Electrochemical performance of a portable asymmetric supercapacitor device based on cinnamon-like La₂Te₃prepared by a chemical synthesis route

Abstract

A cinnamon-like La2Te3 nanostructure has been prepared by a simple chemical bath deposition (CBD) route. Field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy techniques have been used to characterize the morphological and structural properties of the La2Te3 thin films. The prepared La2Te3 thin film electrodes are applied in a supercapacitor, in which they exhibited a high specific capacitance value of 469 F g−1 at a scan rate of 2 mV s−1 with an excellent cycling performance up to 1000 cycles. Even at a specific power of 2.5 kW kg−1, the La2Te3 electrode possessed a specific energy of ∼126 Wh kg−1. At a relatively high discharge current density of 4 mA cm−2, the specific capacitance was still maintained at 220 F g−1. Furthermore, portable La2Te3 asymmetric supercapacitor devices have been fabricated using an aqueous 1 M KOH electrolyte with good specific energy and specific power. Such an impressive portable asymmetric supercapacitor is a promising candidate for applications in high-performance energy storage systems.