Synergistic Manipulation of Zn²⁺ Ion Flux and Desolvation Effect Enabled by Anodic Growth of a 3D ZnF₂ Matrix for Long‐Lifespan and Dendrite‐Free Zn Metal Anodes

Abstract

Aqueous rechargeable Zn metal batteries have attracted widespread attention due to the intrinsic high volumetric capacity, low cost, and high safety. However, the low Coulombic efficiency and limited lifespan of Zn metal anodes resulting from uncontrollable growth of Zn dendrites impede their practical application. In this work, a 3D interconnected ZnF2 matrix is designed on the surface of Zn foil (Zn@ZnF2) through a simple and fast anodic growth method, serving as a multifunctional protective layer. The as‐fabricated Zn@ZnF2 electrode can not only redistribute the Zn2+ ion flux, but also reduce the desolvation active energy significantly, leading to stable and facile Zn deposition kinetics. The results reveal that the Zn@ZnF2 electrode can effectively inhibit dendrites growth, restrain the hydrogen evolution reactions, and endow excellent plating/stripping reversibility. Accordingly, the Zn@ZnF2 electrode exhibits a long cycle life of over 800 h at 1 mA cm−2 with a capacity of 1.0 mAh cm−2 in a symmetrical cell test, the feasibility of which is also convincing in Zn@ZnF2//MnO2 and Zn@ZnF2//V2O5 full batteries. Importantly, a hybrid zinc‐ion capacitor of the Zn@ZnF2//AC can work at an ultrahigh current density of ≈60 mA cm−2 for up to 5000 cycles with a high capacity retention of 92.8%.

Stacked Lamellar Matrix Enabling Regulated Deposition and Superior Thermo‐Kinetics for Advanced Aqueous Zn‐Ion System under Practical Conditions

“…An important factor for aqueous Zn-ion battery with modified anode is the negative/positive capacity ratio (N/P) which can evaluate the merits of anode coating and the corresponding application potential of full cells more persuasively. Notably, although the actual areal capacity of the cathodes (PA and 3D ZnF 2 as the protective layers for anodes) used in the full cells are higher than that of our work, [8,29] the calculated N/P from the data in Table S6, Supporting Information, are obviously at a disadvantage (4.45 and 23.3, respectively) compared with a SLM-Zn|AC hybrid supercapacitor.…”

“…Consequently, designing SEI with 3D stacked structure to cast off these dilemmas is very necessary, and it can also overcome the problems of the increased specific surface area and aggravated corrosion caused by a traditional 3D structure. [28,29] Based on the fact that sulfonate anions can induce a flat hexagonal-like Zn (002) texture during electrodeposition, [30] we creatively propose that (002) textured Zn can act as the structural carrier to further synthesize the stacked lamellar matrix (SLM) on zinc anode composed of ZnF 2 /Zn 3 (PO 4 ) 2 /CF X (x = 1 or 3) via simple chemical/electrochemical reactions in 0.5 m zinc trifluoromethanesulfonate (Zn(OTf) 2 )-trimethyl phosphate (TEP) solution. It is noting that we have identified that ZnF 2 possessing high binding energy with the Zn 2+ ion shows great potential in the kinetics of de-solvation process, while Zn 3 (PO 4 ) 2 delivers an excellent thermodynamic stability and anti-corrosion property in restraining the side reactions.…”

Encapsulation of Metallic Zn in a Hybrid MXene/Graphene Aerogel as a Stable Zn Anode for Foldable Zn‐Ion Batteries

“…During the first plating, the stable F-based functional groups would considerably improve uniform nucleation. [8,22] Meanwhile, the presence of CTiO x and TiO 2−x F x bonds was confirmed in high-resolution XPS spectra of the O 1s and Ti 2p (Figure S2, Supporting Information), which can be attributed to the strong contacts between the O-containing RGO and MXene flakes. [21,23] Based on these findings, it's fair to assume that following the hydrothermal process, hydrogen bonding exists between the RGO and MXene flakes.…”

Zinc Anode for Mild Aqueous Zinc-Ion Batteries: Challenges, Strategies, and Perspectives

“…In addition to organic materials, some inorganic materials can also interact strongly with Zn 2+ ions, which has a similar effect on concentration field adjustment. For example, a three-dimensional (3D) interconnected ZnF 2 matrix could be obtained by electrodeposition in NH 4 F aqueous solution [ 67 ]. Compared to bare Zn mental, the ZnF 2 matrix exhibits stronger Coulomb attraction for Zn 2+ ions.…”

“… Copyright 2020, Elsevier. f Schematic illustration of the Zn@ZnF 2 electrode [ 67 ]. Copyright 2020, Wiley–VCH …”