In Situ Constructing a Film‐Coated 3D Porous Zn Anode by Iodine Etching Strategy Toward Horizontally Arranged Dendrite‐Free Zn Deposition

Abstract

Zn metal anode has drawn tremendous attention owing to its low cost and high volumetric capacity advantages. However, the commercial application of zinc-based batteries is greatly deterred by Zn dendrite and severe side reactions. Interface modification is one of the most effective strategies to solve these issues. Herein, a facile iodine etching strategy to in situ construct a film-coated 3D porous Zn anode is first proposed, which significantly reduces the nucleation overpotential of Zn while suppressing side reactions, thus resulting in uniform Zn deposition. Benefiting from the dual protection of surface coating and 3D porous Zn anode, the symmetric cell displays a long lifespan of over 5000 h at 1 mA cm -2 , ≈40 times of bare Zn anode. The asymmetric cell with modified Zn anode also delivers excellent cycling stability for over 2000 cycles to achieve a high average Coulombic efficiency of 99.87%. Moreover, the capacity retention of a full battery coupled with ammonium vanadate cathode after 5000 cycles is up to 97.3%, which is much more stable than the bare Zn anode under the same condition (20%). Such a novel interfacial modification method provides a new perspective for the realization of stable metal electrodes.

Regulating zinc deposition behaviors by using a functional PANI modification layer on a separator for high performance aqueous zinc-ion batteries

“…[1][2][3][4] However, the practical application of AZIBs is limited by the following issues, i.e., the undesirable Coulombic efficiency (CE) and poor cycle life caused by the dendrite growth, and side reactions (hydrogen evolution reaction (HER) and corrosion reaction) of a Zn metal anode. 5,6 In the aqueous electrolyte, the distribution of the electrical eld near the commercial Zn foil surface is uneven, which easily leads to the uncontrolled growth of Zn dendrites at protuberance sites because of the "tip effect" during the zinc deposition process. In addition, the corrosion of Zn metal and the competing HER in an aqueous electrolyte are inevitable, which also facilitate the uneven distribution of the electrical eld and irregular dendrite growth.…”

A nuclei-rich strategy for highly reversible dendrite-free zinc metal anodes

“…In this work, we propose nuclei-rich Zn plating as a new strategy to inhibit dendrite formation in Zn anodes. By establishing immediate contact between the Zn surface and hydroxyapatite, which possesses high Zn 0 adsorption energy and Zn 2+ conductivity, a nuclei-incubating interface is constructed to [43][44][45][46][47][48][49][50][51][52][53][54] Red dash lines represent a practically competitive performance target for ZMBs (a cumulative capacity of 10 Ah cm À2 , an ideal CE of 100%, a current density of 10 mA cm À2 , and an areal capacity of 5 mA h cm À2 ). Accordingly, the color red or blue here (d) indicates current densities in the references meeting or below the target.…”

“…(c) Coulombic efficiency of Zn-Cu cells. (d) Summary of published Zn plating/stripping performance with electrode modifications [43][44][45][46][47][48][49][50][51][52][53][54]. Red dash lines represent a practically competitive performance target for ZMBs (a cumulative capacity of 10 Ah cm À2 , an ideal CE of 100%, a current density of 10 mA cm À2 , and an areal capacity of 5 mA h cm À2 ).…”

Research progress on modified Zn substrates in stabilizing zinc anodes

“…Li et al proposed a method for the in situ preparation of film-coated 3D porous Zn anodes by easy iodine etching, which significantly reduced the nucleation overpotential of Zn while suppressing side reactions, thus achieving uniform Zn deposition. 102 Benefiting from the dual protection of the surface coating and the 3D porous zinc anode, the symmetric cell has a service life of more than 5000 hours at 1 mA cm −2 , which is approximately 40 times that of a bare zinc anode (Fig. 4e).…”