How Solvation Energetics Dampen the Hydrogen Evolution Reaction to Maximize Zinc Anode Stability

Abstract

Aqueous zinc metal batteries (AZMB) are emerging as a promising alternative to the prevailing existing Lithium‐ion battery technology. However, the development of AZMBs is hindered due to challenges including dendrite formation, hydrogen evolution reaction (HER), and ZnO passivation on the anode. Here, a tetraalkylsulfonamide (TAS) additive for suppressing HER, dendrite formation, and enhancing cyclability is rationally designed. Only 1 mm TAS is found that can effectively displace water molecules from the Zn2+ solvation shell, thereby altering the solvation matrix of Zn2+ and disrupting the hydrogen bond network of free water, as demonstrated through 67 Zn and 1H nuclear magnetic resonance spectroscopy, high‐resolution mass spectrometry (HRMS), and density functional theory (DFT) studies. Voltammetry synchronized with in situ monitoring of the electrode surface reveals suppressed dendritic growth and HER in the presence of TAS. Electrochemical mass spectrometry (ECMS) captures real‐time HER suppression during Zn electrodeposition, revealing the ability of TAS to suppress the HER by an order of magnitude. A ≈25‐fold cycle life improvement from ≈100 h to over 2500 h in coin cells cycled in the presence of TAS. Furthermore, by suppressing passivation product formation, it is demonstrated that strategy robustly maximizes the stability of Zn metal anodes.

Tailoring Localized Electrolyte via a Dual-Functional Protein Membrane toward Stable Zn Anodes

“…46 The kinetics associated with Zn nucleation can be analyzed through the Tafel curves derived from the cathodic scanning segment of CV. 47 The related results reveal that the raw ESM corresponds to the lowest exchange current value, signifying suppression of electron-transfer kinetics (Figure S19b). These would jointly allow the deposited Zn to be uniformly and densely distributed over the electrode surface, thereby reducing the likelihood of dendrite formation.…”

“…According to classical nucleation theory, as the nucleation overpotential enlarges, the Zn nucleus radius decreases and the nucleation rate increases during plating . The kinetics associated with Zn nucleation can be analyzed through the Tafel curves derived from the cathodic scanning segment of CV . The related results reveal that the raw ESM corresponds to the lowest exchange current value, signifying suppression of electron-transfer kinetics (Figure S19b).…”