Potential-Dependent Passivation of Zinc Metal in a Sulfate-Based Aqueous Electrolyte

Abstract

Owing to its abundance, high theoretical capacity, and low electrode potential, zinc is one of the most important metallic anodes for primary and secondary batteries such as alkaline and zinc–air batteries. In the operation of zinc-based batteries, passivation of the anode surface plays an essential role because the electrode potential of zinc is slightly below that of the hydrogen evolution reaction. Therefore, it is important to scrutinize the nature of the passivation film to achieve anticorrosion inside batteries. Herein, the potential-dependent formation and removal of the passivation film during the deposition and dissolution of zinc metal in aqueous electrolytes are detected via electrochemical quartz crystal microbalance analysis. Film formation was not noticeable in hydroxide-based electrolytes; however, sulfate-based electrolytes induced potential-dependent formation and removal of the passivation film, enabling a superior coulombic efficiency of 99.37% and significantly reducing the rate of corrosion of the zinc-metal anodes. These observations provide insights into the development of advanced electrolytes for safe and stable energy-storage devices based on zinc-metal anodes.

Sustainable high-energy aqueous zinc–manganese dioxide batteries enabled by stress-governed metal electrodeposition and fast zinc diffusivity

“…The formation of the ZSH composite originates from complex decomposition owing to pH changes within the electric double layer near the Zn-metal anode, which is consistent with previous reports. 15,29,30 Moreover, the S2p spectra of X-ray photoelectron spectroscopy (XPS) further verified the long-term existence of ZSH in the composite layer (Fig. 2(d) and Fig.…”

Selection criteria for current collectors for highly efficient anode-free Zn batteries

“…To test this assumption, we used an electrochemical microbalance with dissipation (EQCM-D) technique, which allows in situ monitoring of gravimetric and non-gravimetric phenomena occurring on the electrode surface during the rst Zn electrodeposition and stripping processes. [21][22][23] For comparison, Zn deposition and stripping were investigated on Cu-coated crystal and Au-coated crystal.…”

Interphases in aqueous rechargeable zinc metal batteries

“…12a and b show the schematic diagrams of the setup for EQCM analysis, which is widely used to detect the change in the mass of the electrode during electrochemical processes. According to the Sauerbrey equation (Δ f = − C f Δ m ), 138 there is a linear dependence of characteristic frequency on the mass of the crystal oscillator. The vibrational frequency of the quartz crystal decreases as the weight of the working electrode increases (Fig.…”