Master of Science in Engineering (MSEgr), Wright State University, 2011, Materials Science and Engineering

Improvements of the anode performances in Li-ions batteries are in demand to satisfy applications in transportation. In comparison with graphitic carbons, transition metal oxides as well as graphene can store over twice amount of lithium per gram. Recently, graphene-based anodes for Li-ion batteries are under extensive development. In this research, lithium storage characteristics in graphene oxide (GO), GO/Manganese acetate (GO/MnAc), GO/manganese oxide (GO/MnOx) composites and Nano Graphene Platelets (NGP) were studied. The prepared GO delivered reversible capacities of 706mAh/g with an average columbic efficiency of 87%. Reversible capacities of 533 mAh/g were observed for GO/MnAc composite. GO/MnOx nanocomposite thermal annealed at 400°C in inert atmosphere exhibited high reversible charge capacity of 798 mAh/g with an average columbic efficiency of 95% and capacity fade per cycle of 1.8%. The EIS spectra of discharge and charge profiles of GO and GO/MnOx composites were analyzed to investigate the kinetics evolution of electrode process at different stages of lithium storage.

Committee: Hong Huang PhD (Advisor); Daniel Young PhD (Committee Member); Chu Kuan-lun PhD (Committee Member); George Huang PhD (Other) Subjects: Alternative Energy; Automotive Materials; Chemistry; Energy; Engineering; Materials Science; Metallurgy; Nanotechnology

Doctor of Philosophy, The Ohio State University, 2022, Chemistry

Covalent organic frameworks (COFs) are an emerging class of crystalline porous organic polymers composed of light elements (C, H, N, O, and B) connected through strong covalent bonds. The design and syntheses of COFs primarily relies on the principles of dynamic covalent chemistry in conjunction with non-covalent interactions. COF structures are often accessed via the utilization of reversible bond-forming reactions under reaction conditions that promote this reversibility to achieve porous, ordered materials that can be characterized as having high surface areas, permanent porosities, low densities, and high chemical and thermal stabilities. One of the prominent advantages of COFs is their modular nature. Through reticular chemistry, careful structure design, and choice of building units can allow for the fabrication of materials suited for specific applications. These principles have been employed to tune the stability, crystallinity, and properties of different materials.COFs also possess a high degree of π-conjugation and are insoluble in most common organic solvents. These attractive assets have made COFs of great interest in a range of applications and fields including chemical sensing, energy storage, catalysis, and gas capture and storage. This research will focus on the design of COFs for use as organic anode materials in potassium ion batteries as well as the investigation of their thermal conductivities. There is currently growing interest in the development of organic electrode materials for energy storage devices due to their sustainability and low costs. Currently, the industry standard anode material is graphite, a material that has yet to reach its theoretical potential. In efforts to synthesize a layered material with properties similar to the carbon allotrope, graphyne, two alkynyl-containing COFs were investigated as potential organic anode materials in potassium ion batteries; TAEB-COF and DBA-COF 3. After 300 cycles at a current density of (open full item for complete abstract)

Committee: Psaras McGrier (Advisor); Jovica Badjic (Committee Member); Jon Parquette (Committee Member) Subjects: Chemistry