is stored at the interface. The second group is recognized as redox electrochemical capacitors (pseudo capacitors), where the charge storage arises due to Faradaic reactions at electrode/electrolyte interface. Although pseudo capacitors have higher charge storage capacity compared to EDLCs they suffer from high cost and poor cyclic stability. Since the charge-storage capacity of pseudo capacitors largely depends on the redox process at the electrode/electrolyte interface, their performance, which could be improved by using Nano-structured redox active materials.
Nanostructured materials have attracted considerable research interest for their applications as catalyst, energy storage, fuel cells, etc. The main objective of this work is to synthesize and characterize nanofibers of metal oxides using electro spun technique
and use them for energy storage applications. Various metal oxides such as NiMn2O4, CoMn2O4 and ZnMn2O4 were prepared as 1 dimensional (1-D) architecture using processable polymers and metal salts. The synthesized nanofibers were structurally and electrochemically characterized. The super capacitive performance of these nanofibers was examined using cyclic voltammetry (CV) and Galvano static charge-discharge techniques. The CoMn2O4 nanofibers showed a promising value of ~ 120 F/g in 3M NaOH. The effect of different electrolytes such as LiOH, NaOH and KOH on the electrochemical properties of these metal oxide nanofibers was also investigated. It was observed that the charge storage capacity depends on the electrolyte used. The supercapacitor device fabricated using these nanofibers showed that charge storage capacity increases with increase in temperature. Our results suggest that electro spun nanofibers could be used for energy storage applications.
Alkhalaf, Sara, "ELECTROSPUN NANOFIBERS OF METAL OXIDES FOR ENERGY STORAGE APPLICATIONS" (2016). Electronic Thesis Collection. Paper 95.