Lotus Effect Inspired Hydrophobic Strategy for Stable Zn Metal Anodes

Abstract

The Zn‐ion batteries (ZIBs) have long suffered from the unstable Zn metal anode, which faces numerous challenges concerning dendrite growth, corrosion and hydrogen evolution reaction. The absence of H2O adsorption control techniques has become a bottleneck for the further development of ZIBs. Using the stearic acid (SA)‐modified Cu@Zn (SA‐Cu@Zn) anode as example, we herein illustrate how the lotus effect controls the H2O adsorption energy on Zn metal anode. The in‐situ integrated Cu nanorods arrays and hydrophobic long‐chain alkyl groups have been constructed, which provide zincophilic ordered channels and hydrophobic property. Consequently, the SA‐Cu@Zn anode exhibits long‐term cycling stability over 2000 h and high average Coulombic efficiency of 99.83% at 1 mA cm−2 for 1 mAh cm−2, which has improved the electrochemical performance of Zn||V2O5 full cell. DFT calculations combined with water contact angle measurements demonstrated that the SA‐Cu@Zn exhibits larger water contact angle and weaker H2O adsorption than Zn. Moreover, the presence of Cu ensures the selective adsorption of Zn on the SA‐Cu@Zn anode, well explaining how excellent reversibility has been achieved. This work demonstrates the effectiveness of the lotus effect on controllable H2O adsorption and Zn deposition mechanism, offering a universal strategy for achieving stable ZIBs anode.This article is protected by copyright. All rights reserved

In Situ Construction of a Hydrophobic Honeycomb-like Structured ZnMoO4 Coating Applied for Enhancing Zinc Anode Performance

“…The results of the plating/stripping cycle stability of the Zn@ZMO symmetrical cell compared with other reported hydrophobic Zn anodes are shown in Figure 4c. 28,29,31,32,42,57 For example, compared with the Zn@ZIF8 anode, which uses organic compounds to modify the Zn anode, at the same current density and areal capacity, the cycle life of Zn@ZMO is almost twice that of Zn@ZIF8. This shows superior plating/stripping cycle stability effects of Zn@ZMO, which can be attributed to the efficient Zn 2+ transport and controlled nucleation of the ZnMoO 4 coating.…”

“…26 Therefore, some researchers tried to construct a hydrophobic layer to protect the zinc anode. To date, a series of hydrophobic coatings have been used to modify zinc anodes, including Zn x -diethylenetriaminepenta-(methylene phosphonic acid) (Zn x -DTPMP), 27 zeolite imidazole framework-8 (ZIF-8), 28 stearic acid-modified Cu@ Zn (SA-Cu@Zn), 29 polyvinylidene fluoride (PVDF) and Santa Barbara Amorphous-15 (PVDF-SBA15), 30 PVDF and acrylic acid, 31 perfluoropolyether (PFPE), 32 etc. Generally, long-chain alkanes or fluorine-containing compounds with low surface energy are preferred to form a hydrophobic layer on the metal base.…”

Aqueous MnO2/Mn2+ electrochemistry in batteries: progress, challenges, and perspectives

“…20,24 In contrast, Zn anode exhibits low redox potential (−0.76 V vs. SHE), high specific capacity (820 mA h g −1 ), excellent reversibility and compatibility in aqueous electrolyte; thus, MnO 2 -based batteries with Zn as anode have been extensively developed and studied. 25,26 During the in-depth investigation of the reaction mechanism, the emerging MnO 2 dissolution/deposition chemistry was proposed and confirmed.…”

Artificial Hydrophilic Organic and Dendrite-Suppressed Inorganic Hybrid Solid Electrolyte Interface Layer for Highly Stable Zinc Anodes

“…Lithium-ion batteries (LIBs) are prevalent in green energy storage devices, such as portable devices and electric vehicles, due to their high energy density and good rechargeability. , However, lithium ore resources are scarce, and the inherent price is high. − Lithium-ion batteries use toxic and flammable organic electrolytes, which have potential safety hazards and are easy to cause environmental pollution, which seriously hinders their further application in the field of energy storage. − It is urgent to develop new batteries to replace lithium-ion batteries. − Aqueous zinc -ion batteries (AZIBs) are considered to be a reliable alternative to LIBs. It shows a high safety characteristic due to their use of aqueous electrolytes. − However, aqueous zinc-ion batteries have poor energy density and cycle life due to side reactions, such as dendrite growth, hydrogen evolution reaction (HER), and corrosion, as well as low zinc utilization (often referred to as depth of discharge, DOD) and undesired Coulombic efficiency (Scheme a). − Addressing these issues, particularly improving the reversibility of zinc metal, is crucial for enhancing the performance of aqueous zinc metal batteries. − …”