In Situ Formed Robust Solid Electrolyte Interphase with Organic-Inorganic Hybrid Layer for Stable Zn Metal Anode.

Stabilizing the Zn anode/electrolyte interface is critical for advancing aqueous zinc ion storage technologies. Addressing this challenge helps minimize parasitic reactions and controls the formation of Zn dendrites, which is fundamental to achieving highly reversible Zn electrochemistry. In this study, 2% by volume of dimethyl sulfoxide (DMSO) is introduced into the baseline zinc sulfate (ZS) electrolyte, which acts as an efficient regulator to form a robust solid-electrolyte interphase (SEI) on the Zn anode. This innovative approach enables uniform Zn deposition and does not substantially modify the Zn2+ solvation structure. The Zn||Zn symmetric cell exhibits an extended cycle life of nearly one calendar year (>8500 h) at a current density of 0.5 mA cm-2 and an areal capacity of 0.5 mAh cm-2. Impressive full cell performance can be achieved. Specifically, the Zn||VS2 full cell achieves an areal capacity of 1.7 mAh cm-2, with a superior negative-to-positive capacity ratio of 2.5, and an electrolyte-to-capacity ratio of 101.4 µL mAh-1, displaying remarkable stability over 1000 cycles under a high mass loading of 11.0 mg cm-2 without significant degradation. This innovative approach in electrolyte engineering provides a new perspective on in situ SEI design and furthers the understanding of Zn anode stabilization.

Dynamic Regulation of the Interfacial pH for Highly Reversible Aqueous Zinc Ion Batteries.

An electrolyte additive, with convenient operation and remarkable functions, has been regarded as an effective strategy for prolonging the cycle life of aqueous zinc ion batteries. However, it is still difficult to dynamically regulate the unstable Zn interface during long-term cycling. Herein, tricine was introduced as an efficient regulator to achieve a pH-stable and byproduct-free interface. The functional zwitterion of tricine not only inhibits interfacial pH perturbation and parasitic reactions by the trapping effect of an anionic group (-COO-) but also simultaneously creates a uniform electric field by the electrostatic shielding effect of a cationic group (-NH2+). Such synergy accordingly eliminates dendrite formation and creates a chemical equilibrium in the electrolyte, endowing the Zn||Zn cell with long-term Zn plating/stripping for 2060 h at 5 mA cm-2 and 720 h at 10 mA cm-2. As a result, the Zn||VS2 full cell under a high cathodic loading mass (8.6 mg cm-2) exhibits exceptional capacity retention of 93% after 1000 cycles.

A smelting-rolling strategy for ZnIn bulk phase alloy anodes.

Reversibility and stability are considered as the key indicators for Zn metal anodes in aqueous Zn-ion batteries, yet they are severely hindered by uncontrolled Zn stripping/plating and side reactions. Herein, we fabricate a bulk phase ZnIn alloy anode containing trace indium by a typical smelting-rolling process. A uniformly dispersed bulk phase of the whole Zn anode is constructed rather than only a protective layer on the surface. The Zn deposition can be regarded as instantaneous nucleation due to the adsorption of the evenly dispersed indium, and formation of the exclusion zone for further nucleation can be prevented at the same time. Owing to the bulk phase structure of ZnIn alloy, the indium not only plays a crucial role in Zn deposition, but also improves the Zn stripping. Consequently, the as-designed ZnIn alloy anode can sustain stable Zn stripping/plating for over 2500 h at 4.4 mA cm-2 with nearly 6 times smaller voltage hysteresis than that of pure Zn. Moreover, it enables a substantially stable ZnIn//NH4V4O10 battery with 96.44% capacity retention after 1000 cycles at 5 A g-1. This method of regulating the Zn nucleation by preparing a Zn-based alloy provides a potential solution to the critical problem of Zn dendrite growth and by-product generation fundamentally.

Spontaneous Construction of Nucleophilic Carbonyl-Containing Interphase toward Ultrastable Zinc-Metal Anodes.

Multifunctional interfacial engineering on the Zn anode to conquer dendrite growth, hydrogen evolution, and the sluggish kinetics associated with Zn deposition is highly desirable for boosting the commercialization of aqueous zinc-ion batteries. Herein, a spontaneous construction of carbonyl-containing layer on a Zn anode (Zn@ZCO) is rationally designed as an ion redistributor and functional protective interphase. It has strong zincphilicity and dendrite suppression ability due to the significant interaction of the highly electronegative and highly nucleophilic carbonyl oxygen, favoring ion transport and homogenizing Zn deposition effectively. On the other side, the hydrogen bond formed by the proton acceptor of oxygen atom in ZCO regulates the Zn-ion desolvation process at the interfaces, thus bounding water activity and then mitigating water-induced parasitic reactions. Consequently, the Zn@ZCO anode exhibits an extended cycling lifespan of 5000 h (>208 days) with a dendrite-free surface and negligible by-products. More encouragingly, the effectiveness is also convincing in NH4 V4 O10 -based full-cells with excellent rate performance and cyclic stability. The stabilized Zn anode enabled by the strategy of spontaneous construction of functional solid electrolyte interphase brings forward a facile and instructive approach toward high-performance zinc-storage systems.

Integrated 'all-in-one' strategy to stabilize zinc anodes for high-performance zinc-ion batteries.

Many optimization strategies have been employed to stabilize zinc anodes of zinc-ion batteries (ZIBs). Although these commonly used strategies can improve anode performance, they simultaneously induce specific issues. In this study, through the combination of structural design, interface modification, and electrolyte optimization, an 'all-in-one' (AIO) electrode was developed. Compared to the three-dimensional (3D) anode in routine liquid electrolytes, the new AIO electrode can greatly suppress gas evolution and the occurrence of side reactions induced by active water molecules, while retaining the merits of a 3D anode. Moreover, the integrated AIO strategy achieves a sufficient electrode/electrolyte interface contact area, so that the electrode can promote electron/ion transfer, and ensure a fast and complete redox reaction. As a result, it achieves excellent shelving-restoring ability (60 hours, four times) and 1200 cycles of long-term stability without apparent polarization. When paired with two common cathode materials used in ZIBs (α-MnO2 and NH4V4O10), full batteries with the AIO electrode demonstrate high capacity and good stability. The strategy of the 'all-in-one' architectural design is enlightened to solve the issues of zinc anodes in advanced Zn-based batteries.