Graphene/Titanium Dioxide Composite Material Performance Study Of Supercapacitor

Supercapacitor having a high capacity, high power density, long life, low temperature limit and good electrochemical properties, is an efficient, stable energy and environmentally friendly storage device. Electrochemical supercapacitor performance depends on the performance of its electrode material. Carbon-based material conductivity, lower prices, preparation process is relatively simple, high electrochemical stability, but its low capacity, precious metal oxides such as oxidation of the high price of ruthenium, preparation of complex, but its high specific capacitance. Therefore, alternative metal also appears as titanium oxide, manganese oxide, cobalt, etc. Graphene is a carbon-based material is undoubtedly the best carbon materials, its high specific surface area, high conductivity is the super capacitor required. The nature reserve rich in titanium, titanium oxide as a semiconductor material used in super capacitor can get decent capacity. And if the graphene oxide composite materials prepared by combining into a new graphene/titania composite materials for supercapacitors will give the corresponding electrochemical properties.By co-precipitation method, this paper were prepared at room temperature with different morphology of micro/nano TiO2 precursor. At 350 ℃,450 ℃,550 ℃ calcination. The use of modified Hummers method during the preparation of graphene successfully load titania precursor. Use titania intercalated into the layers of graphene sheets, solve their agglomeration using graphene with different proportions of the precursor prepared composites. Using scanning electron microscopy (SEM) and X-ray diffraction (XRD) method to physical characterization of its material itself, As with KOH electrolyte, After assemble into super capacitor on the cyclic voltammograms test(CV), constant current charge-discharge test(CP), AC impedance test(EIS), cycle life test, and the electrochemical properties were characterized.The results show that, It has that not been titania precursor and calcined graphene with increasing titania precursor content after the micro-nano composite particle volume decreases and then increases, when the ratio is 1:1 to 0.5A·g-1 current density test, preferably the electrochemical properties, measured obtaining specific capacity 115.56F·g-1, and the cycle of good performance, after 200 cycles capacitors retain 88.4%. Then we will graphene with different temperatures after calcination precursor in a 1:1 ratio of the composite. Increased by scanning electron microscopy and X-ray diffraction test was found that micro particles nano-particles with increasing temperature. Constant current by 0.5 A·g-1 charge and discharge current density test, calculate its assembled supercapacitor specific capacity after 158.5 F·g-1,after 200 cycles, its capacity to maintain the rate was 90.3%. Proved that graphene/titania composite material used in supercapacitor is feasible.