Redirected Zn Electrodeposition by an Anti‐Corrosion Elastic Constraint for Highly Reversible Zn Anodes

Abstract

With advantages such as high theoretical capacity, low cost, and nontoxicity, Zn metal has been widely investigated as an anode for aqueous batteries. However, the problems of dendrite formation and sustained corrosion originating from severe interfacial side reactions and uncontrolled Zn electrodeposition in aqueous electrolytes significantly slows down the practical application of Zn metal anodes. To address these issues, herein, an anti‐corrosion elastic constraint (AEC) is introduced that is built with nanosized TiO2 and polyvinylidene fluoride (PVDF) matrix to Zn anode, where the PVDF layer serves as an elastic H2O/O2‐blocking layer and the decorated TiO2 nanoparticles assist uniform Zn electrodeposition. With this corrosion‐inhibition and electrodeposition‐redirection coating, the electrodeposition consistency and thermodynamic stability of the Zn anode are significantly improved, enabling a long‐term stable plating/stripping performance for 2000 h with an ultralow overpotential (<50 mV) and a high average Coulombic efficiency (>99.4%) for 1000 cycles without obvious dendrite formation. Even at a high current density of 8.85 mA cm−2 with limited Zn supply (DODZn = 60%), stable Zn deposition is achieved over 250 h. When coupled with a MnO2 cathode, the AEC‐Zn anode shows a remarkably enhanced full‐cell cycling stability, indicative of high reliability of aqueous Zn batteries for practical application.

Fast‐Charging and Ultrahigh‐Capacity Zinc Metal Anode for High‐Performance Aqueous Zinc‐Ion Batteries

“…But it worth noted that the coating can be uniformly deposited at larger current densities (35, 40, 50, and 60 mA cm −2 ) with only 1 min, while it needs a long time of 30 min at a lower current density (20 mA cm −2 ) as depicted in Figure S4, Supporting Information. As shown in Figure S5a, Supporting Information, Nyquist curves for symmetric cells reveal the effect of ZnP coatings prepared at various electrodeposition current densities on Zn 2+ conductivity of Zn‐ZnP anode [ 26 ] and the equivalent circuit is as shown in Figure S6, Supporting Information. As depicted in Figure S5b, Supporting Information, all of the Zn‐ZnP anodes in the symmetric cells exhibit lower interface impendence ( R ct ) compared with the bare Zn anode (1052 Ω).…”

Comprehensive Analyses of Aqueous Zn Metal Batteries: Characterization Methods, Simulations, and Theoretical Calculations

“…Reproduced with permission. [ 91 ] Copyright 2020, Wiley‐VCH. f) XRD patterns of the bare Zn and Al 2 O 3 @Zn after cycling.…”

“…X‐ray diffraction (XRD) was used to further characterize the phase composition and crystal structure of these corrosion byproducts (Figure 4e,f). [ 91,92 ]…”

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

“…designed a polymeric interphase layer composed of polyamide and Zn(TfO) 2 , which can not only regulate Zn deposition, but also protect the surface of the deposited Zn from the electrolyte. [ 16 ] Besides, constructing coating layers including metal–organic frameworks (MOFs), [ 17 ] nanoporous CaCO 3 , [ 18 ] poly(vinyl butyral), [ 19 ] ZnO, [ 20 ] ZnS, [ 21 ] carbon black, [ 22 ] indium‐based compounds [ 23 ] and TiO 2 /PVDF composite [ 24 ] have also been proved to be effective in delaying Zn dendrite formation and improving electrochemical performance. However, these protective layers may be cracked during long‐term cycling especially at high current densities due to the drastic volume change during Zn deposition/stripping.…”