Printed Electrode Of Supercapacitor And Its Electrochemical Performance

Supercapacitor is a new style energy storage element between battery and traditionalstatic condenser. supercapacitor has advantage of high energy density, long cycle life andlarge specific capacitance compared with traditional capacitor, it can be used for electroniccomponents, small instruments and direct current converter to storage energy based onthese advantages. Recently, supercapacitor has already become a research hotpot due toits widely potential application. According to the different way of energy storage, it can bedivided into two types: electrochemical double-layer capacitor (EDLC) and Faradaypseudo-capacitance, the former electric material is carbon materials; the latter is metaloxides, conducting polymers and metallic compound. Electric materials and electrodefabrication are mainly research direction in this article.The work is done by iron oxide as electrode material of supercapacitor, containingfabrication and performance measurement of iron oxide. The all-solid-state flexiblesupercapacitor was fabricated with iron oxide and active carbon as an electrode material.The spherical, polyhedral and pit-like are prepared using hydrothermal method withferric chloride, sodium hydroxide and ethylene glycol (EG) as raw materials. These studyindicate concentration of ferric chloride have a big effect on morphology of α-Fe2O3. Thespherical ferroferric oxide(Fe3O4) is prepared with ferrous chloride, ferric chloride andsodium hydroxide as raw materials using coprecipitation method and Cetyltrimethylammonium bromide (CTAB) is surface active agent, its preparation process is simple, andaverage size is13.6nm, its dispersibility is good. The electrochemical performance ofα-Fe2O3and Fe3O4are measured by three-electrode method.Preparation the ink of supercapacitor electrode: the iron oxide (three kinds ofpurchasing from market and making by lab), MnO2(two kinds of purchasing from marketand making by lab) and active carbon (from the market) are electrode active materials,respectively. The Polyvinylidene Fluoride is bonder and acetylene black is conductiveagent, the ratio of three materials is8:1:1, a certain1-Methyl-2-pyrrolidinone (NMP) isused to solvent to prepare electrode ink of supercapacitor. The ink is coated on graphitepaper an area of1*1cm2as work electrode after drying for5h at120℃. The electrochemical performance of active carbon is performed by three-electrode setup in1MNa2SO4solution. The specific capacitance results show the MnO2is the highest, theactive carbon is higher, iron oxide is the lowest.Preparation and electrichemical performance measurement of all-solid-state flexiblesupercapacitor: the active carbon is active material, silver paste is collector andPVA-H2SO4gel is solid electrolyte to prepare supercapacitor electrode bydouble-electrode method to measure electrochemical. The result of specific capacitanceis0.34F/cm2when electrode material thick is15μm, and specific capacitance is0.36F/cm2when the electrode area is6.25cm2at5mV/s of scan rate through measurementelectrode material thickness and area. The specific capacitance retention is58%after1000cycles for6.25cm2of supercapacitor electrode area at5mA.