Fabrication of TiO2-Nanotube-Array-Based Supercapacitors.

Faheem Ahmed,Joohyeon Oh,Abdullah Aljaafari,Adil Alshoaibi,Bon Heun Koo,Hatem Abuhimd,Syed A Pervez

doi:10.3390/mi10110742

Abstract

In this work, a simple and cost-effective electrochemical anodization technique was adopted to rapidly grow TiO2 nanotube arrays on a Ti current collector and to utilize the synthesized materials as potential electrodes for supercapacitors. To accelerate the growth of the TiO2 nanotube arrays, lactic acid was used as an electrolyte additive. The as-prepared TiO2 nanotube arrays with a high aspect ratio were strongly adhered to the Ti substrate. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results confirmed that the TiO2 nanotube arrays were crystallized in the anatase phase. TEM images confirmed the nanotublar-like morphology of the TiO2 nanotubes, which had a tube length and a diameter of ~16 and ~80 nm, respectively. The electrochemical performance of the TiO2 nanotube array electrodes was evaluated using the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge (GCD) measurements. Excellent electrochemical response was observed for the electrodes based on the TiO2 nanotube arrays, as the cells delivered a high specific capacitance of 5.12 mF/cm2 at a scan rate of 100 mV/s and a current density of 100 µA/cm2. The initial capacity was maintained for more than 250 cycles. Further, a remarkable rate capability response was observed, as the cell retained 88% of the initial areal capacitance when the scan rate was increased from 10 to 500 mV/s. The results suggest the suitability of TiO2 nanotube arrays as electrode materials for commercial supercapacitor applications.

Highlights

IntroductionBecause of their special properties including high power density, long cycle life, small size, cost effective, and good reversibility [1,2,3], supercapacitors have become one of the most important and promising energy storage devices
In recent years, because of their special properties including high power density, long cycle life, small size, cost effective, and good reversibility [1,2,3], supercapacitors have become one of the most important and promising energy storage devices
It is clear from the pattern that Fthigeuprere1psahreodwsTitOhe2 XnaRnDotpuabteteranrroafyscrsyhsotawlleindecThiaOr2acntaenriostuicbediafrfracytsi.onIt ipsecalkesarwfrhoimchthweepreatvterny twhaeltlthme aptrcehpeadredwTitihO2 sntanodtaurbde aprartatyesrnshowf eJdCPchDaSrac(t0e1r-i0st8i4c-d12iff8r6a)ctoiofn apneatkassewhTiciOh 2wecreysvtearlsy. wNelol mchaatrcahcetedriwstiitchpsetanksdaorfdapnayttiemrnpuorfitJiCesPDwSer(e01d-e0t8e4c-t1e2d8,6w) ohficahndateamseonTsiOtr2atcersytshtalts.thNe onacnhoartuacbteesrihstaidc pheigahkspohf aasney pimurpiutyr,itiaensdwethree dsehtaercptende,sws hoifchthdeempoeankstsraitnedsitchaatetsthtehneahniogthubcersyhstaadllhinigithy pohfasthe epuTriiOty2, annadnothtuebseharrpanyess.s of the peaks indicates the high crystallinity of the TiO2 nanotube arrays

Summary

Introduction

Because of their special properties including high power density, long cycle life, small size, cost effective, and good reversibility [1,2,3], supercapacitors have become one of the most important and promising energy storage devices. A large surface area and small diffusion paths are required for electrons and ions [10,11,12,13,14,15] to accomplish fast redox reactions To achieve this target, one-dimensional (1D) nanostructures such as nanotubes, nanowires, nanosheets, and mesoporous with controlled size, shape, crystallinity, and chemical composition could be considered. Because of high surface area, good chemical stability, and wide potential window, 1D TiO2 nanotube arrays have largely been used as suitable electrode material for supercapacitors. We synthesized vertically aligned TiO2 nanotube arrays as an electrode material prepared using an electrochemical anodization method with a fast growth rate, high aspect ratio, and strong adherence to the metal surface for supercapacitor applications. The electrochemical performance of the as-prepared electrode was studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and the galvanostatic charge/discharge (GCD) method

Experimental Details

Results and Discussion

Conclusions