Production of nanocrystalline tin and tin based alloys and na-ion battery applications

Li-ion batteries have significantly dominated the rechargeable battery market due to their superior energy density for the past 25 years. Recent trends on Li-ion batteries is now moving towards to the electrical vehicles. Nevertheless, due to the limited lithium reserves and increasing lithium based chemicals will soon block the battery market. Therefore, there is an increasing interest on potential alternatives for energy storage such as Na-ion batteries. It is well known that both lithium and sodium are alkali metals and have similar chemical properties. However, large ionic radius with slower ionic diffusion rates faces many challenges on Na-ion battery researches. In this thesis study, tin based novel electrode materials as an anode electrode for this type of batteries are investigated in detail. A facile chemical reduction method is developed for nanocrystalline tin and nickel-tin intermetallic structures. Although tin and tin based intermetallic nano structures as an anode active materials have a high theoretical capacity, the large volume change during sodiation/desodiation and low intrinsic conductivity hamper its electrochemical performance. Since graphene has large surface area, high electrical conductivity and discharge capacity, tin/graphene, nickel-tin/graphene nanocomposite anodes in proper architectures alleviate difficulties to improve electrochemical performances of the sodium ion batteries. Here we report a well-designed sodium ion battery anode in which carbon-coated tin and nickel-tin nanoparticles which are stable mechanical support and rapid electron conduction. Furthermore, we improved the integral stability of the electrode through introducing amorphous carbon. The as-synthesized active materials obtained were examined by X-Ray Diffraction analysis and field emission electron microscopy analysis in order to evaluate the morphological structures. The anode electrodes were also studied by Galvanostatic Cycling and Electrochemical Impedance Spectroscopy (EIS)