Self-supporting electrodes obtained by electrochemical dealloying of Zr-based metallic glass alloys for energy storage applications

An efficient energy storage device with good cyclic stability and high storage performance requires a conductive electrode that has high strength, high hardness, excellent elasticity, and high corrosion resistance. All these superior mechanical and electrochemical properties are inherent in metallic glass alloys. Unfortunately, using as-prepared metallic glasses is not recommended for energy storage applications due to their small surface area. The dealloying method is usually used to create a porous structure of the material of interest by dissolving the more active components and leaving the nobler components in the material. As a result, this chemical treatment increases the surface area and enhances the storage properties of the dealloyed materials through creating metal ligands and long pore channels. Accordingly, in this study, self-supporting electrodes based on Zr-based metallic glass alloy prepared by electrochemical dealloying were investigated. The amorphous nature of ZrxTi65-xPd25Ag10 (x = 40, 50, and 55 at.%) metallic glasses ribbons was confirmed by X-ray diffraction (XRD) analysis. The surface morphologies of the ribbons before and after electrochemical dealloying were observed by use of a scanning electron microscope (SEM) associated with energy-dispersive X-ray spectroscopy (EDX). The corrosion behavior was investigated in 1-M H2SO4. It appeared that the ribbons revealed excellent corrosion resistance compared to the common 304 stainless steel. It also found that the corrosion rate increases with the increase of zirconium content in the ribbons. The suitability of the dealloyed ribbons as good electrode materials for energy storage applications has been examined by cyclic voltammetry (CV), galvanostatic charge/discharge measurement (GCD), and electrochemical impedance spectroscopy (EIS). The results showed that the specific capacitance, energy density, and power density of the dealloyed ribbons increase with the increase of Zr content, indicating that Zr-rich glassy alloys provide suitable electrode materials for energy storage applications.

Automated summary

An efficient energy storage device requires a conductive electrode with high strength, hardness, elasticity, and corrosion resistance. Metallic glass alloys possess these properties, but their small surface area limits their use. Electrochemical dealloying is used to increase the surface area and enhance storage properties by creating metal ligands and pore channels. In this study, Zr-based metallic glass alloy electrodes prepared by electrochemical dealloying were investigated and shown to have good corrosion resistance and improved storage properties.