Interfacial Molecule Engineering for Reversible Zn Electrochemistry

Abstract

The unstable Zn interface caused by undesired dendrites and parasitic side reactions greatly impedes the deployment of aqueous Zn metal batteries. Herein, an efficient adsorptive additive strategy is proposed to reshape the electric double layer and regulate Zn interfacial chemistry. 2-Hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) was selected owing to its strong adsorption ability, intermolecular hydrogen bonding, and exposed strong electronegative carbonyl group. The constructed self-adaptive adlayer contributes to a localized H 2 O, SO 4 2− -poor environment and horizontal alignment of Zn deposits along the (002) plane, thus endowing thermodynamically stable and highly reversible Zn electrochemistry. As a result, reversible plating/stripping of 3800 h and high Coulombic efficiency of 99.8% are achieved. Intriguingly for practical application, the economical additive (0.016 USD L −1 ) enables stable discharge output for 500 cycles in Zn/VS 2 cells at a low negative-to-positive capacity ratio of 2.5 (cathode mass loading: 10.8 mg cm −2 ), holding great promise for use in a scalable, low-cost, rechargeable battery.

Maximizing Electrostatic Polarity of Non‐Sacrificial Electrolyte Additives Enables Stable Zinc‐Metal Anodes for Aqueous Batteries

“…Figure 3f and Figures S11–S15 compare the EDLCs of electrolytes with different saccharide additives. The results show that adding saccharide additives with larger electrostatic polarity can reduce the EDLC value more effectively, corresponding to a higher adsorption layer coverage [77,78] . This provides a better isolation between water molecules and Zn electrode, and consequently a better inhibition of side reactions.…”

“…The results show that adding saccharide additives with larger electrostatic polarity can reduce the EDLC value more effectively, corresponding to a higher adsorption layer coverage. [77,78] This provides a better isolation between water molecules and Zn electrode, and consequently a better inhibition of side reactions. In addition, corrosion currents of the Zn electrode in different electrolytes were measured.…”

Atomic Pinning of Trace Additives Induces Interfacial Solvation for Highly Reversible Zn Metal Anodes

“…The reaction occurs almost exclusively in the anode–electrolyte interface zone (about a few angstroms). , High additives imply higher costs, and excessive solvation sheaths lead to increased polarization, thus increasing the potential risk of the HER. Unfortunately, the mechanism of action of trace additives at the interface remains a mystery, although some trace additives (a few millimoles or less) have been researched. − Taking the coin cell as an example, the number of atoms in the surface layer of a commonly used 1 cm 2 Zn foil is 1.5 × 10 15 , which is only equivalent to the number of additive molecules in 1.0 μL of CYC-Na solution at a concentration of 0.5 g L –1 , whereas the electrolyte used in each cell can be as much as 100–200 μL. Taking into account the spatial potential resistance of the molecules, the gap between them will only be even more drastic.…”

A mini review on metal–organic framework-based electrode materials for capacitive deionization

“…[52][53][54][55][56][57][58][59][60][61][62] In the past, we have consistently pushed the boundaries in the development of numerous advanced materials with remarkable efficacy in energy and environmental applications. [63][64][65][66] Therefore, in this article, we explore the nature of MOF-derived materials and analyze whether the purported advantages of MOFs can be systematically linked to enhanced CDI performances.…”