Stable Zinc Research Articles

Stable Zinc Electrode Reaction Enabled by Combined Cationic and Anionic Electrolyte Additives for Non-Flow Aqueous Zn─Br2 Batteries.

Aqueous zinc-bromine batteries hold immense promise for large-scale energy storage systems due to their inherent safety and high energy density. However, achieving a reliable zinc metal electrode reaction is challenging because zinc metal in the aqueous electrolyte inevitably leads to dendrite growth and related side reactions, resulting in rapid capacity fading. Here, it is reported that combined cationic and anionic additives in the electrolytes using CeCl3 can simultaneously address the multiple chronic issues of the zinc metal electrode. Trivalent Ce3+ forms an electrostatic shielding layer to prevent Zn2+ from concentrating at zinc metal protrusions, while the high electron-donating nature of Cl- mitigates H2O decomposition on the zinc metal surface by reducing the interaction between Zn2+ and H2O. These combined cationic and anionic effects significantly enhance the reversibility of the zinc metal reaction, allowing the non-flow aqueous Zn─Br2 full-cell to reliably cycle with exceptionally high capacity (>400mAh after 5000 cycles) even in a large-scale battery configuration of 15×15cm2.

Blocking the Passivation Reaction via Localized Acidification and Cation Selective Interface Towards Highly Stable Zinc Anode

The variations of pH triggers either the formation of zinc sulfate hydroxide (ZSH) or the hydrogen evolution reaction (HER), leading to unsatisfactory zinc anode efficiency. In order to establish a balanced approach that suppresses the HER while creating an acidic environment to eliminate ZSH formation, this study introduces an environmentally friendly chelating additive, tetrasodium iminodisuccinate (IDS), into the ZnSO4 electrolyte. This additive serves to generate a localized acidic environment and a cation-selective surface barrier. The preferentially adsorbed IDS anions create a water-poor interface and engage in synergistic regulation of cation and anion via electrostatic effects, promoting smooth Zn deposition and reducing by-product formation. Additionally, IDS can strongly interact with Zn2+ and adapt to pH variations, thereby providing a stable environment that mitigates side reactions. Unlike sacrificial additives, IDS demonstrates stability under test conditions, resulting in a truly reversible and stable electrolyte system. The implementation of this multifunctional additive results in a prolonged lifespan of metallic Zn, reaching 2548 hours, and a promoted coulombic efficiency of 99.5%. Furthermore, the improved stability of Zn anodes is observed in Zn//LiFePO4 cells, exhibiting the capacity retention of 97.0% over 800 cycles. This strategy opens up a new pathway for enhancing the stability and reversibility of Zn anodes.

Boric acid-induced preferential deposition of (002) plane for highly stable zinc anode

Aqueous zinc-ion batteries (ZIBs) hold significant promise in the future energy storage market. However, the uncontrolled growth of zinc dendrites and the occurrence of side reactions severely constrain the practical deployment of ZIBs. To address these challenges, this study suggests incorporating H3BO3 (HBO) as an electrolyte additive into the ZnSO4 electrolyte, with the aim of inducing preferential growth of the (002) plane. HBO molecules selectively adsorb onto the (100) and (101) planes of zinc, promoting the deposition of Zn2+ ions into the (002) plane and resulting in the formation of a uniformly deposited layer while concurrently inhibiting side reactions. The results demonstrate that ZnǁZn symmetric batteries, with the HBO additive, exhibit stable cycling at high current density, achieving a cycling life of 1100 h at 10 and 10 mAh cm−2 as well as 250 h at 50% depth of discharge. Furthermore, the ZnǁVO2 coin cell demonstrates stable cycling for 1700 cycles at 1 A g−1 and 7000 cycles at 5 A g−1. This study presents a promising case for the commercialization of advanced ZIBs.

Induced Anionic Functional Group Orientation-Assisted Stable Electrode-Electrolyte Interphases for Highly Reversible Zinc Anodes.

Dendrite growth and other side-reaction problems of zinc anodes in aqueous zinc-ion batteries heavily affect their cycling lifespan and Coulombic efficiency, which can be effectively alleviated by the application of polymer-based functional protection layer on the anode. However, the utilization rate of functional groups is difficult to improve without destroying the polymer chain. Here, a simple and well-established strategy is proposed by controlling the orientation of functional groups (─SO3H) to assist the optimization of zinc anodes. Depending on the electrostatic effect, the surface-enriched ─SO3H groups increase the ionic conductivity and homogenize the Zn2+ flux while inhibiting anionic permeation. This approach avoids the destruction of the polymer backbone by over-sulfonation and amplifies the effect of functional groups. Therefore, the modified sulfonated polyether ether ketone (H-SPEEK) coating-optimized zinc anode is capable of longtime stable zinc plating/stripping, and moreover an enhanced cycling steadiness under high current densities is also detected in a series of Zn batteries with different cathode materials, which achieved by the inclusion of H-SPEEK coating without causing any harmful effects on the electrolyte and cathode. This work provides an easy and efficient approach to further optimize the plating/stripping of cations on metal electrodes, and sheds lights on the scale-up of high-performance aqueous zinc-ion battery technology.

A Chemical Sewing Enabled All‐In‐One Control Interface for Robust Zinc Metal Anodes

AbstractDeveloping artificial protective layers is an effective strategy to address the issue of dendrites for aqueous Zn‐metal batteries (ZMBS). However, drawbacks such as rough microscopic morphology, excessive thickness, and single functionality remain, limiting the attainment of a stable zinc anode. Herein, a novel multifunctional organic–inorganic hybrid artificial protective layer is produced by splicing inorganic fragments onto organic materials in situ using a chemical sewing. The protective layer is well‐compatible and also retains the function of organic and inorganic materials, which not only inhibits dendrite production but also alleviates Zn corrosion. The Si─OH bond of the zincophilic group enables planar Zn deposition while forming hydrogen bonds with water, suppressing water activity near the anode and reducing the hydrogen evolution reaction. As expected, the Zn||Zn symmetric cell with a protective layer provides high cycling stability of more than 1960 h at 1 mA cm−2, which is about 28 times higher than that of the symmetric cell assembled without the protective layer. More importantly, a Zn||V2O5 full cell with an ultra‐long lifetime has been achieved with an artificial protective layer. This work provides a potential viable path to achieve long‐lived ZMBS.

A Multifunctional Additive Based on the Cation-Anion Synergistic Effect for Highly Stable Zinc Metal Anodes.

The Zn dendrite and hydrogen evolution reaction have been a "stubborn illness" for the life span of zinc anodes, which significantly hinders the development of aqueous zinc batteries (AZBs). Herein, considering the ingenious molecular structure, a multifunctional additive based on the synergistic regulation of cations and anions at the interface is designed to promote a dendrite-free and stable Zn anode. Theoretical calculations and characterization results verified that the electrostatic shield effect of the cation, the solvation sheath structure, and the bilayer structural solid electrolyte film (SEI) jointly account for the uniform Zn deposition and side reaction suppression. Ultimately, a remarkably high average Coulombic efficiency (CE) of 99.4% is achieved in the Zn||Cu cell for 300 cycles, and a steady charge/discharge cycling over 3000 and 300 h at 1.0 mA cm-2/1.0 mAh cm-2 and 10 mA cm-2/10 mAh cm-2 is obtained in the Zn||Zn cell. Furthermore, the assembled full battery demonstrates a prolonged cycle life of 2000 cycles.

One-stone, two birds: One step regeneration of discarded copper foil in zinc battery for dendrite-free lithium deposition current collector

The ever-growing requirement for electrochemical energy storage has exacerbated the production of spent batteries, and the recycling of valuable battery components has recently received a remarkable attention. Among all battery components, copper foil is widely utilized as a current collector for stable zinc platting and stripping in zinc metal batteries (ZMBs) due to the perfect lattice matching of between metal copper and zinc, which is accompanied by the formation of multiple copper-zinc alloy components during the cycling process. Herein, a novel “two birds with one-stone” strategy through a one simple heat treatment step to revive the discarded copper foil in zinc metal battery is reported to further obtain a lithiophilic current collector (CuxZny-Cu) with multiple copper-zinc alloy components on the surface of the discarded copper foil. Such revived CuxZny-Cu current collector greatly reduces the lithium nucleation overpotential and realizes uniform lithium deposition and further inhibits lithium dendrites growth. The formed multiple CuxZny alloy phases on the surface of discarded copper foil exhibit a low Li nucleation overpotential of only 15 mV at 0.5 mA cm−2 for the first cycle. Moreover, such a CuxZny-Cu current collector could achieve stable cycle for 220 cycles at 0.5 mA cm−2 and 110 cycles at 1 mA cm−2 with a Li plating capacity of 1 mAh cm−2. Theoretical calculations indicate that, compared with pure Cu foil, the formed multiple alloy components of CuZn5, CuZn8, Cu0.61Zn0.39 and CuZn have low adsorption energy of −2.17, −2.55, −2.16 and −2.35 eV with lithium atoms, respectively, which result in reduced lithium nucleation overpotential. The full cell composed of CuxZny alloy current collector with deposition of 5 mAh cm−2 metal Li anode coupled with LiFePO4 (LFP) cathode exhibits a reversible capacity of 125.6 mAh/g after 110 cycles at a current of 0.5 C with capacity retention of 85.1 %. This work proposed a promising strategy to regenerate the discarded copper foil in rechargeable batteries.

Stable Zinc Anode Facilitated by Regenerated Silk Fibroin-modified Hydrogel Protective Layer.

Inherent dendrite growth and side reactions of zinc anode caused by its unstable interface in aqueous electrolytes severely limit the practical applications of zinc-ion batteries (ZIBs). To overcome these challenges, a protective layer for Zn anode inspired by cytomembrane structure is developed with PVA as framework and silk fibroin gel suspension (SFs) as modifier. This PVA/SFs gel-like layer exerts similar to the solid electrolyte interphase, optimizing the anode-electrolyte interface and Zn2+ solvation structure. Through interface improvement, controlled Zn2+ migration/diffusion, and desolvation, this buffer layer effectively inhibits dendrite growth and side reactions. The additional SFs provide functional improvement and better interaction with PVA by abundant functional groups, achieving a robust and durable Zn anode with high reversibility. Thus, the PVA/SFs@Zn symmetric cell exhibits an ultra-long lifespan of 3150 h compared to bare Zn (182 h) at 1.0 mAh cm-2-1.0 mAh cm-2, and excellent reversibility with an average Coulombic efficiency of 99.04% under a large plating capacity for 800 cycles. Moreover, the PVA/SFs@Zn||PANI/CC full cells maintain over 20 000 cycles with over 80% capacity retention under harsh conditions at 5 and 10 A g-1. This SF-modified protective layer for Zn anode suggests a promising strategy for reliable and high-performance ZIBs.

Activating the Intrinsic Zincophilicity of PAM Hydrogel to Stabilize the Metal-Electrolyte Dynamic Interface for Stable and Long-Life Zinc Metal Batteries.

As a potential material to solve rampant dendrites and hydrogen evolution reaction (HER) problem of aqueous zinc metal batteries (AZMB), hydrogel electrolytes usually require additional additives or multi-molecular network strategies to solve existing problems of ionic conductivity, mechanical properties and interface stability. However, the intrinsic zincophilic properties of the gel itself are widely neglected leading to the addition of additional molecules and the complexity of the preparation process. In this work, we innovatively utilize the characteristics of acrylamide's high zincophilic group density, activating the intrinsic zincophilic properties of PAM gel through a simple concentration control strategy which reconstructs a novel zinc-electrolyte interface different from conventional PAM electrolyte. The activated novel gel electrolyte with intrinsic zincophilic properties has high ionic conductivity and effectively suppresses water activity, thereby inhibiting HER corrosion. Meanwhile, it induces uniform deposition of (002) crystal planes, leading to excellent deposition kinetics and long cycle life, thereby ensuring high interfacial stability. Compared with conventional PAM gel electrolytes, the activated zincophilic group-rich hydrogel maintained excellent cycling stability (1 mA/cm2, 1 mAh/cm2) over 2250 hours; The Zn//MnO2 coin cell using novel zincophilic group -rich hydrogel still retains a high specific capacity of more than 170mAh/g at 0.5 A/g after 1000 cycles.

Constructing Highly Stable Zinc Metal Anodes via Induced Zn(002) Growth.

The nonuniform electric field at the surface of a zinc (Zn) anode, coupled with water-induced parasitic reactions, exacerbates the growth of Zn dendrites, presenting a significant impediment to large-scale energy storage in aqueous Zn-ion batteries. One of the most convenient strategies for mitigating dendrite-related issues involves controlling crystal growth through electrolyte additives. Herein, we present thiamine hydrochloride (THC) as an electrolyte additive capable of effectively stabilizing the preferential deposition of the Zn(002) plane. First-principles calculations reveal that THC tends to adsorb on Zn(100) and Zn(101) planes and is capable of inducing the deposition of Zn ion onto the (002) plane and the preferential growth of the (002) plane, resulting in a flat and compact deposition layer. A THC additive not only effectively suppresses dendrite growth but also prevents the generation of side reactions and hydrogen evolution reaction. Consequently, the Zn||Zn symmetric battery exhibits long-term cycling stability of over 3000 h at 1 mA cm-2/1 mAh cm-2 and 1000 h at 10 mA cm-2/10 mAh cm-2. Furthermore, the NH4V4O10||Zn full battery also displays excellent cycling stability and a high reversible capacity of 210 mAh g-1 after 1000 cycles at 1 A g-1, highlighting a significant potential for practical applications.

Influence of Dy3+ ions on spectroscopic studies of thermally stable telluro zinc phosphate glasses for white light emitting devices

A transparent series of telluro zinc phosphate glasses with varying Dy3+ ion concentrations (BTZPDy) were synthesized using a melt-quenching procedure. The non-crystalline/amorphous form of the BTZPDy glass matrices has been demonstrated via an X-ray diffraction (XRD) profile. As a way of recognizing the proficient usage of the obtained BTZPDy glass matrices in the white light emitting devices, the spectroscopic characteristics such as optical absorption, photoluminescence excitation (PLE) and emission, as well as temperature-dependent photoluminescence (TDPL) were conducted and investigated in detail. The absorption spectrum was determined in the n-UV to NIR range for the as-prepared BTZPDy1.0 glass sample and the optical energy band gap has been assessed via utilizing Tauc’s plot. In the visible range, photoluminescence spectra demonstrate three distinct emission peaks under different n-UV excitations, among which an intense emission peak around 575 nm is related to the 4F9/2 → 6H13/2 transition in the prepared BTZPDy glasses. The color coordinates (x, y) for the prepared BTZPDy1.0 glass were situated in the white light zone of the CIE graph and adjacent to the standard white light region (0.33, 0.33). Furthermore, TDPL spectral studies suggest the excellent thermal stability of BTZPDy glass samples alongside a high value of activation energy. In view of the above results, as-prepared BTZPDy glasses can be utilized for the fabrication of thermally stable white light emitting devices.

Ultrafast laser one-step construction of 3D micro-/nanostructures achieving high-performance zinc metal anodes

Aqueous zinc-ion batteries provide a most promising alternative to the existing lithium-ion batteries due to their high theoretical capacity, intrinsic safety, and low cost. However, commercializing aqueous zinc-ion batteries suffer from dendritic growth and side reactions on the surface of metallic zinc, resulting in poor reversibility. To overcome this critical challenge, here, we report a one-step ultrafast laser processing method for fabricating three-dimensional micro-/nanostructures on zinc anodes to optimize zinc nucleation and deposition processes. It is demonstrated that the three-dimensional micro-/nanostructure with increased specific surface area significantly reduces nucleation overpotential, as well as preferentially absorbs zinc ions to prevent dendritic protuberances and corrosion. As a result, the presence of three-dimensional micro-/nanostructures on the zinc metal delivers stable zinc plating/stripping beyond 2500 h (2 mA cm-2/1 mAh cm-2) in symmetric cells, a high Coulombic efficiency (99.71%) in half cells, and moreover an improved capacity retention (71.8%) is also observed in full cells. Equally intriguingly, the pouch cell with three-dimensional micro-/nanostructures can operate across various bending states without severely compromising performance. This work provides an effective strategy to construct ultrafine and high-precision three-dimensional micro-/nanostructures achieving high-performance zinc metal anodes and is expected to be of immediate benefit to other metal-based electrodes.

In-situ growth of hydrophobic zinc succinate interphase with high ionic conductivity toward stable zinc anodes

Aqueous zinc-ion batteries (ZIBs) are a promising solution for energy storage due to their affordability, high performance, environmental friendliness, and excellent safety features. However, zinc metal anodes are prone to capacity degradation and short circuits due to side reactions and dendrite growth during cycling. To address this issue, a dual-function artificial solid electrolyte interphase (SEI) made of zinc succinate complex (ZnSA) is in-situ constructed on zinc anodes by a simple and cost-effective soaking approach. This interphase is hydrophobic and highly ionic conductive (4.5 mS cm−1). It has a low electronic conductivity (1.6 mS cm−1) and a large Zn2+ transfer number (0.63). The hydrophobic SEI progressively represses water-induced side reactions, lowers zinc nucleation overpotential, accelerates zinc ion diffusion, and regulates homogeneous zinc deposition. As a result, the ZnSA@Zn symmetric cell achieves an impressive lifespan of 4450 h at 1 mA cm−2 for 0.5 mAh cm−2, which is significantly better than the bare zinc cell and superior to many recently reported zinc anodes. Furthermore, the V2O5//ZnSA@Zn batteries exhibit outstanding rate performance and remarkable long-term operation stability for 2000 cycles at 1 A/g. This innovative and cost-effective strategy opens up new possibilities for developing high-performance aqueous zinc-ion batteries.

The zinc finger motif in the mitochondrial large ribosomal subunit protein bL36m is essential for optimal yeast mitoribosome assembly and function

Ribosomes across species contain subsets of zinc finger proteins that play structural roles by binding to rRNA. While the majority of these zinc fingers belong to the C2-C2 type, the large subunit protein L36 in bacteria and mitochondria exhibits an atypical C2-CH motif. To comprehend the contribution of each coordinating residue in S. cerevisiae bL36m to mitoribosome assembly and function, we engineered and characterized strains carrying single and double mutations in the zinc coordinating residues. Our findings reveal that although all four residues markedly influence protein stability, C to A mutations in C66 and/or C69 have a more pronounced effect compared to those at C82 and H88. Importantly, protein stability directly correlates with the assembly and function of the mitoribosome and the growth rate of yeast in respiratory conditions. Mass spectrometry analysis of large subunit particles indicates that strains deleted for bL36m or expressing mutant variants have defective assembly of the L7/L12 stalk base, limiting their functional competence. Furthermore, we employed a synthetic bL36m protein collection, including both wild-type and mutant proteins, to elucidate their ability to bind zinc. Our data indicate that mutations in C82 and, particularly, H88 allow for some zinc binding albeit inefficient or unstable, explaining the residual accumulation and activity in mitochondria of bL36m variants carrying mutations in these residues. In conclusion, stable zinc binding by bL36m is essential for optimal mitoribosome assembly and function. MS data are available via ProteomeXchange with identifierPXD046465.

Phase Inversion‐Induced Porous Polymer Coating for High Rate and Stable Zinc Anode

AbstractPolymer coatings are emerged as promising candidates for zinc anode artificial solid electrolyte interphase (ASEI) owing to their barrier effect and zincophilicity. However, the poor ionic conductivity of conventional polymer coatings limits their application. Herein, inspired by epidermis function, a porous poly(methylmethacrylate) (PMMA) coating is fabricated to stabilize Zn anode via a novel phase inversion method. The modified Zn anode delivers a remarkable lifespan of over 4000 h at 1 mA cm−2, 1 mAh cm−2, and 120 h at 20 mA cm−2, 20 mAh cm−2 in symmetrical cells. Moreover, porous PMMA‐Zn||NVO full cell also exhibits an excellent cycling stability over 500 cycles at 1 A g−1 as well as an ultralong lifespan exceeding 5000 cycles at 5 A g−1. The excellent cycling stability and rate performance are mainly attributed to the avoided side reactions by the coating protection, as well as the enhanced diffusion and reaction kinetics derived from the good zincophilicity and porous structure of porous PMMA. The facile and universal method for fabricating porous polymer ASEI provides a new insight for the application of conventional polymer materials in Zn anode protection.

Ternary Zn3V3O8 superstructure and synergistic modification of separator promote high performance and stable zinc ion battery

Aqueous zinc-ion batteries have attracted much attention from researchers owing to their safety and eminent energy density. However, the exploration of an appropriate cathode with high reversible capacity is still a huge challenge. In this manuscript, the ternary Zn3V3O8 superstructure with an energy density of 317 Wh kg−1 was successfully prepared with a micro-nano ternary hierarchical structure and the incorporation doping of nitrogen and carbon (ZVO@CN). Thanks to the multilevel morphology and high conductivity of carbon and nitrogen, the novel ZVO@CN cathode delivers the eminent reversible capacity of 192 mAh/g at 5 A/g after 2200 cycles for aqueous zinc ion battery. Importantly, the ex-situ XRD and XPS were adopted to explore the energy storage kinetics. Consequently, the pristine material is been transformed to Zn3(OH)2V2O7·2H2O in the initial charging at 1.3 V, and this phase transition is nonreversible. After the second cycle, the intercalation/extraction of Zn2+ in Zn3(OH)2V2O7·2H2O supplies the reversible capacity. Besides, to solve the rapid capacity delay caused by dendrite growth at low current density on the Zn anodes, the C3N4 coating Zn is prepared to modify the separator (Zn@C3N4@GF). It has effectively relieved the negative effect of Zn dendrite with highly improved stability. When the ZVO@CN and Zn@C3N4@GF were used as cathode and separator, the batteries exhibited a dominant discharge capacity of 235 mAh/g at 0.1 A/g after 380 cycles, only reducing the 50 mAh/g compared to the initial capacity. This means it only decreases the discharge capacity of 0.13 mA g−1 per cycle.

Endogenous Organic–Inorganic Hybrid Interface for Reversible Zn Electrochemistry

AbstractDespite rechargeable aqueous Zn‐ion batteries (AZIBs) exhibit advantages such as high safety, high specific energy, and low cost, etc, the implementation of Zn anodes is still hampered by insufficient cyclability and grievous side reactions. To improve the cycling stability of the zinc anode, a stable zinc anode/electrolyte interface is needed to suppress dendrite formation and side reactions. Herein, a self‐regulating endogenous organic–inorganic hybrid interface layer (EHI) in situ on the surface of the Zn anode by regulating solvent molecules is constructed. The EHI consists of an organic outer layer containing N─H and ─CH3 and an inorganic inner layer containing ZnO and ZnCO3, which effectively inhibits hydrogen evolution and dendrite growth. Consequently, AZIBs with the EHI achieve a lifespan exceeding 5500 h in 3 mA cm−2, and stripping/plating on copper foils for 600 cycles with an average coulomb efficiency (CE) of 99.47%. This study provides a feasible idea for realizing stable and reversible zinc‐ion batteries.

Achieving an ion-homogenizing and corrosion-resisting interface through nitro-coordination chemistry for stable zinc metal anodes

Suppression of uncontrollable dendrite growth and water-induced side reactions of Zn metal anodes is crucial for achieving long-lasting cycling stability and facilitating the practical implementations of aqueous Zn-metal batteries. To address these challenges, we report in this study a functional nitro-cellulose interfacial layer (NCIL) on the surface of Zn anodes enlightened by a nitro-coordination chemistry strategy. The NCIL exhibits strong zincophilicity and superior coordination capability with Zn2+ due to the highly electronegative and highly nucleophilic nature of the nitro functional group. This characteristic facilitates a rapid Zn-ion desolvation process and homogeneous Zn plating, effectively preventing H2 evolution and dendrite formation. Additionally, the negatively charged surface of NCIL acts as a shield, repelling SO42− anions and inhibiting corrosive reactions on the Zn surface. Remarkably, reversible and stable Zn plating/stripping is achieved for over 5100 h at a current density of 1 mA cm−2, which is nearly 30 times longer than that of bare Zn anodes. Furthermore, the Zn//V2O5 full cells with the functional interface layer deliver a high-capacity retention of 80.3% for over 10,000 cycles at 5 A g−1. This research offers valuable insights for the rational development of advanced protective interface layers in order to achieve ultra-long-life Zn metal batteries.

The Construction of Anion‐Induced Solvation Structures in Low‐concentration Electrolyte for Stable Zinc Anodes

AbstractAqueous zinc‐ion batteries (ZIBs) are promising large‐scale energy storage devices because of their low cost and high safety. However, owing to the high activity of H2O molecules in electrolytes, hydrogen evolution reaction and side reactions usually take place on Zn anodes. Herein, additive‐free PCA−Zn electrolyte with capacity of suppressing the activity of free and solvated H2O molecules was designed by selecting the cationophilic and solventophilic anions. In such electrolyte, contact ion‐pairs and solvent‐shared ion‐pairs were achieved even at low concentration, where PCA− anions coordinate with Zn2+ and bond with solvated H2O molecules. Simultaneously, PCA− anions also induce the construction of H‐bonds between free H2O molecules and them. Therefore, the activity of free and solvated H2O molecules is effectively restrained. Furthermore, since PCA− anions possess a strong affinity with metal Zn, they can also adsorb on Zn anode surface to protect Zn anode from the direct contact of H2O molecules, inhibiting the occurrence of water‐triggered side reactions. As a result, plating/stripping behavior of Zn anodes is highly reversible and the coulombic efficiency can reach to 99.43 % in PCA−Zn electrolyte. To illustrate the feasibility of PCA−Zn electrolyte, the Zn||PANI full batteries were assembled based on PCA−Zn electrolyte and exhibited enhanced cycling performance.

The Construction of Anion-Induced Solvation Structures in Low-concentration Electrolyte for Stable Zinc Anodes.

Aqueous zinc-ion batteries (ZIBs) are promising large-scale energy storage devices because of their low cost and high safety. However, owing to the high activity of H2O molecules in electrolytes, hydrogen evolution reaction and side reactions usually take place on Zn anodes. Herein, additive-free PCA-Zn electrolyte with capacity of suppressing the activity of free and solvated H2O molecules was designed by selecting the cationophilic and solventophilic anions. In such electrolyte, contact ion-pairs and solvent-shared ion-pairs were achieved even at low concentration, where PCA- anions coordinate with Zn2+ and bond with solvated H2O molecules. Simultaneously, PCA- anions also induce the construction of H-bonds between free H2O molecules and them. Therefore, the activity of free and solvated H2O molecules is effectively restrained. Furthermore, since PCA- anions possess a strong affinity with metal Zn, they can also adsorb on Zn anode surface to protect Zn anode from the direct contact of H2O molecules, inhibiting the occurrence of water-triggered side reactions. As a result, plating/stripping behavior of Zn anodes is highly reversible and the coulombic efficiency can reach to 99.43 % in PCA-Zn electrolyte. To illustrate the feasibility of PCA-Zn electrolyte, the Zn||PANI full batteries were assembled based on PCA-Zn electrolyte and exhibited enhanced cycling performance.