Doped CuCrO2: A possible material for supercapacitor applications

Delafossites, owing to their layered structural characteristics are mostly known for thermoelectric and Lithium ion battery applications. In the present paper we explore the possibility of using such a delafossite oxide viz. CuCrO2 for use as a supercapacitor material. In this regard, multivalent doping at the Cr site of CuCrO2 delafossite compound was carried out to study the effect on its electrochemical properties. The phase formation and morphological studies carried out by X-ray diffraction and Scanning Electron Microscope (SEM) techniques respectively reveal the presence of a single phase of CuCr1-x(MgTi)(x/2)O-2 (x = 0, 0.05, 0.1, 0.15) with appropriate composition. The electrochemical properties of all the compositions were examined by cyclic voltammetry (CV) using a three-electrode system. The CV studies show an increase in specific capacitance with increasing dopant concentration. The increased electrical conductivity with dopant concentration is the reason for enhanced specific capacitance which is supported by the electrochemical impedance spectroscopic studies. The highest doped composition x = 0.15, gave a specific capacitance value of 248 Fg(-1) with the scan rate of 50 mVs(-1) and showed good cycle stability up to 2000 cycles.