Revitalizing Dead Zinc with Ferrocene/Ferrocenium Redox Chemistry for Deep-Cycle Zinc Metal Batteries.

Aqueous zinc (Zn) batteries are highly desirable for sustainable and large-scale electrochemical energy storage technologies. However, the ceaseless dendrite growth and the derived dead Zn are principally responsible for the capacity decay and insufficient lifespan. Here, we propose a dissolved oxygen-initiated revitalization strategy to reactivate dead Zn via ferrocene redox chemistry, which can be realized by incorporating a trace amount of poly(ethylene glycol) as a solubilizer to improve the solubility of water-insoluble ferrocene derivatives. Ferrocene scaffold can be spontaneously oxidized to ferricenium cations by dissolved oxygen, which eradicates the dissolved oxygen-involved Zn corrosion and insulating by-product generation. Subsequently, the generated ferricenium cations as the scavenger can rejuvenate electrically isolated dead Zn into electroactive Zn2+ ions to compensate the zinc loss. Through this design, the symmetric cell exhibited improved cycle life of 3700 h at 10 mA cm-2, and 220 h under a high depth of discharge of 80%. Importantly, the Zn||NaV3O8·1.5H2O full cells demonstrated the impressive cycling stability over 1000 cycles at a low N/P ratio of 3.0. This work presents an innovative solution for the revitalization of dead Zn to extend the lifespan of deep-cycling metal batteries.

Integrated Interfacial Modulation Strategy: Trace Sodium Hydroxyethyl Sulfonate Additive for Extended-Life Zn Anode Based on Anion Adsorption and Electrostatic Shield.

Aqueous zinc-ion batteries (AZIBs) are poised to play a pivotal part in meeting the growing demands for energy storage and powering portable electronics for their superior security, affordability, and environmentally friendly characteristics. However, the detrimental side reactions occurring at the zinc anode and the dendrite caused by uneven zinc plating/stripping have greatly compromised the cycling life of AZIBs, thereby impeding their practical prospects. In this study, the interfacial comodulation strategy was employed by combining the "electrostatic shielding" effect of cations with the characteristic adsorption of anions. Two molar ZnSO4 served as the matrix, and sodium hydroxyethyl sulfonate (SHES) was selected as a low-cost, nontoxic additive. Experimental results confirm that SHES and zinc anode exhibit robust interactions that lead to the formation of an electrostatic shield and a dynamic adsorption layer at the interface, thereby suppressing hydrogen evolution and corrosion. The combined "electrostatic shielding" effect of sodium ions and the robust characteristic adsorption of hydroxyethyl sulfonate anions serve to guide the directed three-dimensional (3D) diffusion of Zn2+, facilitating rapid, stable, and uniform deposition of zinc. Due to these effects, incorporating 0.2 M SHES as an additive extends the cycle life beyond 3600 h and enables a highly reversible process of deposition and stripping in symmetric cells. Additionally, the Zn-Cu half-cell exhibits reliable cycling for over 1400 cycles, achieving an average Coulombic efficiency of 99.6%. Moreover, the introduction of this additive substantially enhances the performance of Zn-MnO2 and Zn-NH4V4O10 full cells. This study demonstrates the practical feasibility of achieving anodes with high reversibility in AZIBs through the implementation of a strategy that involves anion adsorption at the interface, which holds paramount significance for the practical application of AZIBs.

Multifunctional Self-Assembled Bio-Interfacial Layers for High-Performance Zinc Metal Anodes.

Rechargeable aqueous zinc-ion (Zn-ion) batteries are widely regarded as important candidates for next-generation energy storage systems for low-cost renewable energy storage. However, the development of Zn-ion batteries is currently facing significant challenges due to uncontrollable Zn dendrite growth and severe parasitic reactions on Zn metal anodes. Herein, we report an effective strategy to improve the performance of aqueous Zn-ion batteries by leveraging the self-assembly of bovine serum albumin (BSA) into a bilayer configuration on Zn metal anodes. BSA's hydrophilic and hydrophobic fragments form unique and intelligent ion channels, which regulate the migration of Zn ions and facilitate their desolvation process, significantly diminishing parasitic reactions on Zn anodes and leading to a uniform Zn deposition along the Zn (002) plane. Notably, the Zn||Zn symmetric cell with BSA as the electrolyte additive demonstrated a stable cycling performance for up to 2400 hours at a high current density of 10 mA cm-2. This work demonstrates the pivotal role of self-assembled protein bilayer structures in improving the durability of Zn anodes in aqueous Zn-ion batteries.

Bifunctional Catalysts for CO2 Reduction and O2 Evolution: A Pivotal for Aqueous Rechargeable Zn-CO2 Batteries.

The quest for the advancement of green energy storage technologies and reduction of carbon footprint is determinedly rising toward carbon neutrality. Aqueous rechargeable Zn-CO2 batteries (ARZCBs) hold the great potential to encounter both the targets simultaneously, i.e., green energy storage and CO2 conversion to value-added chemicals/fuels. The major descriptor of ARZCBs efficiency is allied with the reactions occurring at cathode during discharging (CO2 reduction) and charging (O2 evolution) which own different fundamental mechanisms and hence mandate the employment of two different catalysts. This presents an overall complex and expensive battery system which requires a concrete solution, while the development and application of a bifunctional cathode catalyst toward both reactions could reduce the complexity and cost and thus can be a pivotal for ARZCBs. However, despite the increasing research interest and ongoing research, a systematic evaluation of bifunctional catalysts is rarely reported. In this review, the need of bifunctional cathode catalysts for ARZCBs and associated challenges with strategies have been critically assessed. A detailed progress examination and understanding toward designing of bifunctional catalyst for ARZCBs have been provided. This review will enlighten the future research approaching boosted performance of ARZCBs through the development of efficient bifunctional cathode catalysts.

Achieving Planar Zn Electroplating in Aqueous Zinc Batteries with Cathode-Compatible Current Densities by Cycling under Pressure.

The value of aqueous zinc-ion rechargeable batteries is held back by the degradation of the Zn metal anode with repeated cycling. While raising the operating current density is shown to alleviate this anode degradation, such high cycling rates are not compatible with full cells, as they cause Zn-host cathodes to undergo capacity decay. A simple approach that improves anode performance while using more modest cathode-compatible current densities is required. This work reports reversible planar Zn deposition under cathode-compatible current densities can instead be achieved by applying external pressure to the cell. Employing multiscale characterization, this work illustrates how cycling under pressure results in denser and more uniform Zn deposition, analogous to that achieved under high cycling rates, even at low areal current densities of 1 to 10 mA cm-2. Microstructural mechanical measurements reveal that Zn structures plated under lower current densities are particularly susceptible to pressure-induced compression. The ability to achieve planar Zn plating at cathode-compatible current densities holds significant promise for enabling high-capacity Zn-ion battery full cells.

Regulating Desolvation Activation Energy and Zn Deposition via a CTAB-Intercalated Mg-Al-Layered Double-Hydroxide Protective Layer for Durable Zn Metal Anodes.

While aqueous Zn-ion batteries (AZIBs) are widely considered as a promising energy storage system due to their merits of low cost, high specific capacity, and safety, the practical implementation has been hindered by the Zn dendrite growth and undesirable parasitic reactions. To address these issues, a unique hydrophobic-ion-conducting cetyltrimethylammonium bromide-intercalated Mg-Al-layered double-hydroxide protective layer was constructed on the Zn anode (OMALDH-Zn) to modulate the nucleation behavior and desolvation process. The hydrophobic cetyl group long chain can inhibit the hydrogen evolution reaction and Zn corrosion by repelling water molecules from the anode surface and reducing the desolvation activation energy. Meanwhile, the Mg-Al LDH with abundant zincophilic active sites can modulate the Zn2+ ion flux, enabling the dendrite-free Zn deposition. Benefiting from this interfacial synergy, a long cycle life (>2300 h) with low and stable overpotential (<18 mV at 1 mA cm-2) and excellent Coulombic efficiency (99.4%) for symmetrical and asymmetrical batteries were achieved. More impressively, excellent rate performance and long cyclic stability have been realized by OMALDH-Zn//MnO2 batteries in both coin-type and pouch-type devices. This low-cost, simple, and high-efficiency coordinated modulation method provides a reliable strategy for the practical application of AZIBs.

Constructing 3D Zincophilic Skeleton in Nitrogen-Doped Carbon Hybrid Fibers for Dendrite-Free Zn Anodes.

The Zn dendrite growth and side reactions are two major issues for the practical use of Zn metal anodes (ZMAs). Herein, an N-doped carbon-based hybrid fiber with the 3D porous skeleton and the zincophilic Cu nanoparticles (denoted as Cu@HLCF) is developed for stable ZMAs. The zincophilic Cu particles in the skeleton work as the active sites to facilitate uniform Zn nucleation. Meanwhile, the abundant pores in the framework of the hybrid fibers provide a large space to relieve the structural stress and suppress the dendrite growth. Moreover, the good mechanical characteristics of the hybrid fiber ensure its high potential applications for flexible electronics. Theoretical analysis results disclose the strong interaction between Zn and Cu sites, and experimental results demonstrate the low voltage hysteresis, high reversibility, and dendrite-free behavior of the Cu@HLCF host for Zn plating/stripping. Moreover, the solid-state Zn-ion battery (ZIB) assembled with a Cu@HLCF/Zn anode shows the prominent flexibility, impressively reliability, and outstanding cycling capability. Therefore, this work not only provides a novel design for the efficient and stable Zn metal anode but also promotes the development of flexible power sources for flexible electronics.

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.

Constructing Stable Zinc-Metal Anodes by Synergizing Hydrophobic Host with Zincophilic Interface for Aqueous Zinc Ions Batteries.

Aqueous zinc (Zn) ions battery is promising for future large-scale applications of energy storage due to the abundant reserves, high capacity of metallic Zn. However, dendritic growth, severe side reactions have limited the development of Zn-metal anodes. A single skeleton structure or interface protection is difficult to simultaneously mitigate these issues. Here, a novel composite design based on the synergistic interaction between the hydrophobic host, the zincophilic interface is reported. On the one hand, the 3D substrate reduces the local current density, inhibits dendritic growth. On the other hand, the protective interface homogenizes the nucleation due to the formation of the ZnAu3 alloy layer. More importantly, the collaborative construction of the hydrophobicity, zincophilicity for the electrode alleviates the aggravated hydrogen evolution reaction (only 2.5 mmol h-1 ), simultaneously enables a low nucleation overpotential (31.7 mV) during cycling. Consequently, a high Coulombic efficiency of ≈98.25% after 300 cycles is harvested for the composite electrode. The pouch cells assembled by this anode, LiMn2 O4 cathode maintain 82 mAh g-1 capacity retention after 140 cycles. This research shows an innovative Zn-based structural design for aqueous Zn-ion batteries.

Concentration-Driven Interfacial Amorphization toward Highly Stable and High-Rate Zn Metal Batteries.

The interfacial structure holds great promise in suppressing dendrite growth and parasitic reactions of zinc metal in aqueous media. Current advancements prioritize novel component fabrication, yet the local crystal structure significantly impacts the interfacial properties. In addition, there is still a critical need for scalable synthesis methods for expediting the commercialization of aqueous zinc metal batteries (AZMBs). Herein, we propose a scalable concentration-controlled method for realizing crystalline to amorphous transformation of the Zn metal interface with exceptional scalability (>1 m2) and processing consistency (>30 trials). Theoretical and experimental analyses highlight the advantages of amorphous ZnO, which exhibits moderate adsorption energy, strong desolvation ability, and hydrophilicity. Employing the amorphous ZnO-coated zinc metal anode (AZO-Zn) significantly enhances the cycling performance, impressively maintaining 1000 cycles at 100 mA cm-2. The prototype AZO-Zn||MnO2@CNT pouch cell demonstrates a capacity of 15.7 mAh and maintains 91% of its highest capacity over 100 cycles, presenting promising avenues for the future commercialization of AZMBs.

Converting Commercial Zn Foils into Single (002)-Textured Zn with Millimeter-Sized Grains for Highly Reversible Aqueous Zinc Batteries.

Rechargeable aqueous zinc batteries are promising but hindered by unfavorable dendrite growth and side reactions on zinc anodes. In this study, we demonstrate a fast melting-solidification approach for effectively converting commercial Zn foils into single (002)-textured Zn featuring millimeter-sized grains. The melting process eliminates initial texture, residual stress, and grain size variations in diverse commercial Zn foils, guaranteeing the uniformity of commercial Zn foils into single (002)-textured Zn. The single (002)-texture ensures large-scale epitaxial and dense Zn deposition, while the reduction in grain boundaries significantly minimizes intergranular reactions. These features enable large grain single (002)-textured Zn shows planar and dense Zn deposition under harsh conditions (100 mA cm-2, 100 mAh cm-2), impressive reversibility in Zn||Zn symmetric cell (3280 h under 1 mA cm-2, 830 h under 10 mAh cm-2), and long cycling stability over 180 h with a high depth of discharge value of 75 %. This study successfully addresses the issue of uncontrollable texture formation in Zn foils following routine annealing treatments with temperatures below the Zn melting point. The findings of this study establish a highly efficient strategy for fabricating highly reversible single (002)-textured Zn anodes.

Atomic Zincophilic Sites Regulating Microspace Electric Fields for Dendrite-Free Zinc Anode.

Aqueous Zn metal batteries are promising candidates for large-scale energy storage due to their intrinsic advantages. However, Zn tends to deposit irregularly and forms dendrites driven by the uneven space electric field distribution near the Zn-electrolyte interphase. Herein it is demonstrated that trace addition of Co single atom anchored carbon (denoted as CoSA/C) in the electrolyte regulates the microspace electric field at the Zn-electrolyte interphase and unifies Zn deposition. Through preferential adsorption of CoSA/C on the Zn surface, the atomically dispersed Co-N3 with strong charge polarization effect can redistribute the local space electric field and regulate ion flux. Moreover, the dynamic adsorption/desorption of CoSA/C upon plating/stripping offers sustainable long-term regulation. Therefore, Zn||Zn symmetric cells with CoSA/C electrolyte additive deliver stable cycling up to 1600 h (corresponding to a cumulative plated capacity of 8 Ah cm-2 ) at a high current density of 10 mA cm-2 , demonstrating the sustainable feature of microspace electric field regulation at high current density and capacity.

Inorganic Hybrid Interfacial Layer for a Stable Zinc Metal Anode.

In aqueous zinc-ion batteries (AZIBs), the zinc metal anode faces serious problems such as dendrite growth, interface corrosion, and byproduct accumulation, which hinder the commercialization process of AZIBs. Herein, an inorganic hybrid interfacial layer ZnF2/ZnSe (ZnFS) including the insulating interfacial phase (ZnF2) and conductive interfacial phase (ZnSe) has been manufactured. ZnF2 provides excellent corrosion resistance, inhibiting the corrosion and passivation of the zinc metal anode to enhance interfacial stability. The conductive ZnSe can reduce the interfacial resistance and induce the rapid migration of Zn2+, leading to the uniform deposition of Zn to inhibit the dendrite growth. Consequently, the Zn/ZnFS//Zn/ZnFS symmetrical batteries can run stably for more than 2200 h at 1 mA cm-2/1 mAh cm-2 and over 700 h at 5 mA cm-2/5 mAh cm-2. At the same time, the average Coulombic efficiency of the Zn/ZnFS//Ti half batteries reaches 98.3% after 600 cycles (1 mA cm-2/1 h), indicating that the reversibility of zinc was greatly improved. The full batteries based on the Zn/ZnFS anode and (NH4)2V10O25·8H2O cathode perform a high capacity ratio of 73.4% after 620 cycles at 1 A g-1. The concept of hybrid interface layer design can provide inspiration for the modification of metal anode.

Building Ion-Conductive Supramolecular Elastomeric Protective Layer via Dynamic Hard Domain Design for Stable Zinc Metal Anodes.

The instability of zinc metal anode caused by zinc dendrite growth and severe parasitic reactions has significantly restricted the extensive application of rechargeable aqueous zinc-ion batteries (RAZBs). Herein, based on the strategy of dynamic hard domains, we develop an ion-conductive supramolecular elastomer consisting of Zn salts and the polyurethane-urea-polypropylene glycol polymer skeleton. This elastomer combines high mechanical strength, high ionic conductivity, decent hydrophobicity, and high adhesion to stabilize the electrode-electrolyte interface. In the elastomer system, this elastomer can dynamically adapt to the volume changes of Zn anodes during repeated zinc plating/stripping processes through the reversible dissociation/reassociation of hierarchical hydrogen bonds (H-bonds) formed by the polar groups of urea and urethane moieties. Meanwhile, the coordination of Zn2+ with soft polypropylene glycol (PPG) segments contributes to fast ion transport. This hydrophobic elastomer can also effectively inhibit water-induced corrosion by shielding the active Zn metal from the aqueous electrolyte. Based on the above synergies, the surface-modified anode shows excellent cycling stability above 550 h at a high current density of 5 mA cm-2 and a capacity of 2.5 mAh cm-2. Moreover, the assembled Zn//MnO2 full cell also displayed an enhanced electrochemical performance. This work provides inspiration for the design of solid electrolyte interphase (SEI) layers in aqueous battery chemistry to accelerate the application of RAZBs.

Ion Diffusion-Directed Assembly of an Artificial Electronic-Ionic Conductor Layer with Zn-Ion Selective Channels for Highly Reversible Zinc Anodes.

Although aqueous zinc-ion batteries have attracted much attention due to their high safety, low cost, and relatively high energy density, their practical applications are severely limited by the uncontrollable dendrite growth and side reactions at the zinc anode. Herein, we design an electronic-ionic conductor artificial layer with Zn-ion selective channels on the Zn surface to regulate the Zn plating/stripping behavior through a one-step ion diffusion-directed assembly strategy using the commercially available conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). Significantly, the functional PEDOT:PSS-Zn2+ (PPZ) layer with abundant selective Zn-ion channels works as both an electron regulator and an ion regulator that could not only simultaneously uniformize the electrical and Zn2+ concentration field on the Zn surface and accelerate the Zn2+ transport kinetics but also block the access of SO42- and H2O. With such a synergy effect, the PEDOT:PSS-Zn2+-modified Zn anode (2PPZ@Zn) achieves a long lifespan of 2400 h of the symmetrical cell at a current density of 3 mA cm-2 (1 mA h cm-2). Additionally, a long-term lifespan of 500 h is harvested even at a high current of 5 mA cm-2 with a high capacity of 3 mA h cm-2. Furthermore, combined with a manganese dioxide cathode, a full cell similarly provides a cycling stability of over 1500 cycles with 75% capacity retention at a high rate of 10 C (1 C = 308 mA h g-1).

Regulated Ion/Electron-Conducting Interphase Enables Stable Zinc-Metal Anodes for Aqueous Zinc-Ions Batteries.

Metallic Zinc (Zn) is considered as a remarkably promising anode for aqueous Zn-ion batteries due to its high volumetric capacity and low redox potential. Unfortunately, dendritic growth and severe side reactions destabilizes the electrode/electrolyte interface, and ultimately reduce the electrochemical performance. Here, an artificial protective layer (APL) with a regulated ion and electron-conducting interphase is constructed on the Zn-metal anode to provide excellent interfacial stability in high-rate cycling. The superior ionic and moderate electronic conductivity of the APL derives from the co-embedding of MXene and Zn(CF3 SO3 )2 salts into the polyvinyl alcohol hydrogel, which enables a synergistic effect of local current density reduction during plating and ion transport acceleration during stripping for Zn anode. Furthermore, the high Young's modulus of the protective layer and dendrite-free deposition morphology during cycling suppresses hydrogen evolution reactions (2.5 mmol h-1 cm-2 ) and passivation. As a result, in symmetrical cell tests, the modified battery presents a stable life of over 2000 cycles at ultra-high current density of 20 mA cm-2 . This research presents a new insight into the formation and regulation of stable electrode-electrolyte interface for the Zn-metal anode.

Robust and Wide Temperature-Range Zinc Metal Batteries with Unique Electrolyte and Substrate Design.

Rechargeable zinc metal batteries are promising for large-scale energy storage. However, their practical application is limited by harsh issues such as uncontrollable dendrite growth, low Coulombic efficiency, and poor temperature tolerance. Herein, a unique design strategy using γ-valerolactone-based electrolyte and nanocarbon-coated aluminum substrate was reported to solve the above problems. The electrolyte with extremely low freezing point and high thermal stability enables the symmetric cells with long cycle life over a wide temperature range (-50 °C to 80 °C) due to its ability to regulate zinc nucleation and preferential epitaxial growth. Besides, the nanocarbon-coated aluminum substrate can also promote a higher Coulombic efficiency over a wide temperature range in contrast to the low Coulombic efficiency of copper substrates with significant irreversible alloying reactions because this unique substrate with excellent chemical stabilization can homogenize the interfacial electron/ion distribution. The optimized zinc metal capacitors can operate stably under various temperature conditions (2000 cycles at 30 °C with 66 % depth of discharge and 1200 cycles at 80 °C with 50 % depth of discharge). This unique electrolyte and substrate design strategy achieves a robust zinc metal battery over a wide temperature range.

Regulating the MXene-Zinc Interfacial Structure toward a Highly Revisable Metal Anode of Zinc-Air Batteries.

Rechargeable aqueous Zn-air batteries have been regarded as one of the most promising systems for flexible energy storage devices due to their high specific energy, safety, and cost effectiveness. However, Zn metal anodes exposed to strong alkaline electrolytes suffer from several issues such as corrosion, dissolution, and passivation, resulting in extremely poor cycle reversibility. Motivated by this challenge, we herein strategically design an MXene/Zn metal anode interfacial structure with single/few-layer Ti3C2Tx MXene as a protective layer. Such a design not only isolates the direct contact between Zn metal anodes and electrolytes but also inhibits zincate dissolution due to the ion screening function of Ti3C2Tx, potentially addressing the stubborn issues that Zn anodes faced with. As a result, the Ti3C2Tx-protected Zn metal anode exhibits superior cycle stability (stable for more than 400 cycles) to the bare Zn counterpart (20 cycles) at a high current density of 5.0 mA cm-2. When integrated into Zn-air coin cells, it has a high depth of discharge of 91% and operates stably for 140 cycles with small resistance. More interestingly, the excellent flexibility of the as-designed Ti3C2Tx-protected Zn metal anode endows the quasi-solid-state batteries with admirable voltage stability at different bending angles from 0 to 180°.

Quasi-Solid Electrolyte Interphase Boosting Charge and Mass Transfer for Dendrite-Free Zinc Battery.

The practical applications of zinc metal batteries are plagued by the dendritic propagation of its metal anodes due to the limited transfer rate of charge and mass at the electrode/electrolyte interphase. To enhance the reversibility of Zn metal, a quasi-solid interphase composed by defective metal-organic framework (MOF) nanoparticles (D-UiO-66) and two kinds of zinc salts electrolytes is fabricated on the Zn surface served as a zinc ions reservoir. Particularly, anions in the aqueous electrolytes could be spontaneously anchored onto the Lewis acidic sites in defective MOF channels. With the synergistic effect between the MOF channels and the anchored anions, Zn2+ transport is prompted significantly. Simultaneously, such quasi-solid interphase boost charge and mass transfer of Zn2+, leading to a high zinc transference number, good ionic conductivity, and high Zn2+ concentration near the anode, which mitigates Zn dendrite growth obviously. Encouragingly, unprecedented average coulombic efficiency of 99.8% is achieved in the Zn||Cu cell with the proposed quasi-solid interphase. The cycling performance of D-UiO-66@Zn||MnO2 (~ 92.9% capacity retention after 2000 cycles) and D-UiO-66@Zn||NH4V4O10 (~ 84.0% capacity retention after 800 cycles) prove the feasibility of the quasi-solid interphase.

Nanoscale Ultrafine Zinc Metal Anodes for High Stability Aqueous Zinc Ion Batteries.

Aqueous Zn batteries (AZBs) are a promising energy storage technology, due to their high theoretical capacity, low redox potential, and safety. However, dendrite growth and parasitic reactions occurring at the surface of metallic Zn result in severe instability. Here we report a new method to achieve ultrafine Zn nanograin anodes by using ethylene glycol monomethyl ether (EGME) molecules to manipulate zinc nucleation and growth processes. It is demonstrated that EGME complexes with Zn2+ to moderately increase the driving force for nucleation, as well as adsorbs on the Zn surface to prevent H-corrosion and dendritic protuberances by refining the grains. As a result, the nanoscale anode delivers high Coulombic efficiency (ca. 99.5%), long-term cycle life (over 366 days and 8800 cycles), and outstanding compatibility with state-of-the-art cathodes (ZnVO and AC) in full cells. This work offers a new route for interfacial engineering in aqueous metal-ion batteries, with significant implications for the commercial future of AZBs.