Preparation and Electrochemical Performance of Hematite (α-Fe2O3) Nanoparticles as Supercapacitor Electrode Material

As a new class of energy storage devices, supercapacitors display the desirable characteristics of high power density (ten times more than batteries), fast rates of charge–discharge (with seconds),excellent cycling stability, and low maintenance cost, which make them one of the mostpromising candidates for next-generation power devices [1–3]. Unfortunately, the energy storage density of existing supercapacitors is limited, generally one order of magnitude lower than that ofbatteries [4]. Currently, for practical applications, it is essential to increase the energy density ofsupercapacitors, without sacrificing the device power density and cycle life. Experimental evidence suggests that electrode materials play a key role in the development of highperformance supercapacitors. Among various supercapacitor electrode materials, pseudocapacitive transition-metal oxides and electronically conducting polymers based on faradic redoxcharges to rage have exhibited much higher energy density than that of electrochemical doublelayercapacitive carbon materials [5–7]. Among various metal oxides, iron oxides has attracted great attention due to its low cost and environmentally benign nature [5]. In this work, we report on the electrochemical synthesis of α-Fe2O3 nanoparticles via cathodicelectrodeposition route. The prepared nanoparticles were characterized by XRD, IR and SEMtechniques. Their electrochemical properties was also evaluated by cyclic voltammetry, galvanostatic charge–discharge cycling and electrochemical impedance spectroscopy tests. Fig. 1 showed the CV and CP curves of the prepared α-Fe2O3 electrode in 0.5 M Na2SO3. The specific capacitance of the prepared α-Fe2O3 was calculated at a scan rate of 2 mV s−1. Also, thecapacitance retention after 1000 cycles is about 92 % of the initial capacitance at a current density of 1 A g−1. The high capacitance as well as stability of α-Fe2O3 electrode is attributed to its large surface area and fine particle morphology. As iron oxides are inexpensive, the synthetic route adopted for α-Fe2O3 in the present study is convenient and the SC is high with good cycling stability, the α-Fe2O3 nanoparticles have a potential material for supercapacitors

کلیدواژه ها:

α-Fe2O3 ، Electrochemical synthesis ، Nanoparticles ، Supercapacitors