Electrochemical performance of a portable asymmetric supercapacitor device based on cinnamon-like La2Te3 prepared 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.