Water molecules and oxygen-vacancy modulation of vanadium pentoxide with fast kinetics toward ultrahigh power density and durable flexible all-solid-state zinc ion battery

Aqueous zinc ion battery(ZIB)with many virtues such as high safety,cost-effective,and good environmental compatibility is a large-scale energy storage technology with great application potential.Nevertheless,its application is severely hindered by the slow diffusion of zinc ions in desirable cathode materials.Herein,a technique of water-incorporation coupled with oxygen-vacancy modulation is exploited to improve the zinc ions diffusion kinetics in vanadium pentoxide(V_(2)O_5)cathode for ZIB.The incorporated water molecules replace lattice oxygen in V_(2)O_5,and function as pillars to expand interlayer distance.So the structural stability can be enhanced,and the zinc ions diffusion kinetics might also be promoted during the repeated intercalation/deintercalation.Meanwhile,the lattice water molecules can effectively enhance conductivity due to the electronic density modulation effect.Consequently,the modulated V_(2)O_5(H-V_(2)O_5)cathode behaves with superior rate capacity and stable durability,achieving 234 mA h g^(-1)over 9000 cycles even at 20 A g^(-1).Furthermore,a flexible all-solid-state(ASS)ZIB has been constructed,exhibiting an admirable energy density of 196.6 Wh kg^(-1)and impressive power density of 20.4 kW kg^(-1)as well as excellent long-term lifespan.Importantly,the assembled flexible ASS ZIB would be able to work in a large temperature span(from-20 to 70℃).Additionally,we also uncover the energy storage mechanism of the H-V_(2)O_5 electrode,offering a novel approach for creating high-kinetics cathodes for multivalent ion storage.

β-MnO_(2) with proton conversion mechanism in rechargeable zinc ion battery

Rechargeable aqueous zinc ion battery(RAZIB)is a promising energy storage system due to its high safety,and high capacity.Among them,manganese oxides with low cost and low toxicity have drawn much attention.However,the under-debate proton reaction mechanism and unsatisfactory electrochemical performance limit their applications.Nanorod b-MnO_(2) synthesized by hydrothermal method is used to investigate the reaction mechanism.As cathode materials for RAZIB,the Zn//b-MnO_(2) delivers 355 mA h g^(-1)(based on cathode mass)at0.1 A g^(-1),and retain 110 mA h g^(-1) after 1000 cycles at 0.2 A g^(-1).Different from conventional zinc ion insertion/extraction mechanism,the proton conversion and Mn ion dissolution/deposition mechanism of b-MnO_(2) is proposed by analyzing the evolution of phase,structure,morphology,and element of b-MnO_(2) electrode,the pH change of electrolyte and the determination of intermediate phase MnO OH.Zinc ion,as a kind of Lewis acid,also provides protons through the formation of ZHS in the proton reaction process.This study of reaction mechanism provides a new perspective for the development of Zn//MnO_(2) battery chemistry.

High rate and ultralong life flexible all-solid-state zinc ion battery based on electron density modulated NiCo_(2)O_(4) nanosheets

The development of zinc ion batteries (ZIBs) with large capacity,high rate,and durable cathode material is a crucial and urgent task.Ni Co_(2)O_(4)(NCO) has received ever-growing interest as a potential cathode material for ZIBs,owing to the high theoretical capacity,rich source,cost-effective,and versatile redox nature.However,due to the slow dynamics of the NCO electrodes,its practical application in highperformance systems is severely limited.Herein,we report an electron density modulated NCO nanosheets (N-NCO NSs) with high-kinetics Zn^(2+)-storage capability as an additive-free cathode for flexible all-solid-state (ASS) ZIBs.By virtue of the enhanced electronic conductivity,improved reaction kinetics,and increased active sites,the optimized N-NCO NSs electrode delivers a high capacity of 357.7 m Ah g^(-1)at 1.0 A g^(-1)and a superior rate capacity of 201.4 m Ah g^(-1)at 20 A g^(-1).More importantly,a flexible ASS ZIBs device is manufactured using a solid polymer electrolyte of a poly (vinylidene fluoride hexafluoropropylene)(PVDF-HFP) film.The flexible ASS ZIBs device shows superb durability with 80.2%capacity retention after 20,000 cycles and works well in the range of-20–70℃.Furthermore,the flexible ASS ZIBs achieves an impressive energy density as high as 578.1 W h kg^(-1)with a peak power density of 33.6 k W kg^(-1),substantially outperforming those latest ZIBs.This work could provide valuable insights for constructing high-kinetics and high-capability cathodes with long-term stability for flexible ASS ZIBs.

Novel high-voltage cathode for aqueous zinc ion batteries:Porous K_(0.5)VOPO_(4)·1.5H_(2)O with reversible solid-solution intercalation and conversion storage mechanism

Cathode materials that possess high output voltage,as well as those that can be mass-produced using facile techniques,are crucial for the advancement of aqueous zinc-ion battery(ZIBs)applications,Herein,we present for the first time a new porous K_(0.5)VOPO_(4)·1.5H_(2)O polyanionic cathode(P-KIVP)with high output voltage(above 1.2 V)that can be manufactured at room temperature using straightforward coprecipitation and etching techniques.The P-KVP cathode experiences anisotropic crystal plane expansion via a sequential solid-solution intercalation and phase co nversion pathway throughout the Zn^(2+)storage process,as confirmed by in-situ synchrotron X-ray diffraction and ex-situ X-ray photoelectron spectroscopy.Similar to other layered vanadium-based polyanionic materials,the P-KVP cathode experiences a progressive decline in voltage during the cycle,which is demonstrated to be caused by the irreversible conversion into amorphous VO_(x).By introducing a new electrolyte containing Zn(OTF)_(2) to a mixed triethyl phosphate and water solution,it is possible to impede this irreversible conversion and obtain a high output voltage and longer cycle life by forming a P-rich cathode electrolyte interface layer.As a proof-of-concept,the flexible fiber-shaped ZIBs based on modified electrolyte woven into a fabric watch band can power an electronic watch,highlighting the application potential of P-KVP cathode.

Amorphous nickel borate nanosheets as cathode material with high capacity and better cycling performance for zinc ion battery

Zinc-ion batteries are under current research focus because of their uniqueness in low cost and high safety.However,the pursuing of high-performance cathode materials of aqueous Zinc ion batteries(AZBs)with low cost,high energy density and long cycle life has become the key problem to be solved.Herein we synthesized a series of amorphous nickel borate(AM-NiBO)nanosheets by varying corrosion time with in-situ electrochemical corrosion method.The AM-NiBO-T13 as electrode material possesses a high areal capacity of 0.65 m Ah/cm^(2) with the capacity retention of 95.1%after 2000 cycles.In addition,the assembled AM-NiBO-T13//Zn provides high energy density(0.77 m Wh/cm^(2) at 1.76 m W/cm^(2)).The high areal capacity and better cycling performance can be owing to the amorphous nanosheets structure and the stable coordination characteristics of boron and oxygen in borate materials.It shows that amorphous nickel borate nanosheets have great prospects in the field of energy storage.

Ti_(3)C_(2)T_(x)-TiSe_(2) analogous heterostructure for flexible zinc ion battery

Exploring zinc-free anode materials is one of the effective strategies to get the zinc dendrites problem of flexible zinc ion battery(ZIB)solved.In this work,an analogous heterostructure(AHS)is constructed from the excellent MXene(Ti_(3)C_(2)T_(x))and TiSe_(2) nanosheets.The AHS not only possesses numerous diffu-sion paths and Zn^(2+)storage sites but also possesses a stable conductive network to accelerate charge transfer in the electrode.As a collaborative advantage,electrochemical measurement results show that MXene/TiSe_(2) electrodes display an excellent specific capacity of 177.9 mAh g^(-1) at 0.10 A g^(-1) and a long-term cycling stability of 77.4%capacity retention after 400 cycles.DFT computations further demon-strate the excellent performance of MXene/TiSe_(2) electrodes including desirable electronic conductivity and low Zn^(2+)migration barriers.The assembled flexible ZIB not only delivers a good specific capacity of 42.2μAh cm^(-2) at 0.20 mA cm^(-2) and a competitive energy density of 37.4μWh cm^(-2) but also exhibits excellent flexibility and thermostability.Furthermore,after 400 cycles at 0.60 A g^(-1),flexible ZIB shows a capacity retention of 73.8%.This work gives a successful attempt to design 2D layered materials as Zn metal-free anode for flexible ZIB.

Polymer engineering for electrodes of aqueous zinc ion batteries

With the increasing demand for scalable and cost-effective electrochemical energy storage,aqueous zinc ion batteries(AZIBs)have a broad application prospect as an inexpensive,efficient,and naturally secure energy storage device.However,the limitations suffered by AZIBs,including volume expansion and active materials dissolution of the cathode,electrochemical corrosion,irreversible side reactions,zinc dendrites of the anode,have seriously decelerated the civilianization process of AZIBs.Currently,polymers have tremendous superiority for application in AZIBs attributed to their exceptional chemical stability,tunable structure,high energy density and outstanding mechanical properties.Considering the expanding applications of AZIBs and the superiority of polymers,this comprehensive paper meticulously reviews the benefits of utilizing polymeric applied to cathodes and anodes,respectively.To begin with,with adjustable structure as an entry point,the correlation between polymer structure and the function of energy storage as well as optimization is deeply investigated in respect to the mechanism.Then,depending on the diversity of properties and structures,the development of polymers in AZIBs is summarized,including conductive polymers,redox polymers as well as carbon composite polymers for cathode and polyvinylidene fluoride-,carbonyl-,amino-,nitrile-based polymers for anode,and a comprehensive evaluation of the shortcomings of these strategies is provided.Finally,an outlook highlights some of the challenges posed by the application of polymers and offers insights into the potential future direction of polymers in AZIBs.It is designed to provide a thorough reference for researchers and developers working on polymer for AZIBs.

Regulating interfacial behavior of zinc metal anode via metal-organic framework functionalized separator

Aqueous zinc ion batteries(AZIBs)are one of the promising energy storage devices.However,uncontrolled dendrite and side reactions have seriously hindered its further application.In this study,the metal-organic framework(MOF)functionalized glass fiber separator(GF-PFC-31)was used to regulate interfacial behavior of zinc metal anode,enabling the development of high-performance AZIBs.In PFC-31,there areπ-πinteractions between two adjacent benzene rings with a spacing of 3.199 A.This spacing can block the passage of[Zn(H_(2)O)_6]^(2+)(8.6 A in diameter)through the GF-PFC-31 separator to a certain extent,which promotes the deposition process of Zn ions.In addition,the sulfonic acid group(-S03H)contained in GF-PFC-31 can form a hydrogen bonding network with H_(2)O,which can provide a desolvation effect and reduce the side reaction.Consequently,GF-PFC-31 separator achieves uniform deposition of Zn ions.The Zn‖GF-PFC-31‖Zn symmetric cell exhibits stable cycle life(3000 h at 1.2 mA cm^(-2),2000 h at 0.3 mA cm^(-2),and 2000 h at 5.0 mA cm^(-2)),and Zn‖GF-PFC-31‖MnO_(2) full cell with GF-PFC-31 separator can cycle for 1000 cycles at 1.2 A g^(-1)with capacity retention rate of 82.5%.This work provides a promising method to achieve high-performance AZIBs.

Revealing the role of calcium ion intercalation of hydrated vanadium oxides for aqueous zinc-ion batteries

Exploring suitable high-capacity V_(2)O_(5)-based cathode materials is essential for the rapid advancement of aqueous zinc ion batteries(ZIBs).However,the typical problem of slow Zn^(2+)diffusion kinetics has severely limited the feasibility of such materials.In this work,unique hydrated vanadates(CaVO,BaVO)were obtained by intercalation of Ca^(2+)or Ba^(2+)into hydrated vanadium pentoxide.In the CaVO//Zn and BaVO//Zn batteries systems,the former delivered up to a 489.8 mAh g^(-1)discharge specific capacity at 0.1 A g^(-1).Moreover,the remarkable energy density of 370.07 Wh kg^(-1)and favorable cycling stability yard outperform BaVO,pure V_(2)O_(5),and many reported cathodes of similar ionic intercalation compounds.In addition,pseudocapacitance analysis,galvanostatic intermittent titration(GITT)tests,and Trasatti analysis revealed the high capacitance contribution and Zn^(2+)diffusion coefficient of CaVO,while an in-depth investigation based on EIS elucidated the reasons for the better electrochemical performance of CaVO.Notably,ex-situ XRD,XPS,and TEM tests further demonstrated the Zn^(2+)insertion/extraction and Zn-storage mechanism that occurred during the cycle in the CaVO//Zn battery system.This work provides new insights into the intercalation of similar divalent cations in vanadium oxides and offers new solutions for designing cathodes for high-capacity aqueous ZIBs.

Recent advances and perspectives of zinc metal-free anodes for zinc ion batteries

Zinc-ion batteries(ZIBs) are recognized as potential energy storage devices due to their advantages of low cost, high energy density, and environmental friendliness. However, zinc anodes are subject to unavoidable zinc dendrites, passivation, corrosion, and hydrogen evolution reactions during the charging and discharging of batteries, becoming obstacles to the practical application of ZIBs. Appropriate zinc metal-free anodes provide a higher working potential than metallic zinc anodes, effectively solving the problems of zinc dendrites, hydrogen evolution, and side reactions during the operation of metallic zinc anodes. The improvement in the safety and cycle life of batteries creates conditions for further commercialization of ZIBs. Therefore, this work systematically introduces the research progress of zinc metal-free anodes in “rocking chair” ZIBs. Zinc metal-free anodes are mainly discussed in four categories: transition metal oxides,transition metal sulfides, MXene(two dimensional transition metal carbide) composites, and organic compounds, with discussions on their properties and zinc storage mechanisms. Finally, the outlook for the development of zinc metal-free anodes is proposed. This paper is expected to provide a reference for the further promotion of commercial rechargeable ZIBs.

Vanadium oxide nanospheres encapsulated in N-doped carbon nanofibers with morphology and defect dual-engineering toward advanced aqueous zinc-ion batteries

Vanadium-based electrodes are regarded as attractive cathode materials in aqueous zinc ion batteries(ZIBs)caused by their high capacity and unique layered structure.However,it is extremely challenging to acquire high electrochemical performance owing to the limited electronic conductivity,sluggish ion kinetics,and severe volume expansion during the insertion/extraction process of Zn^(2+).Herein,a series of V_(2)O_(3)nanospheres embedded N-doped carbon nanofiber structures with various V_(2)O_(3)spherical morphologies(solid,core-shell,hollow)have been designed for the first time by an electrospinning technique followed thermal treatments.The N-doped carbon nanofibers not only improve the electrical conductivity and the structural stability,but also provides encapsulating shells to prevent the vanadium dissolution and aggregation of V_(2)O_(3)particles.Furthermore,the varied morphological structures of V_(2)O_(3)with abundant oxygen vacancies can alleviate the volume change and increase the Zn^(2+)pathway.Besides,the phase transition between V_(2)O_(3)and Zn_XV_(2)O_(5-m)·n H_(2)O in the cycling was also certified.As a result,the as-obtained composite delivers excellent long-term cycle stability and enhanced rate performance for coin cells,which is also confirmed through density functional theory(DFT)calculations.Even assembled into flexible ZIBs,the sample still exhibits superior electrochemical performance,which may afford new design concept for flexible cathode materials of ZIBs.

Defect engineering of vanadium-based electrode materials for zinc ion battery

With the quick development of sustainable energy sources, aqueous zinc-ion batteries(AZIBs) have become a highly potential energy storage technology. It is a crucial step to construct desired electrode materials for improving the total performance of AZIBs. In recent years, considerable efforts have focused on the modification of vanadium-based cathode materials. In this review, we summarized defect engineering strategies of vanadium-based cathodes, including oxygen defects, cation vacancies and heterogeneous doping. Then, we discussed the effect of various defects on the electrochemical performance of electrode materials. Finally, we proposed the future challenges and development directions of V-based cathode materials.

Rational design of interfacial bonds within dual carbon-protected manganese oxide towards durable aqueous zinc ion battery

Manganese-based cathode materials are promising candidates for aqueous zinc ion batteries(AZIBs)by reason of their low cost and high energy density.However,their practical applicability is hampered by the intrinsic defects of poor electrical conductivity,sluggish reaction kinetics,and severe structural deterioration.Herein,we constructed a hierarchically porous structure composed of carbon-encapsulated Mn O nanoparticles(MOC)and three-dimensional(3D)nitrogen-doped graphene aerogel(NGA)(denoted as MOC@NGA).The hybrid was synthesized by a facile in-situ coprecipitation and annealing of manganesebased metal-organic framework(Mn-MOF74)and NGA composite(Mn-MOF74@NGA).Specifically,the carbon shells inherited from organic ligand of Mn-MOF74 could restrain the volume changes of Mn O,and the porous NGA prevented the agglomeration of MOC nanoparticles and enriched the types of interfacial chemical bonds.Profiting from the synergistic effect of rich interface chemical bonds and dual-carbon protection,the MOC@NGA hybrids exhibit fast interfacial electron/charge transfer and transport,and outstanding structural stability.Therefore,MOC@NGA cathode delivers an excellent rate performance(270 and 99.8 m Ah g^(-1)at 0.1 and 2.0 A g^(-1))and maintains an excellent specific capacity of 151.6 m Ah g^(-1)after 2,000cycles at 1.0 A g^(-1).Moreover,the fabricated MOC@NGA-based quasi-solid-state battery not only achieves outstanding flexibility but also displays impressive cycling stability,demonstrating a promising potential for portable and flexible equipment.This work provides a feasible strategy for the fabrication of the bridging structure of manganese-based oxides and porous carbon matrix for high-specific capacity and durable AZIBs cathodes.

Advances in the structure design of substrate materials for zinc anode of aqueous zinc ion batteries

Aqueous zinc ion batteries(AZIBs) demonstrate tremendous competitiveness and application prospects because of their abundant resources,low cost, high safety, and environmental friendliness. Although the advanced electrochemical energy storage systems based on zinc ion batteries have been greatly developed, many severe problems associated with Zn anode impede its practical application, such as the dendrite formation,hydrogen evolution, corrosion and passivation phenomenon. To address these drawbacks, electrolytes, separators, zinc alloys, interfacial modification and structural design of Zn anode have been employed at present by scientists. Among them, the structural design for zinc anode is relatively mature, which is generally believed to enhance the electroactive surface area of zinc anode, reduce local current density, and promote the uniform distribution of zinc ions on the surface of anode. In order to explore new research directions, it is crucial to systematically summarize the structural design of anode materials. Herein, this review focuses on the challenges in Zn anode, modification strategies and the three-dimensional(3D) structure design of substrate materials for Zn anode including carbon substrate materials, metal substrate materials and other substrate materials. Finally, future directions and perspectives about the Zn anode are presented for developing high-performance AZIBs.

Realizing Highly Reversible Zinc Anode via Controlled-current Pre-deposition

Aqueous zinc ion batteries have been considered as the prominent candidate in the next-generation batteries for its low cost,safety and high theoretical capacity.Nonetheless,formation of zinc dendrites and side reactions at the electrode/electrolyte interface during the zinc plating/stripping process affect the cycling reversibility of the zinc anode.Regulation of the zinc plating/stripping process and realizing a highly reversible zinc anode is a great challenge.Herein,we applied a simple and effective approach of controlled-current zinc pre-deposition at copper mesh.At the current density of 40 mA cm^(-2),where the electron/ion transfers are both continuous and balanced,the Zn@CM-40 electrode with the(002)crystal plane orientation and the compactly aligned platelet morphology was successfully obtained.Compared with the zinc foil,the Zn@CM-40 exhibits greatly enhanced reversibility in the repeated plating/stripping(850 h at 1 mA cm^(-2))for the symmetric battery test.A series of characterization techniques including electrochemical analyses,XRD,SEM and optical microscopy observation,were used to demonstrate the correlation between the structure of pre-deposited zinc layer and the cycling stability.The COSMOL Multiphysics modeling demonstrates a more uniform electric field distribution in the Zn@CM than the zinc foil due to the aligned platelet morphology.Furthermore,the significant improvement is also achieved in a Zn||MnO_(2)full battery with a high capacity-retention(87%vs 47.8%).This study demonstrates that controlled-current electrodeposition represents an important strategy to regulate the crystal plane orientation and the morphology of the pre-deposited zinc layer,hence leading to the highly reversible and dendrite-free zinc anode for high-performance zinc ion batteries.

Designing interstitial boron-doped tunnel-type vanadium dioxide cathode for enhancing zinc ion storage capability

Chemical doping is a powerful method to intrinsically tailor the electrochemical properties of electrode materials.Here,an interstitial boron-doped tunnel-type VO_(2)(B)is constructed via a facile hydrothermal method.Various analysis techniques demonstrate that boron resides in the interstitial site of VO_(2)(B)and such interstitial doping can boost the zinc storage kinetics and structural stability of VO_(2)(B)cathode during cycling.Interestingly,we found that the boron doping level has a saturation limit peculiarity as proved by the quantitative analysis.Notably,the 2 at.%boron-doped VO_(2)(B)shows enhanced zinc ion storage performance with a high storage capacity of 281.7 mAh g^(-1) at 0.1 A g^(-1),excellent rate performance of 142.2 mAh g^(-1) at 20 A g^(-1),and long cycle stability up to 1000 cycles with the capacity retention of 133.3 mAh g^(-1) at 5 A g^(-1).Additionally,the successful preparation of the boron-doped tunneltype α-MnO_(2) further indicates that the interstitial boron doping approach is a general strategy,which supplies a new chance to design other types of functional electrode materials for multivalence batteries.

Graphdiyne Hybrid Nanowall Arrays for High-capacity Aqueous Rechargeable Zinc Ion Battery

Development of aqueous rechargeable zinc ion battery is an important direction towards grid energy storage sought in various applications.At present,the efficient utilization of aqueous rechargeable zinc ion batteries has been seriously affected due to the defects nature of the cathode materials,such as poor capacity,limited rate performance,and limited cycle stability.Therefore,the search for high-performance cathode materials is a main challenge in this field.Herein,we in-situ prepared graphdiyne-wrapped K_(0.25)·MnO_(2)(K_(0.25)·MnO_(2)@GDY)hybrid nanowall arrays as the cathode of aqueous rechargeable zinc ion battery.The hybridnanowall arrays have obviously alleviated the pulverization and sluggish kinetic process of MnO_(2) cathode materials and shown high specific capacity(520 mA·h/g at a current density of 55 mA/g),which is near-full two-electron capacity.The high specific capacity was resulted from more than one Zn^(2+)(de)intercalation process occurring per formula unit,in which we observed a structural evolution that partially stemmed from ion exchange between the intercalated K^(+) and Zn^(2+) ions during the discharge process.The present investigation not only provides a new material for the aqueous rechargeable Zn ion batteries,also contributes a novel route for the development of next generation aqueous rechargeable Zn ion batteries with high capacity.

Defect engineering in Co-doped Ni_(3)S_(2) nanosheets as cathode for high-performance aqueous zinc ion battery

With the merits of low cost,environmental benignity,and high safety,aqueous zinc ion batteries(AZIBs)have great potential in the field of energy storage.In this paper,we craft a Co-doped Ni3 S2 with abundant sulfur vacancies as effective cathode materials(Co-Ni_(3) S_(2-x)) for AZIBs by hydrothermal and chemical reduction method.Notably,cobalt doping and abundant sulfur vacancies can effectively increase the conductivity and the number of active sites for electrochemical reactions,which gives the Co-Ni_(3) S_(2-x) electrode the outstanding capability to energy storage.By coupling Co-Ni_(3) S_(2-x) cathode with Zn anodes to assemble alkaline AZIBs,the Co-Ni_(3) S_(2-x)//Zn full battery exhibits excellent specific capacity(183.9 mAh g^(-1) at 1 A g^(-1),based on cathode mass) and extraordinary cycling durability(72.9% capacity retention after 6000 cycles).First-principles calculations based on density functional theory(DFT) confirm that the Co-Ni_(3) S_(2-x) electrode has strong energy storage capacity and electrochemical stability.The results provide an extremely significant reference in designs of self-supported bimetallic sulfide nanosheets,which have promising applications in high-performance energy storage devices.

Recent advances in interfacial modification of zinc anode for aqueous rechargeable zinc ion batteries

To tackle energy crisis and achieve sustainable development, aqueous rechargeable zinc ion batteries have gained widespread attention in large-scale energy storage for their low cost, high safety, high theoretical capacity, and environmental compatibility in recent years. However, zinc anode in aqueous zinc ion batteries is still facing several challenges such as dendrite growth and side reactions(e.g., hydrogen evolution), which cause poor reversibility and the failure of batteries. To address these issues, interfacial modification of Zn anodes has received great attention by tuning the interaction between the anode and the electrolyte. Herein, we present recent advances in the interfacial modification of zinc anode in this review. Besides, the challenges of reported approaches of interfacial modification are also discussed.Finally, we provide an outlook for the exploration of novel zinc anode for aqueous zinc ion batteries.We hope that this review will be helpful in designing and fabricating dendrite-free and hydrogenevolution-free Zn anodes and promoting the practical application of aqueous rechargeable zinc ion batteries.

Constructing an ion‐oriented channel on a zinc electrode through surface engineering

The inherent shortcomings of a zinc anode in aqueous zinc‐ion batteries(ZIBs)such as zinc dendrites and side reactions severely limit their practical application.Herein,to address these issues,an ion‐oriented transport channel constructed by graphdiyne(GDY)nanowalls is designed and grown in situ on the surface of a zinc electrode.The vertically stacked GDY nanowalls with a unique hierarchical porous structure and mechanical properties form a nanomesh‐like interface on the zinc electrode,acting as an ion‐oriented channel,which can efficiently confine the segmented growth of zinc metal in microscopic regions of hundreds of nanometers.In those microscopic regions,the uniform domain current density is effortlessly maintained compared with a large surface area,thereby inhibiting zinc dendrites effectively.Besides,due to the presence of the ion‐oriented channel,the modified zinc anode demonstrates long‐term stable zinc plating/stripping performance for more than 600 h at 1 mAh cm^(−2)in an aqueous electrolyte.In addition,full‐cells coupled with MnO2 show high specific capacity and power density,as well as excellent cycling stability with a capacity retention of 82%after 5000 cycles at 1 A g^(−1).This work provides a feasible and accessible surface engineering approach to modify the electrode interface for confined and dendrite‐free zinc deposition in aqueous ZIBs.