Improving the performance of li-iyon battery by coating anode with titanium dioxide (TİO2) added poly (ethylene oxide) nanocomposite

The rechargeable lithium-ion batteries are classified as secondary batteries. In order to increase the performance of lithium-ion batteries, investigations have been carried out to improve the properties of components such as anode electrode, separator, electrolyte and cathode electrode. The increase in the performance of lithium-ion batteries can be achieved by improving the characteristics of the battery such as energy density, specific capacity and operating voltage. The improvement of these properties can be provided especially by increasing the efficiency of the electrodes that compose the battery. The superior properties of lithium-ion batteries compared to other rechargeable batteries are primarily due to the superior properties of element lithium. Li metal; It is preferred as the anode material due to its high theoretical capacity (3860 mAh/g), low density (0.59 g/cm3) and low redox potential (-3.04 V versus standard hydrogen electrode). However, since lithium metal can react with organic solvents, a surface film is formed during the initial charge/discharge processes. The electrically insulator and ionically conductive interface is termed the solid electrolyte interface. The formation of solid electrolyte interphase consumes the anode and electrolyte, leading to low efficiency. In addition, lithium dissolution at the Li/electrolyte interface causes pits and voids, resulting in inactive lithium formation and deterioration of the lithium electrode. In this study, lithium metal anode was coated with titanium dioxide (TiO2) doped poly (ethylene oxide) (PEO) nanocomposite in order to prevent the contact of lithium metal with electrolyte and suppress dendritic growth. In order to observe the effect of coating layer, batteries were produced by using uncoated, PEO coated and PEO nanocomposite coated with 0.5%, 1%, 2.5% by weight TiO2 doped lithium metals as anodes. The cycle performance, cyclic voltammetry, electrochemical impedance spectroscopy analyzes were performed on the produced batteries. X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and differential scanning calorimetry tests were performed for the coating layers. As a result of the tests, the batteries using anodes coated with 1% TiO2 doped PEO nanocomposite had the highest specific capacity with 157.98 mAh/g at slow charge/discharge current densities. The effect of coating the anode surface with nano-sized TiO2 additive was observed for 100 cycles and the increase in performance was proven with tests.