Nanocrystalline Pyrochlore La2Sn1.6Zr0.4O7 as a New Candidate for Supercapacitor Electrodes

Nanocrystalline La2Sn1.6Zr0.4O7 is synthesized by microwave assisted combustion method. The phase formation and morphological features of La2Sn1.6Zr0.4O7 are characterized by X-ray. diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), Fourier Transform Infrared (FT-IR) spectrum and Transmission Electron Microscopy (TEM) respectively. XRD pattern shows the formation of cubic Pyrochlore structure of La2Sn1.6Zr0.4O7. FTIR studies attributed the presence of characteristic functional groups of La-O, Sn-O and Zr-O. TEM image reveals that the size of La2Sn1.6Zr0.4O7 particle exhibits from 50 nm to 100 nm and the observed d-spacing from HRTEM is matched well with the XRD d-spacing. The SAED pattern shows the polycrystalline behaviour of La2Sn1.6Zr0.4O7. The room temperature electrical conductivity of La2Sn1.6Zr0.4O7 is 3.12 x 10(-6) S cm(-1). The synthesized La2Sn1.6Zr0.4O7 particle is explored as electrodes for supercapacitor and the performances are studied by cyclic voltammetric and charge discharge studies using 1 M H2SO4 electrolyte. From charge discharge analysis the specific capacitance was found to be 74 Fg(-1) at 1 mA cm(-2). The resistive behaviour of the electrodes is studied through electrochemical impedance spectroscopy. Also the cycling stability is studied by performing the 100 charge discharge cycles. It reveals that there is almost 100% cycling stability is achieved. Hence nanocrystalline La2Sn1.6Zr0.4O7 pyrochlore can have the feasibility as an electrode material for supercapacitor application.