Raman Scattering Study On SWNT For Anode Material Of Lithium-ion Batteries And Correlative Problems

Carbon nanotubes are a kind of man-synthesized quasi-one-dimensional quantum wires. The finding of which not only enriches the people's perception of this common element in nature, but also facilitates the basic research of low dimensional materials. For its unique structural and the physical properties, carbon nanotubes (CNTs) have attracted much attention in the fields of nano-electronic devices, function materials, fuel cells, etc.Raman scattering is one of powerful means to research carbon nanotubes and plays an important role in understanding their structure and physical meaning. Especially, the in-stiu Raman signals can give us more instantaneous information in a dynamic process. For this, under the help of in-stiu Raman scattering instrument, the dissertation has focused on the deep understanding of the CNT and its action mechanism with the circumstances.The thesis contains six chapters. Chap. 1 is an introduction, which provides some historical background and basic subjects of CNTs such as structrue, properties, preparations, etc.In Chap. 2, firstly we show the principle and some basic methods of purification about the CNTs. Base on the character that our sample has many metal catalyzer particles, we design a method which mainly focus on the ultrasonic and acidification treatments, and complemently, with the gas-oxidation method. Then, we get the SWNT which has more concentrative diameter distributing. Finally, we discuss the possible impact on the structure of SWNT in the process of purification.The relationship between the Raman spectroscopy of SWNT and the surrounding conditions is discussed in Chap. 3. Under the comparation of some different structure of carbon, we find that the character lines have obvious Raman shift, which we ascribe to the graphine plan's curling and the curvature changes. While, for the influence of resonance, the character peaks of SWNT also have an obvious shift under the different excitated wavelengh. Using 457.5 nm excitation, we get the high quality 3rd order modes of SWNT. Finally, we study the difference of SWNT's spectrum on diverse substrates, and ascribe them to the heat exchange capability of the substrate materials. In fact, it is correlative to the change of environmental temperature, withal, we interpret in the power changing test.In Chap. 4, the Raman spectra of the SWNT film on Ag electrode are studied by the electrochemistry way. With the cycling of the voltage, the changes of the spectra show good reversibility, but the recovery has some relative hysteresis.Chap. 5 discusses the in-stiu Raman spectra of SWNT for anode material in Lithium-ion batteries. This process is a part reversible process, the irrecoverable changes in Raman spectra are corresponding to the damage of the reversible capacity in the first charge/discharge process. Moreover, the mutative velocity slowers with the further charge/discharge process.Surface-enhanced Raman scattering and adsorption studies of morphine on silver island film are done in Chap. 6, which helps a lot in the further understanding of DFT and SERS.