Tannic acid assisted metal–chelate interphase toward highly stable Zn metal anodes in rechargeable aqueous zinc-ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have attracted extensive attention because of their eco-friendliness, intrinsic safety, and high theoretical capacity. Nevertheless, the long-standing Zn anode issues such as dendrite growth, hydrogen evolution, and passivation greatly restrict the further development of AZIBs. Herein, a metal–chelate interphase with high Zn affinity is constructed on the Zn metal surface (TA@Zn) via dipping metallic Zn into a tannic acid (TA) solution to address the aforementioned problems. Benefiting from the abundant hydrophilic and zincophilic phenolic hydroxyl groups of TA molecules, the metal–chelate interphase shows strong attraction for Zn2+ ions, guiding uniform zinc deposition as well as decreasing Zn2+ migration barrier. Therefore, the TA@Zn anode displays an extended lifespan of 850 h at 1 mA cm−2, 1 mAh cm−2 in the Zn|Zn symmetrical cell, and a high Coulombic efficiency of 96.8% in the Zn|Ti asymmetric cell. Furthermore, the Zn|V2O5 full cell using TA@Zn anode delivers an extremely high capacity retention of 95.9% after 750 cycles at 2 A g−1. This simple and effective strategy broadens the interfacial modification scope on Zn metal anodes for advanced rechargeable Zn metal batteries.

A Double‐Charged Organic Molecule Additive to Customize Electric Double Layer for Super‐Stable and Deep‐Rechargeable Zn Metal Pouch Batteries

“…Similarly, according to the nucleation curve (Figure S12, Supporting Information), the NOP in the 2 m ZnSO 4 electrolyte (28 mV) is lower than that with TN (46 mV) at 0.5 mA cm −2 and 0.5 mAh cm −2 , suggesting that the TN enrichment‐HP acts as an electrostatic shield that requires a higher Zn 2+ deposition barrier to initiate Zn nucleation. [ 38 ] Moreover, the distinct Zn deposition patterns in the electrolyte with or without TN can be reflected by the CA curves (Figure 3b). The fast nucleation process with 2D diffusion occurred only within the initial 47 s in the electrolyte with TN additive, and then with the slow growth of current density, which is attributed to the shift to 3D diffusion that always results in preferred [002]‐orientated deposition.…”

A bio-inspired electrolyte with in situ repair of Zn surface cracks and regulation of Zn ion solvation chemistry to enable long life and deep-cycling zinc metal batteries

“…In conventional aqueous electrolytes for AZIBs, due to the poor thermodynamic stability of Zn metal, the Zn corrosion reaction and competitive H 2 evolution are inevitable. 27 However, by utilizing the local pH increase derived from H 2 evolution, a dense and in situ protective lm can be formed and coated on the Zn surface (Fig. S1 †).…”

Zincophilic Design and the Electrode/Electrolyte Interface for Aqueous Zinc‐Ion Batteries: A Review

“…In situ complexing the metal-phytate interphase constructed a zincophilic interface that uniform the nucleation and further deposition of Zn in terms of kinetics. He et al [32] soaked metallic Zn into tannic acid (TA) solution and constructed a metal chelate anode (TA@Zn) with high zincophilicity on the metallic Zn surface (Figure 3g). Taking advantage of the generous hydrophilic and zincophilic phenolic hydroxyl groups of TA, the Zn 2 + are strongly attracted to the metal chelate interlayers, guiding the uniform deposition of zinc and reducing the Zn 2 + migration barriers.…”

“…In situ complexing the metal‐phytate interphase constructed a zincophilic interface that uniform the nucleation and further deposition of Zn in terms of kinetics. He et al [32] . soaked metallic Zn into tannic acid (TA) solution and constructed a metal chelate anode (TA@Zn) with high zincophilicity on the metallic Zn surface (Figure 3g).…”

“…Copyright (2022) Elsevier B.V. g) The Zn deposition process of bare Zn and TA@Zn. Produced with permission from Ref [32]…”