Nanocrystalline Pyrochlore La2Sn1.6Zr0.4 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 diffrac- tion (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 synthe- sized 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.