Electrochemical Capacitance Of Nanosized Metal Oxide Composite Electrodes

Recently, research on the electrochemical capacitors (ECs) has received a great deal of attention for use in high-power energy storage devices because of higher power density than battery and higher energy density than conventional capacitors. The capacitance in an electrochemical capacitor can arise from the charging or discharging of the electrical double layers or from Faradaic redox reactions (pseudocapacitance). The latter gives a larger capacitance value compared to the former and was called supercapacitors. Many approaches have been pursued in the development and characterization of new electrode materials for the better capacitive performance. This dissertation consists of four parts. The next section is the content of each part.The first chapter is to present the fundamental principles, characterizations and applications of supercapacitors, especially the recent progress of researches on supercapacitors using carbon, transition metal oxide and its composites as electrode materials. Based on this information I put forward my purposes and researches to solve some existed questions.The second chapter shows the preparation of amorphous Ru1-yCryO2/TiO2 nanocomposite and its electrochemical capacitance performance. It was synthesized by loading various amount of Ru1-yCryO2 via a reduction of aqueous K2Cr2O7 with ruthenium (â…¢) chloride on TiO2 nanotubes. XRD, TEM, SEM, cycle voltammetry and galvanostatic charging/discharging tests were applied to investigate the morphology, crystalline and electrochemical properties of the composite electrodes. A good electrochemical capacitance performance were proved by the tests due to that the three dimensional nanotube network of TiO2 and thus will be one of approach for economizing the noble metal ruthenium.The third chapter shows the synthesis and electrochemical capacitance performance of...