Reversible aqueous Zn battery anode enabled by a stable complexation adsorbent interface

Abstract

Rechargeable aqueous Zn batteries (RAZBs) are highly promising for grid‐scale energy storage systems. Nevertheless, strong water molecule adsorption on Zn electrode provokes undesired corrosion reactions and electrode polarization/dendrite growth, restricting the reversibility of Zn anode and the commercialization of RAZBs. Herein, ethylenediamine tetraacetic acid (EDTA), a typical compounding ingredient, was applied in aqueous ZnSO4 electrolyte to replace the adsorbed water molecules on Zn surface and enabled a stable complexation adsorbent interface. The chemically adsorbed EDTA layer reduced the direct contact between H2O molecules and metallic Zn, and reduced the corrosion rate to more than a half. Moreover, such adsorbent interface featuring abundant oxygen/nitrogen‐based functional groups regulated Zn deposition kinetics and promoted the uniform Zn plating. As consequence, the stable complexation adsorbent interface enabled highly‐reversible Zn stripping/plating behavior for 5000 h under a harsh dynamic measurement that combining eletrochemical cycling at 1 mA cm−2 and 0.5 mAh cm−2 for 72 h and resting for 24 h. The effectiveness of such complexation adsorbent interface was also verified in MnO2||Zn full cells. The complexation interface chemistry demonstrated in this study opened up new avenues for the design of low‐cost and highly reversible Zn metal electrodes towards next‐generation RAZBs.

Semi‐Immobilized Ionic Liquid Regulator with Fast Kinetics toward Highly Stable Zinc Anode under −35 to 60 °C

“…[3,[31][32][33][34][35] Despite excellent protection effects achieved in the anode/electrolyte interface, the interface thermodynamics stability and ion-transport kinetics are still key and urgent issues, especially at high current densities and extreme temperatures. [36][37][38][39][40] Therefore, a stable interface layer with fast ion transport is highly needed to continuously protect the Zn anode with superior rate capability in wide temperature ranges.…”

Hybrid Organic/Inorganic Interphase for Stabilizing a Zinc Metal Anode in a Mild Aqueous Electrolyte

“…Many effective strategies were proposed to enable uniform Zn deposition and inhibit side reactions, , such as designing a Zn micromesh to induce spatial-selection deposition, modifying the electrolyte with a cosolvent to change the solvation structure and form a beneficial solid interface, and constructing electrode–electrolyte interphases to protect zinc from parasitic reactions and regulate Zn 2+ deposition. − …”

“…These processes, including the undesirable hydrogen evolution, substantially reduce the Coulombic efficiency (CE) of ZIBs. 8 Many effective strategies were proposed to enable uniform Zn deposition and inhibit side reactions, 11,12 such as designing a Zn micromesh to induce spatial-selection deposition, 13 modifying the electrolyte with a cosolvent to change the solvation structure and form a beneficial solid interface, 14 and constructing electrode−electrolyte interphases to protect zinc from parasitic reactions and regulate Zn 2+ deposition. 15−17 Among them, fabricating a protective layer is one of the most effective, simple, and direct methods to prevent Zn from directly contacting the electrolyte and possibly regulate Zn deposition.…”

New Type of Dynamically “Solid–Liquid” Interconvertible Electrolyte for High-Rate Zn Metal Battery

“…6−8 In addition, the Zn dendrite would not only enlarge the volume of the anode but also provide more sites for side reactions and corrosion, resulting into extra consumption of Zn metal and electrolyte. 2,9 Therefore, the approach to alleviate dendrites is the crucial part to accelerate the practical application of large-scale ZMBs. Solid electrolytes are mechanically effective to mitigate dendrite growth.…”

“…These classic models both confirm that a high current density can accelerate the formation and subsequent growth of dendrites. This problem of uneven Zn plating along with dendrites growth in high-rate Zn metal batteries (ZMBs, a safe and reliable battery for next generation large-scale commercial energy storage system) is also severe and needs to be solved. , The needlelike or sheetlike dendrites can penetrate the separator and result in sudden failure of the battery because of a short circuit. − In addition, the Zn dendrite would not only enlarge the volume of the anode but also provide more sites for side reactions and corrosion, resulting into extra consumption of Zn metal and electrolyte. , Therefore, the approach to alleviate dendrites is the crucial part to accelerate the practical application of large-scale ZMBs. Solid electrolytes are mechanically effective to mitigate dendrite growth .…”