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Three dimensional (3D) framework structure is one of the most effective ways to achieve uniform zinc deposition and thus inhibit the Zn dendrites growth in working Zn metallic anode. A major challenge facing for the most commonly used 3D zincophilic hosts is that the zincophilic layer tends to peel off during repeatedly cycling, making it less stable. Herein, for the first time, a hetero-superlattice Zn/ZnLi (HS-Zn/ZnLi) anode containing periodic arrangements of metallic Zn phase and zincophilic ZnLi phase at the nanoscale, is well designed and fabricated via electrochemical lithiation method. Based on binding energy and stripping energy calculation, and the operando optical observation of plating/stripping behaviors, the zincophilic ZnLi sites with a strong Zn adsorption ability in the interior of the 3D ZnLi framework structure can effectively guide uniform Zn nucleation and dendrite-free zinc deposition, which significantly improves the cycling stability of the HS-Zn/ZnLi alloy (over 2800 h without a short-circuit at 2 mA cm -2 ). More importantly, this strategy can be extended to HS-Zn/ZnNa and HS-Zn/ZnK anodes that are similar to the HS-Zn/ZnLi microstructure, also displaying significantly enhanced cycling performances in AZIBs. This study can provide a novel strategy to develop the dendrite-free metal anodes with stable cycling performance., (© 2024 Wiley-VCH GmbH.)

To construct an efficient regulating layer for Zn anodes that can simultaneously address the issues of dendritic growth and side reactions is highly demanded for stable zinc metal batteries (ZMBs). Herein, we fabricate a hydrogen-bonded organic framework (HOF) enriched with zincophilic sites as a multifunctional layer to regulate Zn anodes with controlled spatial ion flux and stable interfacial chemistry (MA-BTA@Zn). The framework with abundant H-bonds helps capture H 2 O and remove the solvated shells on [Zn(H 2 O) 6 ] 2+ , leading to suppressed side reactions. The HOF layer also helps form electrolyte-philic surfaces and expose Zn (002) crystal planes which benefit for rapid conduction and uniform deposition of Zn 2+ , and weakened sides reactions. Additionally, the electrochemically active zincophilic sites (C=O, -NH 2 and triazine groups) favor the targeted guidance and penetration of Zn 2+ and provide advantageous sites for uniform Zn deposition. High Young's modulus of the HOF layer further contributes to a high interfacial flexibility and stability against Zn plating-associated stress. The MA-BTA@Zn symmetric cells thereby obtain a substantially extended battery life over 1000 h at 4 mA cm -2 . The MA-BTA@Zn||Cu half-cell demonstrates a highly reversible Zn stripping/plating process over 1500 cycles with impressive average Coulombic efficiency (CE) of 99.5 % at 10 mA cm -2 ., (© 2024 Wiley-VCH GmbH.)

Uncontrollable growth of Zn dendrites, irreversible dissolution of cathode material and solidification of aqueous electrolyte at low temperatures severely restrict the development of aqueous Zn-ion batteries. In this work, 2,2,2-trifluoroethanol (TFEA) with a volume fraction of 50% as a highly compatible polar-solvent is introduced to 1.3 M Zn(CF 3 SO 3 ) 2 aqueous electrolyte, achieving stable high-performance Zn-ion batteries. Massive theoretical calculations and characterization analysis demonstrate that TFEA weakens the tip effect of Zn anode and restrains the growth of Zn dendrites due to electrostatic adsorption and coordinate with H 2 O to disrupt the hydrogen bonding network in water. Furthermore, TFEA increases the wettability of the cathode and alleviates the dissolution of V 2 O 5 , thus improving the capacity of the full battery. Based on those positive effects of TFEA on Zn anode, V 2 O 5 cathode, and aqueous electrolyte, the Zn//Zn symmetric cell delivers a long cycle-life of 782 h at 5 mA cm -2 and 2 mA h cm -2 . The full battery still declares an initial capacity of 116.78 mA h g -1 , and persists 87.73% capacity in 2000 cycles at -25 °C. This work presents an effective strategy for fully compatible co-solvent to promote the stability of Zn anode, V 2 O 5 cathode and aqueous electrolyte for high-performance Zn-ion batteries., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

This work reports a novel 3D printed grid reservoir-integrated mesoporous carbon coordinated silicon oxycarbide hybrid composite (3DP-MPC-SiOC) to establish the zincophile interphase for controlling the dendrite formation. The customized 3D printed grid patterned structure inhibits Zn dendrite growth and achieves long-term stability with reduced voltage polarization due to homogeneous electric field distribution. The hybrid composite consisting of SiOC interpenetrated within carbon constructs a high zinc nucleation interphase, hence promoting uniform Zn 2+ deposition and enhancing ionic diffusion with dendrite-free growth and a reduced nucleation energy barrier. As a result, the 3DP-MPC-SiOC@Zn symmetrical cell affords a highly reversible Zn plating/stripping and dendrite-free structure over 198 h with an ultra-low voltage polarization. These inspiring performances endow the 3DP anode with a 3DP-VO cathode as a full battery, which shows a retention capacity of 78.8 mAh g -1 (Coulombic efficiency: 94.04%) at 0.1 A g -1 and a large energy density of 41 Wh kg -1 at a power density of 1.2 W kg -1 (based on the total mass of electrode) after 120 cycles. This newly developed 3D printing of hybrid composite as an electrode is straightforward and scalable and provides a novel concept for realizing dendrite-free and stable rechargeable Zn-ion batteries., (© 2024 Wiley‐VCH GmbH.)

Aqueous zinc-ion batteries (AZIBs) are highly regarded for their affordability, stability, safety, and eco-friendliness. Nevertheless, their practical application is hindered by severe side reactions and the formation of zinc (Zn) dendrites on the Zn metal anode surface. In this study, we employ tetrahydrofuran alcohol (THFA), an efficient and cost-effective alcohol ether electrolyte, to mitigate these issues and achieve ultralong-life AZIBs. Theoretical calculations and experimental findings demonstrate that THFA acts as both a hydrogen bonding donor and acceptor, effectively anchoring H 2 O molecules through dual-site hydrogen bonding. This mechanism restricts the activity of free water molecules. Moreover, the two oxygen (O) atoms in THFA serve as dual solvation sites, enhancing the desolvation kinetics of [Zn(H 2 O) 6 ] 2+ and improving the deposition dynamics of Zn 2+ ions. As a result, even trace amounts of THFA significantly suppress adverse reactions and the formation of Zn dendrites, enabling highly reversible Zn metal anodes for ultralong-life AZIBs. Specifically, a Zn-based symmetric cell containing 2 % THFA achieves an ultralong cycle life of 8,800 h at 0.5 mA cm -2 /0.5 mAh cm -2 , while a Zn//VO 2 full cell containing 2 % THFA maintains a remarkable 80.03 % capacity retention rate at 5 A g -1 over 2,000 cycles. This study presents a practical strategy to develop dendrite-free, cost-effective, and highly efficient aqueous energy storage systems by leveraging alcohol ether compounds with dual-site hydrogen bonding capabilities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Aqueous zinc-ion batteries (AZIBs) have recently been paid great attention due to their robust safety features, high theoretical capacity, and eco-friendliness, yet their practical application is hindered by the serious dendrite formation and side reactions of Zn metal anode during cycling. Herein, a low-cost small molecule, nicotinamide (NIC), is proposed as an electrolyte additive to effectively regulate the Zn interface, achieving a highly reversible and stable zinc anode without dendrites. NIC molecules not only modify the Zn 2+ solvation structure but also preferentially adsorb on the Zn surface than solvated H 2 O to protect the Zn anode and provide numerous nucleation sites for Zn 2+ to homogenize Zn deposition. Consequently, the addition of 1 wt% NIC enables Zn||Zn symmetric cells an ultra-long lifespan of over 9700 h at 1 mA cm -2 , which expands nearly 808 times compared to that without NIC. The advantages of NIC additives are further demonstrated in NaVO||Zn full cells, which exhibit exceptional capacity retention of 90.3 % after 1000 cycles with a high Coulombic efficiency of 99.9 % at 1 A/g, while the cell operates for only 42 cycles without NIC additive. This strategy presents a promising approach to solving the anode problem, fostering advancements in practical AZIBs., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Rui Li reports financial support, administrative support, equipment, drugs, or supplies, statistical analysis, and writing assistance were provided by Department of Science and Technology of Guangdong Province. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Aqueous zinc-ion batteries (AZIBs) have emerged as one of the most promising energy storage technologies due to their high safety and cost-effectiveness. However, several challenges associated with the Zn metal anode, such as dendrite growth, corrosion, and hydrogen evolution reaction (HER), have hindered further applications of AZIBs. Herein, maltose (MT) is used as a functional electrolyte additive to protect the Zn metal electrode during the interface deposition process. The additive can effectively affect the interface of Zn metal, suppressing HER and corrosion reactions. Moreover, it facilitates the uniform deposition of Zn by inducing Zn 2+ to form a stable (100) crystal plane. As a result, the symmetric cell exhibited stable cycling performance for 2000 h at a current density of 2 mA cm -2 , and the Zn||NH 4 V 4 O 10 full cell maintained steady cycling for 1000 cycles at 2 A g -1 . This study provides an approach to achieve uniform Zn deposition through additives.

Aqueous zinc-ion batteries (AZIBs) have emerged as one of the most promising candidates for next-generation energy storage devices due to their outstanding safety, cost-effectiveness, and environmental friendliness. However, the practical application of zinc metal anodes (ZMAs) faces significant challenges, such as dendrite growth, hydrogen evolution reaction, corrosion, and passivation. Fortunately, the rapid rise of nanomaterials has inspired solutions for addressing these issues associated with ZMAs. Nanomaterials with unique structural features and multifunctionality can be employed to modify ZMAs, effectively enhancing their interfacial stability and cycling reversibility. Herein, an overview of the failure mechanisms of ZMAs is presented, and the latest research progress of nanomaterials in protecting ZMAs is comprehensively summarized, including electrode structures, interfacial layers, electrolytes, and separators. Finally, a brief summary and optimistic perspective are given on the development of nanomaterials for ZMAs. This review provides a valuable reference for the rational design of efficient ZMAs and the promotion of large-scale application of AZIBs.

The highly reversible plating/stripping of Zn is plagued by dendrite growth and side reactions on metallic Zn anodes, retarding the commercial application of aqueous Zn-ion batteries. Herein, a distinctive nano dual-phase diamond (NDPD) comprised of an amorphous-crystalline heterostructure is developed to regulate Zn deposition and mechanically block dendrite growth. The rich amorphous-crystalline heterointerfaces in the NDPD endow modified Zn anodes with enhanced Zn affinity and result in homogeneous nucleation. In addition, the unparalleled hardness of the NDPD effectively overcomes the high growth stress of dendrites and mechanically impedes their proliferation. Moreover, the hydrophobic surfaces of the NDPD facilitate the desolvation of hydrate Zn 2+ and prevent water-mediated side reactions. Consequently, the Zn@NDPD presents an ultrastable lifespan exceeding 3200 h at 5 mA cm -2 and 1 mAh cm -2 . The practical application potential of Zn@NDPD is further demonstrated in full cells. This work exhibits the great significance of a chemical-mechanical synergistic anode modification strategy in constructing high-performance aqueous Zn-ion batteries.

Zinc metal suffers from violent and long-lasting water-induced side reactions and uncontrollable dendritic Zn growth, which seriously reduce the coulombic efficiency (CE) and lifespan of aqueous zinc-metal batteries (AZMBs). To suppress the corresponding harmful effects of the highly active water, a stable zirconium-based metal-organic framework with water catchers decorated inside its sub-nano channels is used to protect Zn-metal. Water catchers within narrow channels can constantly trap water molecules from the solvated Zn-ions and facilitate step-by-step desolvation/dehydration, thereby promoting the formation of an aggregative electrolyte configuration, which consequently eliminates water-induced corrosion and side reactions. More importantly, the functionalized sub-nano channels also act as ion rectifiers and promote fast but even Zn-ions transport, thereby leading to a dendrite-free Zn metal. As a result, the protected Zn metal demonstrates an unprecedented cycling stability of more than 10 000 h and an ultra-high average CE of 99.92% during 4000 cycles. More inspiringly, a practical NH 4 V 4 O 10 //Zn pouch-cell is fabricated and delivers a capacity of 98 mAh (under high cathode mass loading of 25.7 mg cm -2 ) and preserves 86.2% capacity retention after 150 cycles. This new strategy in promoting highly reversible Zn metal anodes would spur the practical utilization of AZMBs., (© 2024 Wiley‐VCH GmbH.)

Aqueous rechargeable zinc-sulfur (Zn-S) batteries are a promising, cost-effective, and high-capacity energy storage technology. Still, they are challenged by the poor reversibility of S cathodes, sluggish redox kinetics, low S utilization, and unsatisfactory areal capacity. This work develops a facile strategy to achieve an appealing high-areal-capacity (above 5 mAh cm -2 ) Zn-S battery by molecular-level regulation between S and high-electrical-conductivity tellurium (Te). The incorporation of Te as a dopant allows for manipulation of the Zn-S electrochemistry, resulting in accelerated redox conversion, and enhanced S utilization. Meanwhile, accompanied by the S-ZnS conversion, Te is converted to zinc telluride during the discharge process, as revealed by ex-situ characterizations. This additional redox reaction contributes to the S cathode's total excellent discharge capacity. With this unique cathode structure design, the carbon-confined TeS cathode (denoted as Te 1 S 7 /C) delivers a high reversible capacity of 1335.0 mAh g -1 at 0.1 A g -1 with a mass loading of 4.22 mg cm -2 , corresponding to a remarkable areal capacity of 5.64 mAh cm -2 . Notably, a hybrid electrolyte design uplifts discharge plateau, reduces overpotential, suppresses Zn dendrites growth, and extends the calendar life of Zn-Te 1 S 7 batteries. This study provides a rational S cathode structure to realize high-capacity Zn-S batteries for practical applications., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

The drawbacks of poor electronic conductivity and structural instability during the cycling process limit the electrochemical property of vanadium-based cathode materials for aqueous zinc-ion batteries. In addition, continuous growth and accumulation of zinc dendrites can puncture the separator and cause an internal short circuit in the battery. In this work, a unique multidimensional nanocomposite is designed by a facile freeze-drying method with subsequent calcination, consisting of V 2 O 3 nanosheets and single-walled carbon nanohorns (SWCNHs) crosslinked together and wrapped by reduced graphene oxide (rGO). The multidimensional structure can largely enhance the structural stability and electronic conductivity of the electrode material. Besides, additive Na 2 SO 4 in the ZnSO 4 aqueous electrolyte not only prevents the dissolution of cathode materials but also suppresses the Zn dendrite growth. After considering the influence of additive concentration on ionic conductivity and electrostatic force for electrolyte, V 2 O 3 @SWCNHs@rGO electrode delivers a high initial discharge capacity of 422 mAh g -1 at 0.2 A g -1 and a high discharge capacity of 283 mAh g -1 after 1000 cycles at 5 A g -1 in 2 m ZnSO 4 + 2 m Na 2 SO 4 electrolyte. Experimental techniques reveal that the electrochemical reaction mechanism can be expressed as the reversible phase transformation between V 2 O 5 and V 2 O 3 with Zn 3 (VO 4 ) 2 ., (© 2023 Wiley‐VCH GmbH.)

Zinc-iodine batteries have the potential to offer high energy-density aqueous energy storage, but their lifetime is limited by the rampant dendrite growth and the concurrent parasite side reactions on the Zn anode, as well as the shuttling of polyiodides. Herein, a cation-conduction dominated hydrogel electrolyte is designed to holistically enhance the stability of both zinc anode and iodine cathode. In this hydrogel electrolyte, anions are covalently anchored on hydrogel chains, and the major mobile ions in the electrolyte are restricted to be Zn 2+ . Specifically, such a cation-conductive electrolyte results in a high zinc ion transference number (0.81) within the hydrogel and guides epitaxial Zn nucleation. Furthermore, the optimized Zn 2+ solvation structure and the reconstructed hydrogen bond networks on hydrogel chains contribute to the reduced desolvation barrier and suppressed corrosion side reactions. On the iodine cathode side, the electrostatic repulsion between negative sulfonate groups and polyiodides hinders the loss of the iodine active material. This all-round electrolyte design renders zinc-iodine batteries with high reversibility, low self-discharge, and long lifespan., (© 2024 Wiley‐VCH GmbH.)

Severe dendrite growth on Zn anodes poses a significant challenge to the development of Zn-based batteries. An effective strategy for inhibiting the formation of Zn dendrites involves electrode modification. In this study, hollow nitrogen-doped carbon spheres (HNCS) are synthesized and used as electrodes to regulate Zn deposition in Zn-based flow batteries. The electrochemical performance of HNCS reveals that the pyrrole nitrogen of HNCS changes the electrode surface state. Therefore, HNCS can inhibit the hydrogen evolution reaction and achieve uniform Zn deposition. HNCS can effectively inhibit dendrite growth and improve the reversibility of the Zn plating/stripping process to regulate the reversibility of Zn-based batteries. The zinc-bromine redox flow battery assembled with HNCS significantly reduces the hydrogen evolution reaction and exhibits a coulombic efficiency of 90 % and energy efficiency of 73 % at a current density of 60 mA cm -2 . Similarly, an alkaline zinc-iron flow battery can maintain high Coulombic efficiency and energy efficiency of 83 %., (© 2024 Wiley‐VCH GmbH.)

Metallic Zn is considered as a promising anode material because of its abundance, eco-friendliness, and high theoretical capacity. However, the uncontrolled dendrite growth and side reactions restrict its further practical application. Herein, we proposed a β-cyclodextrin-modified multiwalled carbon nanotube (CD-MWCNT) layer for Zn metal anodes. The obtained CD-MWCNT layer with high affinity to Zn can significantly reduce the transfer barrier of Zn 2+ at the electrode/electrolyte interface, facilitating the uniform deposition of Zn 2+ and suppressing water-caused side reactions. Consequently, the Zn||Zn symmetric cell assembled with CD-MWCNT shows a significantly enhanced cycling durability, maintaining a cycling life exceeding 1000 h even under a high current density of 5 mA cm -2 . Furthermore, the full battery equipped with a V 2 O 5 cathode displays an unparalleled long life. This work unveils a promising avenue toward the achievement of high-performance Zn metal anodes.

The practical implementation of aqueous zinc-iodine batteries (ZIBs) is hindered by the rampant Zn dendrites growth, parasite corrosion, and polyiodide shuttling. In this work, ionic liquid EMIM[OAc] is employed as an all-round solution to mitigate challenges on both the Zn anode and the iodine cathode side. First, the EMIM + embedded lean-water inner Helmholtz plane (IHP) and inert solvation sheath modulated by OAc - effectively repels H 2 O molecules away from the Zn anode surface. The preferential adsorption of EMIM + on Zn metal facilitates uniform Zn nucleation via a steric hindrance effect. Second, EMIM + can reduce the polyiodide shuttling by hindering the iodine dissolution and forming an EMIM + -I 3 - dominated phase. These effects holistically enhance the cycle life, which is manifested by both Zn || Zn symmetric cells and Zn-I 2 full cells. ZIBs with EAc deliver a capacity decay rate of merely 0.01 ‰ per cycle after over 18,000 cycles at 4 A g -1 , and lower self-discharge and better calendar life than the ZIBs without ionic liquid EAc additive., (© 2024 Wiley-VCH GmbH.)

With the increasing demand for low-cost and high-safety portable batteries, aqueous zinc-ion batteries (ZIBs) have been regarded as a potential alternative to the lithium-ion batteries, bringing about extensive research dedicated in the exploration of high-performance and highly reversible ZIBs. Although separators are generally considered as non-active components in conventional research on ZIBs, advanced separators designs seem to offer effective solutions to the majority of issues within ZIBs system. These issues encompass concerns related to the zinc anode, cathode, and electrolyte. Initially, we delve into the origins and implications of various inherent problems within the ZIBs system. Subsequently, we present the latest research advancements in addressing these challenges through separators engineering. This includes a comprehensive, detailed exploration of various strategies, coupled with instances of advanced characterizations to provide a more profound insight into the mechanisms that influence the separators. Finally, we undertake a multi-criteria evaluation, based on application standards for diverse substrate separators, while proposing guiding principles for the optimal design of separators in zinc batteries. This review aims to furnish valuable guidance for the future development of advanced separators, thereby nurturing progress in the field of ZIBs., (© 2023 Wiley-VCH GmbH.)

Zinc ion batteries are considered as potential energy storage devices due to their advantages of low-cost, high-safety, and high theoretical capacity. However, dendrite growth and chemical corrosion occurring on Zn anode limit their commercialization. These problems can be tackled through the optimization of the electrolyte. However, the screening of electrolyte additives using normal electrochemical methods is time-consuming and labor-intensive. Herein, a fast and simple method based on the digital holography is developed. It can realize the in situ monitoring of electrode/electrolyte interface and provide direct information concerning ion concentration evolution of the diffusion layer. It is effective and time-saving in estimating the homogeneity of the deposition layer and predicting the tendency of dendrite growth, thus able to value the applicability of electrolyte additives. The feasibility of this method is further validated by the forecast and evaluation of thioacetamide additive. Based on systematic characterization, it is proved that the introduction of thioacetamide can not only regulate the interficial ion flux to induce dendrite-free Zn deposition, but also construct adsorption molecule layers to inhibit side reactions of Zn anode. Being easy to operate, capable of in situ observation, and able to endure harsh conditions, digital holography method will be a promising approach for the interfacial investigation of other battery systems., (© 2024. The Author(s).)

Rampant dendrite growth, electrode passivation and severe corrosion originate from the uncontrolled ions migration behavior of Zn 2+ , SO 4 2- , and H + , which are largely compromising the aqueous zinc ion batteries (AZIBs) performance. Exploring the ultimate strategy to eliminate all the Zn anode issues is challenging but urgent at present. Herein, a fluorinated separator interface (PVDF@GF) is constructed simply by grafting the polyvinylidene difluoride (PVDF) on the GF surface to realize high-performance AZIBs. Experimental and theoretical studies reveal that the strong interaction between C─F bonds in the PVDF and Zn 2+ ions enables evenly redistributed Zn 2+ ions concentration at the electrode interface and accelerates the Zn transportation kinetics, leading to homogeneous and fast Zn deposition. Furthermore, the electronegative separator interface can spontaneously repel the SO 4 2- and anchor H + ions to alleviate the passivation and corrosion. Accordingly, the Zn|Zn symmetric cell with PVDF@GF harvests a superior cycling stability of 500 h at 10 mAh cm -2 , and the Zn|VOX full cell delivers 76.8% capacity retention after 1000 cycles at 2 A g -1 . This work offers an all-round solution and provides new insights for the design of advanced separators with ionic sieve function toward stable and reversible Zn metal anode chemistry., (© 2023 Wiley-VCH GmbH.)

Aqueous rechargeable zinc-based batteries (ZBBs) are emerging as desirable energy storage systems because of their high capacity, low cost, and inherent safety. However, the further application of ZBBs still faces many challenges, such as the issues of uncontrolled dendrite growth and severe parasitic reactions occurring at the Zn anode. Herein, an amino-grafted bacterial cellulose (NBC) film is prepared as artificial solid electrolyte interphase (SEI) for the Zn metal anodes, which can significantly reduce zinc nucleation overpotential and lead to the dendrite-free deposition of Zn metal along the (002) crystal plane more easily without any external stimulus. More importantly, the chelation between the modified amino groups and zinc ions can promote the formation of an ultra-even amorphous SEI upon cycling, reducing the activity of hydrate ions, and inhibiting the water-induced side reactions. As a result, the Zn||Zn symmetric cell with NBC film exhibits lower overpotential and higher cyclic stability. When coupled with the V 2 O 5 cathode, the practical pouch cell achieves superior electrochemical performance over 1000 cycles., (© 2023 Wiley-VCH GmbH.)

Research on zinc-ion batteries (ZIBs) with manganese-based cathodes has been severely hindered by their poor cycle stability. This study explores the fundamental parameters that affect the cycle stability of battery systems from a structural stability perspective. MnO 2 electrodes with different classical morphologies and sizes were synthesized via a temperature-controlled coprecipitation strategy. The effects of the morphology and size of the MnO 2 on the overall electrical properties and kinetics of ZIBs were analyzed and compared. The one-dimensional nanofibrous α-MnO 2 produced using this method exhibited the most stable nanostructure with a favorable aspect ratio, which resulted in faster chemical kinetics. A more uniform particle distribution and better aspect ratios not only enabled a faster ion migration rate but also affected the remolding of the anode morphology. After 2000 cycles at a high current density of 1 A g -1 , the material maintained an excellent discharge-specific capacity, highlighting it as a promising electrode material for ZIBs. The construction of nanoenergy materials with controllable morphologies and sizes will significantly advance battery applications.

The operating temperature of batteries is an essential consideration in actual applications. Understanding the temperature dependence is conducive to battery design. The experience in lithium-ion batteries (LIBs) indicates that the dendrite issue is exacerbated at lower temperatures and suppressed at higher temperatures. In this study, we revealed the dendrite evolution in aqueous rechargeable zinc-based batteries (RZBs), for which the opposite temperature dependence was observed. Detailed investigations elucidate that the degree of matching of the interface reaction rate and ion diffusivity, together with side reactions, are the key factors that determine the cycling performance. The different properties of organic and aqueous electrolytes result in a reversed temperature dependence. We further conducted a detailed investigation of hybrid electrolytes (organic and aqueous) for balancing the ion diffusivity and side reactions to broaden the working temperature window for RZBs. This work reveals a completely opposite temperature dependence for LIBs and RZBs and discloses the underlying mechanism, reminding one of the differences between LIBs and RZBs in many aspects., Competing Interests: Conflict of interest The authors declare that they have no conflict of interest., (Copyright © 2023 Science China Press. Published by Elsevier B.V. All rights reserved.)

Rechargeable aqueous zinc-ion batteries (ZIB) sparked a considerable surge of research attention in energy storage systems due to its environment benignity and superior electrochemical performance. Up to now, less efforts to delve into mechanisms of zinc metal anode and their electrochemical performance. Zn metal anodes sustain thorny issues with Zn dendrite growth, hydrogen evolution reaction, and Zn corrosion irreversible byproduct formation, which results in low coulomb efficiency (CE) and poor cycle ability of the battery. Herein, we reveal the fundamental understanding of the above issue, outline four step, including mass transfer, desolvation process, charge transfer and Zn cluster formation. It can be clearly seen from reported strategies to promote Zn anode stability that deals with one or more steps, thereby boosting the understanding of the issues of Zn anodes and benefiting the rational design to surmount the issue. We also sum up advanced materials and structure design such as the design of the anode surface and internal structure, electrolyte strategies, and multifunctional separators. Finally, possible tactics and future innovation direction for Zn-based batteries are proposed to achieve high performance aqueous Zinc-ion batteries., (© 2023 The Chemical Society of Japan & Wiley-VCH GmbH.)

Herein, an efficient method to prepare sulfonated polyether ether ketone (SPEEK) based cation exchange membranes (CEMs) is developed, where polyethersulfone (PES) is used as an additive. The optimized membrane of 30 wt.%PES/SPEEK-M exhibits a rather low anion permeability and a high ionic conductivity of 9.52 mS cm -1 together with low volume swelling in water. Meanwhile, tensile strength of the membrane is as high as 31.4 MPa with a tensile strain of 162%. As separators for aqueous K-ion batteries (AKIBs) with decoupled gel electrolytes (Zn anode in alkaline and Prussian blue (FeHCF) cathode in neutral). Discharge voltage of the AKIB can reach 2.3 V. Meanwhile, Zn dendrites can be effectively suppressed in the gel anolyte. Specific capacities of the FeHCF cathode are 116.7 mAh g -1 at 0.3 A g -1 (close to its theoretical value), and 95.0 mAh g -1 at 1.0 A g -1 , indicating good rate performance. Capacity retention of the cathode is as high as 91.2% after 1000 cycles' cycling owing to the well remained neutral environment of the catholyte. There is almost no pH change for the catholyte after cycling, indicating good anion-blocking or cation-selecting ability of the 30 wt.%PES/SPEEK-M, much better than other membranes., (© 2022 Wiley-VCH GmbH.)

Alkaline nickel-zinc (Ni-Zn) batteries, as traditional rechargeable aqueous batteries, possess an obvious advantage in terms of energy density, but their development has been hindered by the anode-concerned problems, Zn dendrites, self-corrosion, passivation, deformation, and hydrogen evolution reaction (HER). Herein, to solve these problems, a dual protective strategy is proposed toward the anode using ZnO as an initial active material, including a C coating on ZnO (ZnO@C) and a thin poly(vinyl alcohol) (PVA) layer coating on the electrode (ZnO@C-PVA). In a three-electrode configuration, the reversible capacity can reach 600 mAh g -1 for the ZnO@C-PVA. Using excessive commercial Ni(OH) 2 as the cathode, the alkaline Ni-Zn cells exhibit good electrochemical performance: Discharge capacity can be as high as 640-650 mAh g -1 at 4 A g -1 with a Coulomb efficiency (CE) as high as 97-99% after activity, suggesting low self-corrosion and HER. Capacity retention is 97% after 1200 cycles, indicating rather good durability. The discharge capacity is even slightly increased with the increase of charge/discharge current density (≤8 A g -1 ), implying good rate performance. Additionally, the discharge voltage can reach 1.8 V (midpoint value) at various current densities, reflecting the fast reaction kinetics of the anode. Most importantly, no Zn dendrites and passivation are observed after long-term cycling. The strategy proposed here can solve the anode-concerned problems effectively, exhibiting a high application prospect.

The development of aqueous zinc-ion batteries (AZIBs) has been severely restricted by metallic Zn anode issues, including Zn dendrites and uncontrollable side reactions. The direct interfacial modification of a Zn anode is a facile and effective strategy that has been favored by researchers. Herein, we propose an acrylic-bonded stationary layer as an artificial solid electrolyte interface (SEI) for the Zn anode to manipulate the Zn plating/stripping. The constructed modification layer is made of zinc acrylate cross-linked to form a three-dimensional (3D) porous structure, which can induce uniform deposition of zinc ions and balance the local electric field, thus achieving homogeneous nucleation and uniform Zn deposition. More importantly, this fabricated layer is chemically bonded to the zinc surface and can tolerate prolonged zinc deposition without shedding compared with conventional physical coatings. Consequently, the Zn/Zn symmetric cells, Zn/Na 0.92 V 2 O 5 · n H 2 O (NaVO) full cells, and Zn hybrid supercapacitors using this acrylic-bonded modified anode demonstrate greatly improved cycle performance.

Aqueous zinc-ion batteries (AZIBs) with high safety and low cost are considered to be one of the alternatives to Li-ion batteries. In recent years, AZIBs have become a research hotspot, mainly focusing on the research of cathode, anode and electrolyte. Although many efforts have been made in cathode materials, their low specific capacity and poor cycle life remain unsolved. In fact, side reactions of zinc metal anodes, such as dendrite growth, zinc corrosion, and hydrogen evolution reactions (HER), are also the main factors restricting the electrochemical performance of AZIBs. In this review, we first discuss the fundamental of these adverse reactions. Then, the various solution strategies are summarized based on advanced materials and structural design. It includes surface modification and the internal structure optimization of Zn electrodes, the regulation of electrolytes and separators. Finally, we propose the future challenges and development prospects of zinc anode., (© 2022 The Chemical Society of Japan & Wiley-VCH GmbH.)

Rechargeable Zn-based batteries (RZBs) have garnered a great interest and are thought to be among the most promising options for next-generation energy storage technologies due to their low price, high levels of safety, adequate energy density and environmental friendliness. However, dendrite formation during stripping/plating prevents rechargeable zinc-based batteries from being used in real-world applications. Dendrite formation is still a concern, despite the fact that inhibitory strategies have been put up recently to eliminate the harmful effects of zinc dendrites. Thus, in order to direct the strategies for inhibiting zinc dendrite growth, it is vital to understand the formation mechanism of zinc dendrites. Hence, for the practical application of zinc-based batteries, is essential to use techniques that effectively prevent the creation and growth of zinc dendrites. The development and growth principles of zinc dendrites are first made clear in this review. The recent advances of solutions to the zinc dendrite problem are then discussed, including strategies to prevent dendrite growth and subsequent creation as much as possible, reduce the negative impacts of dendrites, and create dendrite-free deposition processes. Finally, the challenges and perspective for the development of zinc-based batteries are discussed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Worku.)

Aqueous zinc-ion batteries (ZIBs) have been extensively studied due to their inherent safety and high energy density for large-scale energy storage. However, the practical application is significantly limited by the growing Zn dendrites on metallic Zn anode during cycling. Herein, an environmental biomolecular electrolyte additive, fibroin (FI), is proposed to guide the homogeneous Zn deposition and stabilize Zn anode. This work demonstrates that the FI molecules with abundant electron-rich groups (NH, OH, and CO) can anchor on Zn anode surface to provide more nucleation sites and suppress the side reactions, and the strong interaction with water molecules can simultaneously regulate the Zn 2+ coordination environment facilitating the uniform deposition of Zn. As a consequence, only 0.5 wt% FI additive enables a highly reversible Zn plating/stripping over 4000 h at 1 mA cm -2 , indicating a sufficient advance in performance over state-of-the-art Zn anodes. Furthermore, when applied to a full battery (NaVO/Zn), the cell exhibits excellent capacity retention of 98.4% after 1000 cycles as well as high Coulombic efficiency of 99%, whereas the cell only operates for 68 cycles without FI additive. This work offers a non-toxic, low-cost, effective additive strategy to solve dendrites problems and achieve long-life and high-performance rechargeable aqueous ZIBs., (© 2022 Wiley-VCH GmbH.)

The interface plays a pivotal role in stabilizing metal anode. Extensive studies have been made but systematic research is lacking. In this study, preliminary studies are conducted to explore the prime conditions of interfacial modification to approach the practical requirements. Critical factors including reaction kinetics, transport rate, and modulus are identified to affect the Zn anode morphology significantly. The fundamental principle to enhance the Zn anode stability is systematically studied using the TEMPO-oxidized cellulose nanofiber (TOCNF) coating layer with thin a separator. Its advantageous mechanical properties buffer the huge volume variation. The existence of hydrophilic TOCNF in the Zn anode interface enhances the mass transfer process and alters the Zn 2+ distribution with a record high double-layer capacitance (390 uF cm -2 ). With the synergetic effect, the modified Zn anode works stably under 5 mA cm -2 with a thin nonwoven paper as the separator (thickness 113 µm). At an ultra-high current density of 10 mA cm -2 , this coated anode cycles for more than 300 h. This strategy shows an immense potential to drive the Zn anode forward toward practical applications., (© 2022 Wiley-VCH GmbH.)

Tip-induced dendrites on metallic zinc anodes (MZAs) fundamentally deteriorate the rechargeability of aqueous Zn metal batteries (ZMBs). Herein, an intriguing ion sieve (IS) consisting of 3D intertwined bacterial cellulose, deposited on the surface of MZAs (Zn@IS) through an in situ self-assembly route, is first presented to be effective in inhibiting dendrite-growth on MZAs. Experimental analyses together with theoretical calculations suggested that the IS coating can facilitate the desolvation of [Zn(H 2 O) 6 ] 2+ clusters via a strong interplay with Zn ions, weaken hydrogen evolution reaction of MZAs, and homogenize the ion flux with the abundant nanopores serving as ion tunnels, synergistically enabling dendrite-free Zn deposition on the Zn@IS anodes. Consequently, a lifespan up to 3000 h at a cutoff capacity of 0.25 mA h cm -2 was observed in a Zn@IS ∥ Zn@IS symmetric cell. In terms of application, pairing with a carbon-nanotube@MnO 2 cathode as an example, the full ZMBs acquired enhanced rechargeability with much higher capacity retention over 73.3% after 3000 cycles compared to the counterpart with pristine MZA (21%).

The zinc (Zn)-ion battery has attracted much attention due to its high safety and environmental protection. At present, the critical issues of the generation of dendrites and the accumulation of dead Zn on the surface will lead to a sharp decline of the battery life. Zn dendrites can be inhibited to some extent by constructing an interface protective coating. However, the existing rigid coating method cannot maintain conformal contact with Zn due to the volume change of Zn deposition and will cause fracture irreversibly during the cycle. Here, a highly self-adaptable poly(dimethylsiloxane) (PDMS)/TiO 2- x coating is developed that can dynamically adapt to volume changes and inhibit dendrites growth. PDMS has high dynamic and self-adaptability due to the crosslinking of the B-O bond. In addition, the rapid and uniform transfer of Zn 2+ is induced by the oxygen-vacancy-rich TiO 2- x . The assembled cells still achieve 99.6% coulombic efficiency after 700 cycles at a current density of 10 mA cm -2 . The adaptive interface coating constructed provides a sufficient guarantee for the stable operation of the Zn anode., (© 2021 Wiley-VCH GmbH.)

Metallic zinc (Zn) has been considered to be an ideal anode material for aqueous batteries, but is impeded by the growth of Zn dendrites and its side reactions with an aqueous electrolyte. Here, it is reported that an artificial protective layer filled with novel 2D Zn 2+ adsorbed Sb 3 P 2 O 14 3- (denoted as Zn-Sb 3 P 2 O 14 ) nanosheets provide an effective route to mitigate the above challenging problems. The Zn-Sb 3 P 2 O 14 protection layer not only avoids the direct contact with the aqueous electrolyte to suppress the side reactions but also allows for Zn-ions to pass through the protection layer rapidly. Moreover, the 2D Sb 3 P 2 O 14 3- skeleton with negative charge also confines the 2D diffusion of Zn-ion along the lateral surface of Zn anode, resulting in a uniform electron-deposition. This unique protection layer not only enables dendrite-free Zn plating/stripping with an average Coulombic efficiency of 99.2% for 200 cycles, but also sustains the symmetric Zn||Zn cell over 1300 h at 1 mA cm -2 and 1 mAh cm -2 as well as for 450 h at 10 mA cm -2 and 10 mAh cm -2 . Such advantages bring high reversibility to full Zn batteries with MnO 2 cathodes, which deliver a discharge capacity of 111.7 mAh g -1 after 1000 cycles., (© 2021 Wiley-VCH GmbH.)

Aqueous Zn batteries that provide a synergistic integration of absolute safety and high energy density have been considered as highly promising energy-storage systems for powering electronics. Despite the rapid progress made in developing high-performance cathodes and electrolytes, the underestimated but non-negligible dendrites of Zn anode have been observed to shorten battery lifespan. Herein, this dendrite issue in Zn anodes, with regard to fundamentals, protection strategies, characterization techniques, and theoretical simulations, is systematically discussed. An overall comparison between the Zn dendrite and its Li and Al counterparts, to highlight their differences in both origin and topology, is given. Subsequently, in-depth clarifications of the specific influence factors of Zn dendrites, including the accumulation effect and the cathode loading mass (a distinct factor for laboratory studies and practical applications) are presented. Recent advances in Zn dendrite protection are then comprehensively summarized and categorized to generate an overview of respective superiorities and limitations of various strategies. Accordingly, theoretical computations and advanced characterization approaches are introduced as mechanism guidelines and measurement criteria for dendrite suppression, respectively. The concluding section emphasizes future challenges in addressing the Zn dendrite issue and potential approaches to further promoting the lifespan of Zn batteries., (© 2020 Wiley-VCH GmbH.)

Aqueous rechargeable Zn/birnessite batteries have recently attracted extensive attention for energy storage system because of their low cost and high safety. However, the reaction mechanism of the birnessite cathode in aqueous electrolytes and the cathode structure degradation mechanics still remain elusive and controversial. In this work, it is found that solvation water molecules coordinated to Zn 2+ are coinserted into birnessite lattice structure contributing to Zn 2+ diffusion. However, the birnessite will suffer from hydroxylation and Mn dissolution with too much solvated water coinsertion. Through engineering Zn 2+ primary solvation sheath with strong-field ligand in aqueous electrolyte, highly reversible [Zn(H 2 O) 2 ] 2+ complex intercalation/extraction into/from birnessite cathode is obtained. Cathode-electrolyte interface suppressing the Mn dissolution also forms. The Zn metal anode also shows high reversibility without formation of "death-zinc" and detrimental dendrite. A full cell coupled with birnessite cathode and Zn metal anode delivers a discharge capacity of 270 mAh g -1 , a high energy density of 280 Wh kg -1 (based on total mass of cathode and anode active materials), and capacity retention of 90% over 5000 cycles., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Current aqueous Zn batteries (ZBs) seriously suffer from dendrite issues caused by rough electrode surfaces. Despite significant efforts in prolonging lifespan of these batteries, little effort has been devoted to dendrite elimination in commercial-grade cathode loading mass. Instead, demonstrations have only been done at the laboratory level (≤2 mg cm -2 ). Additionally, new dilemmas regarding change of the proton-storage behavior and interface pulverization have emerged in turn. Herein, hydrogen-substituted graphdiyne (HsGDY), with sub-ångström level ion tunnels and robust chemical stability, is designed as an artificial interface layer to address these issues. This strategy prolongs the symmetric cell lifespan to >2400 h (100 days), which is 37 times larger than without protection (63 h). The simulation of dual fields reveals that HsGDY can redistribute the Zn 2+ concentration field by spatially forcing Zn 2+ to deviate from the irregular electric field. During practical use, the as-assembled full batteries deliver a long lifespan 50 000 cycles and remain stable even at a commercial-grade cathode loading mass of up to 22.95 mg cm -2 . This HsGDY-protection methodology represents great progress in Zn dendrite protection and demonstrates enormous potential in metal batteries., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Rechargeable zinc (Zn) batteries suffer from poor cycling performance that can be attributed to dendrite growth and surface-originated side reactions. Herein, we report that cycling performance of Zn metal anode can be improved significantly by utilizing monolayer graphene (Gr) as the electrodeposition substrate. Utilizing microscopy and X-ray diffraction techniques, we demonstrate that electrodeposited Zn on Gr substrate has a compact, uniform, and nondendritic character. The Gr layer, due to its high lattice compatibility with Zn, provides low nucleation overpotential sites for Zn electrodeposition. Atomistic calculations indicate that Gr has strong affinity to Zn (binding energy of 4.41 eV for Gr with four defect sites), leading to uniform distribution of Zinc adatoms all over the Gr surface. This synergistic compatibility between Gr and Zn promotes subsequent homogeneous and planar Zn deposits with low interfacial energy (0.212 J/m 2 ) conformal with the current collector surface.

The dendritic issue in aqueous zinc-ion batteries (ZBs) using neutral/mild electrolytes has remained an intensive controversy for a long time: some researchers assert that dendrites severely exist while others claim great cycling stability without any protection. This issue is clarified by investigating charge/discharge-condition-dependent formation of Zn dendrites. Lifespan degradation (120 to 1.2 h) and voltage hysteresis deterioration (134 to 380 mV) are observed with increased current densities due to the formation of Zn dendrites (edge size: 0.69-4.37 µm). In addition, the capacity is also found to remarkably affect the appearance of the dendrites as well. Therefore, at small current densities or loading mass, Zn dendrites might not be an issue, while the large conditions may rapidly ruin batteries. Based on this discovery, a first-in-class electrohealing methodology is developed to eliminate already-formed dendrites, generating extremely prolonged lifespans by 410% at 7.5 mA cm -2 and 516% at 10 mA cm -2 . Morphological analysis reveals that vertically aligned Zn dendrites with sharp tips gradually become passivated and finally generate a smooth surface. This developed electrohealing strategy may promote research on metal dendrites in various batteries evolving from passive prevention to active elimination, rescuing in-service batteries in situ to achieve elongated lifetime., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)