In Situ Electrochemically‐Bonded Self‐Adapting Polymeric Interface for Durable Aqueous Zinc Ion Batteries

Abstract

The implementation of aqueous zinc ion batteries (AZBs) is hindered by the notorious Zn dendrite growth and side reactions on Zn anodes. Herein, a novel strategy is introduced to overcome these hurdles by designing a self‐adapting soft polymeric composite interface (SAP). Unlike conventional methods relying on passive coating process, the approach leverages dynamic in situ electrochemical bonding via Zn─O interactions formed during cycling, ensuring intimate contact between the SAP interface and Zn electrode. The SAP interface boasts a robust network of hydrogen bonding and electrostatic interactions, which not only promotes the desolvation of Zn2+ and the repulsion of SO42−, facilitating uniform and rapid Zn2+ migration while effectively suppressing parasitic reactions; but also exhibits remarkable self‐adapting and self‐healing capabilities, enabling the interface to accommodate volume changes and repair mechanical failures over prolonged cycling. Consequently, highly reversible Zn electrodes are achieved with SAP, showcasing 3300 h at 1 mA cm−2/0.5 mAh cm−2 and 350 h at 20 mA cm−2/10 mAh cm−2 in the symmetric cells. The advantages of the SAP interface are further verified when paired with high mass loading LiMn2O4 cathodes in AZBs. The versatile SAP interface offers insights into advanced interface design for efficient and durable AZBs.

Ultrathin Reed Membranes: Nature's Intimate Ion‐Regulation Skins Safeguarding Zinc Metal Anodes in Aqueous Batteries

“…Compared with the O1s XPS spectrum of the pristine reed membrane, which displays the characteristic cellulose bond, C─O bond at 532.5 V, the XPS analysis of the cycled reed interlayer attached to the Cu side reveals the characteristic peak of Zn─O bond at ≈532.1 V, with an increasing relative content of Zn─O bond observed throughout the cycling process. [32,53] Additionally, the Zn 2p XPS spectrum of the reed interlayer cycling for 20 and 50 cycles also exhibits corresponding Zn─O bonds and a rising trend in their content, indicating the occurrence of electrochemical interaction between the reed membrane and Zn electrode. This interaction facilitates intimate and strong adhesion between the reed interlayer and the electrode, promoting the uniform Zn 2+ flux and compact Zn deposition and acting as a protective barrier against dendrite penetration.…”

“…To demonstrate the impact of the reed interlayer on ion regulation and the Zn electrodeposition process, COMSOL simulations were employed to investigate how the structure of the reed membrane influences the current density distribution and the Zn deposition morphology. [32,51] As depicted in Figure 2a, the current density distribution is notably uneven, and the electric field intensity varies more rapidly and is higher near the tip position in the absence of a reed interlayer, attributed to the "tip effect". [52] However, the introduction of a reed membrane with flat multilayered ion transport channels results in an increased uniformity of the current density distribution.…”

Organic solid–electrolyte interface layers for Zn metal anodes

“…4(a)). 85 The polyvinyl alcohol (PVA) networks provide an elastic polymer framework, while the hydroxyl (–OH) and carboxyl (–COOH) groups on the supramolecular components enable robust hydrogen bond interactions within the polymer network, contributing to its self-healing and self-adapting properties. This multifunctional interfacial layer shows intimate contact with Zn due to the formation of Zn–O bonds, remaining effective under elevated current densities and areal capacities.…”

“…Consequently, there has been a growing interest among researchers in exploring multicomponent polymers, which combine two or more polymer types to potentially overcome these limitations. [85][86][87] For instance, Zhang et al fabricated a multicomponent self-adapting interface consisting of an elastic polymer network (polyvinyl alcohol), supramolecular components (citric acid and cyclodextrin), and conductive polymers (PEDOT&PSS) (Fig. 4(a)).…”

In‐Situ Spontaneous Electropolymerization Enables Robust Hydrogel Electrolyte Interfaces in Aqueous Batteries

“…This inherent similarity offers insights into the electrochemical synthesis of polymers and hydrogels. [31][32][33][34] Herein, we successfully achieve an in situ electropolymerization strategy for hydrogel preparation, involving the conversion of precursor solutions into hydrogel electrolytes through in situ spontaneous electropolymerization during batteries cycle operations (Scheme 1c). The electrochemical reaction at the interface generates free radicals, eliminating the need for additional initiators to the precursor solution.…”