Attenuating Water Activity Through Impeded Proton Transfer Resulting from Hydrogen Bond Enhancement Effect for Fast and Ultra‐Stable Zn Metal Anode

Abstract

The high activity of water molecules induces notorious side reactions that seriously impair the stability of the Zn metal anode. Inspired by the mechanism of proton transfer in an aqueous solution, ectoine (ET) with a kosmotropic effect is first introduced into the typical aqueous electrolyte of aqueous zinc‐ion batteries (ZIBs). The hydrogen bond enhancement brought by the ET additive increases the energy barrier for the reconfiguration of hydrogen bonds, thereby impeding the hopping transport of protons based on the Grotthuss mechanism. The inhibited hydrogen evolution reaction (HER) by impeded proton transfer is strongly proved by in situ electrochemical gas chromatography (EC‐GC). The distinctive hydrogen bond enhancement effect of ET results in remarkably improved Zn anode stability while maintaining fast reaction kinetics. Consequently, the Zn//Zn symmetric cell delivers an ultra‐long cycle life of 5700 h 1 mA cm−2/1 mAh cm−2 and 2000 h at 5 mA cm−2/5 mAh cm−2 with lower voltage hysteresis, extending a cycling life by >27 and 24 times without sacrificing reaction kinetics.

Modulating Interfacial Hydrogen-Bond Environment by Electrolyte Engineering Promotes Acidic CO2 Electrolysis

“…According to the Grotthuss mechanism, the proton transfer in an aqueous solution occurs via a series of proton-involved reactions that accompany the migration of topological defects in the H-bond network. ,− Therefore, by breaking and/or reshaping the original H-bond network, the proton transfer and hydrogen-related reaction kinetics can be regulated. ,, In the field of aqueous zinc batteries, several effective and low-cost additives have been utilized to decrease the side reactions associated with water by regulating the H-bond environment among water molecules. − Among these, sulfonate-based molecules are a common type of H-bond acceptors that can modulate the H-bond environment through H-bond interaction between–SO 3 – (the H-bond acceptor) and water (the H-bond donor). Examples of such molecules include sodium dodecyl sulfate (SDS) and sodium dodecyl benzenesulfonate (SDBS) .…”

Bio-inspired hydroxyl-rich electrolyte additive for highly reversible aqueous Zn-ion batteries with strong coordination chemistry

“…12 These defects are strongly correlated with the presence of the Zn 2+ solvated hydration shell [Zn(H 2 O) 6 ] 2+ , leading to the sluggish Zn 2+ redox reaction kinetics and further generating grievous Zn dendrites. [13][14][15] In addition, the presence of a substantial amount of active H 2 O at the interface between the electrolyte and Zn anode during the plating process can intensify hydrogen evolution reactions due to its higher potential (−0.296 V vs. SHE at pH = 5) for hydrogen generation, 16 which causes the drastic fluctuation of the pH value in the local areas of the Zn anode and ultimately drives the formation of irreversible byproducts and severe Zn corrosion. 17 To address the above issues, the central principle is to enhance the deposition kinetics and restrain H 2 O reactivity.…”

Hydrophilic and nanocrystalline carbon quantum dots enable highly reversible zinc-ion batteries

“…7,8 However, lithium batteries have always had the problem of safety hazards and environmental pollution. 9,10 It is of great significance to explore a new generation of safe and environmentally friendly rechargeable batteries.…”