Porous Titanium Oxide Nanotube Arrays / Polyaniline Composite Electrode Preparation And Application Of The Hybrid Capacitor

In this paper, polyaniline is in situ electrochemical polymerized in TiO2nanotube arrays prepared by anodic oxidation to prepare composite electrode of electrochemical capacitors, and tested its electrochemical properties. Matched with the electrode of tantalum electrolytic capacitor to prepare electrolytic-electrochemical hybrid capacitors, and studied the performance of the hybrid capacitor. It was found that the polyaniline/TiO2nanotube arrays composite electrode has electrochemical activity in a neutral electrolyte after treatment.A hybrid capacitor with high energy density and high working voltage, consisting of the anode electrode of tantalum electrolytic capacitor and the cathode electrode of polyaniline/TiO2nanotube arrays, was developed successfully. The PANI/TiO2nanotube arrays composite electrode as the capacitor cathode was prepared by in situ electrochemical polymerization of aniline in porous anodic titania nanotube arrays on titanium foil substrates. The composites electrode showed good rate capability with a specific capacitance of10mF·cm-2while a high power density of0.55mW·cm-2was obtained. Employing a dielectric coated anode electrode, the single-cell hybrid capacitor could withstand high working voltages as high as100V. Because the PAN1/TiO2composite cathode requires little volume due to its high specific capacitance, available space can be used to enlarge the anode electrode, leading to an increase in specific capacitance of the hybrid capacitor. The as-prepared hybrid capacitor exhibited a volumetric energy density of1.11J·cm-3and a gravimetric energy density of0.12J·g-1, which was about four times and three times higher than that of a tantalum electrolytic capacitor, respectively. Short circuit charge-discharge cycle test for the hybrid capacitor at100V demonstrated that its capacitance did not decrease and ESR did not increase after10000cycles, showing excellent cycle stability and power performance. Its peak power density of847.5W·g-1due to a short circuit discharge can be estimated. In addition, electrochemical impedance spectroscopy data indicated that the hybrid capacitor also had good impedance characteristics and frequency characteristics.The polyaniline/TiO2nanotube arrays composite electrode owns electrochemical activity and excellent cycle stability in neutral electrolyte such as PBS buffer solution and CP-120organic neutral solution after electrochemical reduction mixed treatment in NH4Cl solution. Obviously, it greatly expanded the range of applications of polyaniline. Studied the application of this composite electrode in biosensor. Found that it can sensitively detect the ascorbic acid.