Tinate nanotubes combine with Graphene based materials as a novel anode material for Lithium ion batteries
Material Science and Engineering department, Master Thesis, 2016
Assoc. Prof. Dr. Selmiye Alkan Gürsel (Thesis advisor)
Dr. Alp Yürüm (Thesis co-advisor)
Prof. Dr. Ayşe Gül Gürek
Assoc. Prof. Dr. Gözde Ince
Date &Time: 10-08-2016&14:00 pm
Place: FENS G035
Keywords : Lithium-ion batteries, rechargeable batteries, anode, titanate nanotubes, functionalized graphene
The shortage and inhomogeneous distribution of conventional energy gives rise to the intensive research on electrochemical energy storage and conversion. Seeing many types of rechargeable battery have been under research by far, lithium-ion batteries (LIBs) shine out with its promising volume capacity and significantly higher weight capacity. Being compatible with the main considers of anode candidates, TiO2 has been chosen with its capacity theoretically ups to 335 mAh/g provided that a complete reduction from Ti4+ to Ti3+ could be exploited. Meanwhile, its environmentally benign nature makes it a hot research topic worldwide. TiO2 features as nontoxic, as well as cost effective. Nevertheless, Poor electronic conductivity and low rate capability are the main drawbacks which can be overcome by synergetic effect by material composite. Graphene based material comes with such expectation as it has excellent electronic conductivity, high surface area, mechanical strength and chemical resistance which indicate graphene can be an ideal material for being a promising conductive network and stain buffer.
In our research, several types of composite titanate(H2Ti3O7) with graphene based materials are prepared and characterized for lithium ion battery. Titanate nanotubes (TiNTs) were in-situ grew and embeded on the surface provided by GO, aminated graphene oxide nanocomposites (GO-NH2), nitrogen doped graphene nanoplates (NGNP), via one-step hydrothermal method, respectively. The structural and morphological analysis of the samples were performed by X-ray powder diffraction (XRD), Brunauer-Emmentt-Teller (BET) analysis, x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and RAMAN spectroscopy. Cyclic voltmeter (CV) was operated to explore the oxidation-reduction relation with current-voltage parameters. Charge-discharge tests were employed to evaluate energy storage capacity corresponding to applied voltage and current to characterize their performance and durability. Results indicated that the composites we produced can be promising anode materials for Lithium ion battery.