SYNTHESIS OF OLIVINE TYPE CATHODE ACTIVE MATERIAL (LiFePO4/C)FOR LITHIUM ION BATTERIES BY HYDROTHERMAL METHOD
Project no. 716 · Status: Kapanmış · 2016
Summary
According to the reduction of the reserves of the fossil fuels, and formation of the greenhouse gases due to the usage of these fuels; causes environmental problems and limits the usage of this kind of fuels. Especially, the use of these sources as a fuel in vehicles, leads to produce alternative solutions. Renewable energy sources (wind, sun, etc.) can be considered as one of the solutions. Storage of this kind of energy in continuity and the use of the energy storage system, when energy supply is interrupted, is a requirement. Rechargeable batteries are widely used for the storage of energy. Among these rechargeable batteries, lithium-ion batteries with high energy density, are used in cars, industrial vehicles, boats, submarines, in a wide range of electronic devices from mobile phones to laptops. High performance lithium ion batteries are very important for the production of new generation electrical vehicles; in particular, our country is more dependent on external lithium-ion battery demand. The main cost effective component of the production of the lithium ion batteries is the cathode material. For this kind of batteries, cathode material is generally produced by solid state synthesis. More rapid and economical production possibilities have been investigated since this method is expensive and has several processing steps. Cathode material that obtained by hydrothermal synthesis has smaller particle size (micro or nano), higher performance and higher theoretical capacity compared to other methods. Scope of this project is the production of nano-sized LiFePO4/C as a cathode material for rechargeable Li-ion batteries, at different reaction conditions (temperature, pressure and time) by hydrothermal synthesis method. In the literature, no evidence of any studies examining the effect reaction pressure on synthesized cathode material. Iron sulfate 7-hydrate (FeSO4.7H2O), ortho-phosphoric acid (o- H3PO4), lithium hydroxide (LiOH) and pure water are mixed in different portions and will be heated sub and super-critical conditions, in a 100 cm3 reactor. For the first time, sodium sulfite (Na2SO3) and sodium dodecyl sulphate will be used as antioxidant agent and carbon source, respectively. Oxidation of Fe+2 to the Fe+3 and/or Fe+4 will be obstructed by antioxidant agent. Cathode active material which is produced after reaction will be analyzed with methods such as SEM-EDX, XRD, FT-IR. With this characterization study, particle size, size distributions, surface morphology, element content, purity, unit cell parameter, crystal size and functional groups of the structure will be identified. This project will be a basis and guide for the further researches for energy storage subject, which is very important for our country. By the way, this project will provide to publish journals at international publications, which will contribute to increase the scientific level of the country at SCI. Also, it will provide to produce cathode active material in a more economical way in our country with our own equity. For this purpose, this project will be a model for new battery production facilities which would like to invest this kind of production. Development of next generation battery technologies will contribute to widespread use of electric vehicles. By increasing the capacity of Li-ion batteries, a step will have been taken in the development of battery technology.