Fabrication And Electrochemistry Performance Of In-situ Growth Of Thin Film Electrode Materials On Metallic Substrates

With the rapid development of the modern society, energy materialshave become more and more important, scientists have paid greatattention to the materials which possessed the fast charge/dischargeefficiency, high energy storage and stable performance. In recent years,the most widely research is electrochemical energy storage materials,their development precess is from the initial nickel-cadmiu battery tolithium-ion battery of optimizational energy storage property until theelectrochemical capacitors of fast charging time and long circular life, asknown as the supercapacitor now. This kind of capacitor consists of threecategories: carbon materials, conductive polymer materials and metaloxide/sulfide materials. According to the different physical and chemicalproperties of materials, the corresponding modified electrodes possess thedifferent energy density, cycle life and other properties. At present, thesupercapacitor has applied in the field of electric vehicle, intelligentdevice, electric power system and solar products and so forth in our dailylife. Based on the inequality energy storage mechanism, thesupercapacitor can be divided into two types, the former capacitor whichcomposed of active carbon material, carbon fiber, carbon nanotubes andother carbon materials is called double electric layer capacitor, and thelatter capacitor which composed of metal oxide and polymer materials iscalled Faraday pseudo capacitor. We have studied the two types of capacitors in our paper, the fourprepared electrodes such as: titanium foam based PPy electrode material,nickel foam based PPy/Ag composite electrode material, nickel foambased carbon thin film electrode material and copper foil based CuSelectrode material. The common characteristic of these four preparedelectrodes is nano/micro thin film materials which directly grow on themetal substrates without any adhesion agents, there are no otherimpurities getting into the experimental process. The morphologycharacterization and component analysis of the prepared electrodes areusing the instruments such as: scanning electron microscope (SEM),transmission electron microscope (TEM), ultraviolet visible spectrometer(UV) and infrared visible spectrophotometer (FTIR), and theelectrochemical property of electrodes is measured by cyclic voltammetry(CV), constant currrent charge discharge (GCD) and cycle life test onElectrochemical Workstation. In this paper, we have compared themorphology and electrochemical properties of prepared electrodes withthe different reaction times and different reactant concentrations, then wecan obtain the most appropriate electrode material. For instance, thetitanium foam based PPy modified electrode with the reaction time of12hours possesses the specific capacitance of855F g-1in1A g-1currentdensity; The nickel foam based PPy/Ag modified electrode with thereaction time of7hours possesses the specific capacitance of493F g-1in1A g-1current density; The carbon modified nickel foam electrode whichprepared in glucose hydrothermal method possesses the bettercapacitance property and longer cycle life than the same type of carbonmaterials; And the copper foil based CuS thin film electrode whichsynthetised in0.1mol L-1CuSO4and Na2S2O3solutions with18hreactiop time possesses the high specific capacitance of1093F g-1(1A g-1). As the major preparation method, the in-situ growth method is thecharacteristic of this paper. The excellent electrode which prepared insimple operating environment and convenient preparation process couldbe the new development direction in the electrochemical supercapacitorfield.