3D porous V_2O_5 architectures for high-rate lithium storage

The discovery of novel electrode materials promises to unleash a number of technological advances in lithium-ion batteries. V_2O_5 is recognized as a high-performance cathode that capitalizes on the rich redox chemistry of vanadium to store lithium. To unlock the full potential of V_2O_5, nanotechnology solution and rational electrode design are used to imbue V_2O_5 with high energy and power density by addressing some of their intrinsic disadvantages in macroscopic crystal form. Here, we demonstrate a facile and environmental-friendly method to prepare nanorods-constructed 3D porous V_2O_5 architectures(3 D-V_2O_5)in large-scale. The 3D porous architecture is found to be responsible for the enhanced charge transfer kinetics and Li-ion diffusion rate of the 3D-V_2O_5 electrode. As the result, the 3D-V_2O_5 surpasses the conventional bulk V_2O_5 by showing enhanced discharge capacity and rate capability(delivering 154 and127 m Ah g~(-1) at 15 and 20 C, respectively).     

Cascading V2O3/N-doped carbon hybrid nanosheets as high-performance cathode materials for aqueous zinc-ion batteries

In recent years, especially when there is increasing concern about the safety issue of lithium-ion batteries（LIBs）, aqueous Zn-ion batteries（ZIBs） have been getting a lot of attention because of their costeffectiveness, materials abundance, high safety, and ecological friendliness. Their working voltage and specific capacity are mainly determined by their cathode materials. Vanadium oxides are promising cathode materials for aqueous ZIBs owing to their low cost, abundant resources, and multivale...     

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 K0.25·MnO2(K0.25·MnO2@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 MnO2 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 Zn2+(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 Zn2+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.     

Electrochemical and structural evolution of structured V_2O_5 microspheres during Li-ion intercalation

With the development of stable alkali metal anodes,V₂O₅ is gaining traction as a cathode material due to its high theoretical capacity and the ability to intercalate Li,Na and K ions.Herein,we report a method for synthesizing structured orthorhombic V₂O₅ microspheres and investigate Li intercalation/deintercalation into this material.For industry adoption,the electrochemical behavior of V₂O₅ as well as structural and phase transformation attributing to Li intercalation reaction must be further investigated.Our synthesized V₂O₅ microspheres consisted of small primary particles that were strongly joined together and exhibited good cycle stability and rate capability,triggered by reversible volume change and rapid Li ion diffusion.In addition,the reversibility of phase transformation(a,e,d,c and xLixV₂O₅)and valence state evolution(5+,4+,and 3.5+)during intercalation/de-intercalation were studied via in-situ X-ray powder diffraction and X-ray absorption near edge structure analyses.     

层状钒青铜纳米片的制备及其锂离子电池阳极材料性能

室温下, 在水溶液中将铵根离子和水分子插入到商用V₂O₅纳米颗粒的层间, 制得了层状的钒青 铜[(NH₄)₂V₆O₁₆·H₂O]纳米片. 该纳米片的尺寸为2~10 μm, 厚度为50~250 nm. 与商用V₂O₅纳米颗粒相比, (NH₄)₂V₆O₁₆·H₂O纳米片用作锂离子电池(LIBs)的阳极材料时, 其性能得到较大提升, 包括大的可逆放电容量 (0.1 A/g时为1148 mA·h/g)、 出色的循环性能(循环70圈后在0.1 A/g时具有1002 mA·h/g的高容量)和高倍率性能(在0.1 A/g时具有1070 mA·h/g的可逆性能). 研究结果表明, (NH₄)₂V₆O₁₆·H₂O纳米片可以作为锂离子电池优良的阳极材料, 也有望应用于其它(如钠离子电池和锌离子电池等)可再充电电池.     

Recent advances of vanadium-based cathode materials for zinc-ion batteries

Zn-ion batteries (ZIBs) have gained great attention as promising next-generation power sources, because of their low cost, enviable safety and high theoretical capacity. Recently, massive researches have been devoted to vanadium-based materials as cathodes in ZIBs, owing to their multiple valence states, competitive gravimetric energy density, but the capacity degradation, sluggish kinetics, low operating voltage hinder further optimization of their performance in ZIBs. This review summarizes recent progress to increase the interlayer spacing, structural stability, and the diffusion ability of the guest Zn ions, including the insertion of different ions, introduction of defects, design of diverse morphologies, the combination of other materials. We also focus on approaches to promoting the valuable performance of vanadium-based cathodes, along with the related ongoing scientific challenges and limitations. Finally, the future perspectives and research directions of vanadium-based aqueous ZIBs are provided.     

Porous nanostructured ZnCo_2O_4 derived from MOF-74:High-performance anode materials for lithium ion batteries

Nanostructured metal oxides derived from metal organic frameworks have been shown to be promising materials for application in high energy density lithium ion batteries. In this work, porous nanostructured ZnCo_2O_4 and Co_3O_4 were synthesized by a facile and cost-effective approach via the calcination of MOF-74 precursors and tested as anode materials for lithium ion batteries. Compared with Co_3O_4, the electrochemical properties of the obtained porous nanostructured ZnCo_2O_4 exhibit higher specific capacity, more excellent cycling stability and better rate capability. It demonstrates a reversible capacity of 1243.2 m Ah/g after 80 cycles at 100 m A/g and an excellent rate performance with high average discharge specific capacities of 1586.8, 994.6, 759.6 and 509.2 m Ah/g at 200, 400, 600 and 800 m A/g, respectively.The satisfactory electrochemical performances suggest that this porous nanostructured ZnCo_2O_4 is potentially promising for application as an efficient anode material for lithium ion batteries.     

电解液调控策略提升水系锌离子电池正极材料电化学性能

水系锌离子电池(ZIBs)因安全性高、成本低、环境友好,以及负极锌高的理论容量(820 mAh·g^-1)和低的氧化还原电位(-0.76 V vs.SHE)等优点而受到研究者们的广泛关注,有望应用于大规模储能领域,但循环寿命仍是限制其规模化应用的瓶颈之一。通过电解液优化调控策略,可有效抑制正极材料的溶解、结构坍塌和界面副反应等问题,从而提高水系ZIBs的电化学性能。本文综述了电解液调控策略提升水系ZIBs正极材料电化学性能的研究进展,讨论了该策略所解决的具体问题和局限性,并对电解液体系的发展方向进行了展望。     

A High Performing Zn-Ion Battery Cathode Enabled by In Situ Transformation of V2O5 Atomic Layers

Developing high capacity and stable cathodes is a key to successful commercialization of aqueous Zn-ion batteries (ZIBs). Pure layered V₂O₅ has a high theoretical capacity (585 mAh g⁻¹), but it suffers severe capacity decay. Pre-inserting cations into V₂O₅ can substantially stabilize the performance, but at an expense of lowered capacity. Here we show that an atomic layer deposition derived V₂O₅ can be an excellent ZIB cathode with high capacity and exceptional cycle stability at once. We report a rapid in situ on-site transformation of V₂O₅ atomic layers into Zn₃V₂O₇(OH)₂⋅2 H₂O (ZVO) nanoflake clusters, also a known Zn-ion and proton intercalatable material. High concentration of reactive sites, strong bonding to the conductive substrate, nanosized thickness and binder-free composition facilitate ionic transport and promote the best utilization of the active material. We also provide new insights into the V₂O₅-dissolution mechanisms for different Zn-salt aqueous electrolytes and their implications to the cycle stability.     

Hewettite ZnV6O16 ⋅ 8H2O with Remarkably Stable Layers and Ultralarge Interlayer Spacing for High-Performance Aqueous Zn-Ion Batteries

Aqueous Zn-ion batteries (ZIBs) are promising candidates for grid-scale energy storage because of their intrinsic safety, low-cost and high energy-intensity. Vanadium-based materials are widely used as the cathode of ZIBs, especially A₂V₆O₁₆ ⋅ nH₂O (AVO, A=NH₄⁺, Na, K). However, AVO suffers from serious dissolution, phase transformation and narrow gallery spacing (∼3 Å), leading to poor cycling stability and rate capability. Herein, we unveiled the root cause of the performance degradation in the AVO cathode and therefore developed a new high-performance cathode of ZnV₆O₁₆ ⋅ 8H₂O (ZVO) for ZIB. Through a method of ion exchange induced phase transformation, AVO was converted to hewettite ZVO with larger gallery spacing (∼6 Å) and more stable V₆O₁₆ layers. ZVO cathode thus constructed delivers a high capacity of 365 and 170 mAh g⁻¹ at 0.5 and 15 A g⁻¹, while 86 % and 70 % of its capacity are retained at 0.5 A g⁻¹ after 300 cycles and at 15 A g⁻¹ after 10000 cycles, substantially better than conventional AVO.     

Facile preparation of core-shell Si@Li_4Ti_5O_(12) nanocomposite as large-capacity lithium-ion battery anode

As a promising alternative anode material,silicon(Si)presents a larger capacity than the commercial anode to achieve large capacity lithium-ion batteries.However,the application of pure Si as anode is hampered by limitations such as volume expansion,low conductivity and unstable solid electrolyte interphase.To break through these limitations,the core-shell Si@Li_4Ti_5O_(12)nanocomposite,which was prepared via in-situ self-assembly reaction and decompressive boiling fast concentration method,was proposed in this work.This anode combines the advantages of nano-sized Si particle and pure Li_4Ti_5O_(12)(LTO)coating layer,improving the performance of the lithium-ion batteries.The Si@Li_4Ti_5O_(12)anode displays a high initial discharge/charge specific capacity of 1756/1383 m Ah g~(-1)at 500 m A g~(-1)(representing high initial coulombic efficiency of 78.8%),a large rate capability(specific capacity of 620 m Ah g~(-1)at4000 m A g~(-1)),an outstanding cycling stability(reversible specific capacity of 883 m Ah g~(-1)after 150 cycles)and a low volume expansion rate(only 3.3%after 150 cycles).Moreover,the synthesis process shows the merits of efficiency,simplicity,and economy,providing a reliable method to fabricate large capacity Si@Li_4Ti_5O_(12)nanocomposite anode materials for practical lithium-ion batteries.     

Manganese-based cathode materials for aqueous rechargeable zinc-ion batteries: recent advance and future prospects

Zinc-ion batteries (ZIBs), which use mild aqueous electrolyte, have attracted increasing attention, due to their unique advantages such as low cost, high safety, environmental friendliness, and ease of manufacture. At present, developing a kind of cathode materials with stable structures and large capacities for ZIBs is a hot research topic. Among all ZIBs cathode materials, manganese-based cathode materials have the advantages of low cost, abundant reserves, low toxicity, rich valence states, and high zinc storage capacity, which make them one of the most promising candidates. In recent years, manganese-based composites with different crystal structures have been extensively studied as cathode materials of ZIBs. In this paper, the reaction mechanism of ZIBs cathodes is discussed in detail, and the challenges faced by manganese-based cathode materials and the latest research progress are examined deeply. In addition, a number of optimization strategies aimed at improving the electrochemical performance of the cathode of ZIBs are outlined. Finally, the future prospect of ZIBs is presented.     

Vanadium-based cathodes for aqueous zinc ion batteries: Structure,mechanism and prospects

As an emerging energy storage device with high-safety aqueous electrolytes, low-cost, environmental benignity and large-reserves, the rechargeable aqueous zinc-ion batteries(AZIBs) have attracted more and more attention. Vanadium-based compounds are also supposed as the potential candidate cathode materials for AZIBs due to their wide variety of phases, variable crystal structures and high theoretical capacity. In this review, the recent progress in the development of vanadium-based materials wa...     

Tuning the layer structure of molybdenum trioxide towards high-performance aqueous zinc-ion batteries

Aqueous zinc-ion batteries (ZIBs) have attracted significant attentions because of low cost and high reliability. However, conventional ZIBs are severely limited by the development of high energy density cathode materials with reversible Zn²⁺ insertion/extraction. Herein, a conducting polymer intercalated MoO₃ (PMO) with extensively extended interlayer spacing is developed as a high-performance ZIBs cathode material. The interlayer spacing of PMO is prominently increased which results in an improved Zn²⁺ mobility during charge and discharge process. More significantly, the electrochemical results reveals that the intercalation of PANI facilitates the charge storage and reinforces the layered structure of MoO₃, leading to a high capacity and good cycling stability. DFT calculation further reveals the intercalation of PANI into MoO₃ significantly lower Zn²⁺ diffusion barrier. Benefit from these advantages, the ZIBs based on PMO electrode delivers a considerable capacity of 157 mAh/g at 0.5 A/g and ameliorative stability with 63.4% capacity retention after 1000 cycles.     

V-MOF@graphene derived two-dimensional hierarchical V2O5@graphene as high-performance cathode for aqueous zinc-ion batteries

Rechargeable aqueous zinc-ion batteries (ZIBs) are attracting growing attention in the field of grid-scale energy storage systems due to their reliable safety and low cost. However, it is still hindered by the limited choices of suitable cathode materials with high performance for aqueous ZIBs. Herein, we developed a V-MOF@graphene derived two-dimensional hierarchical V₂O₅@graphene for the first time, where the porous V₂O₅ nanosheets are homogeneously attached to the 2D graphene substrate. Benefiting from the unique 2D composite structure with excellent electronic and ionic conductivity, adequate active sites, as well as the synergistic effect between the ultrathin V₂O₅ nanosheets and graphene, the V₂O₅@graphene here exhibits outstanding electrochemical performance in aqueous ZIBs. Particularly, it delivered an ultrahigh reversible capacity of 378 mAh/g at a current density of 2 A/g. What is more, a high specific capacity of 305 mAh/g after 100 cycles at 0.1 A/g and 200 mAh/g after 1,000 cycles at 1 A/g can be achieved. These ideal results suggest that the V₂O₅@graphene cathode hold great promise for high-performance aqueous zinc-ion batteries.     

A redox-active conjugated microporous polymer cathode for highperformance lithium/potassium-organic batteries

Organic redox-active materials have emerged as a class of electrode materials for rechargeable batteries due to their high redox activity,low cost,structure diversity and flexibility.However,the high solubility of organic small molecules in organic electrolytes commonly leads to the fast capacity decay with cycling.Herein,we report a redox-active conjugated microporous polymer of poly(pyrene-co-anthraquinone)(Py Aq)cathode material consisting of pyrene and anthraquinone units.Benefiting from the highly cross-linked polymer structure with insoluble nature in organic electrolytes,the high surface area and the plentiful redox-active carbonyl groups,the Py Aq cathode demonstrates outstanding electrochemical performances for both lithium-ion batteries(LIBs)and potassium-ion batteries(KIBs).Specifically,the Py Aq cathode for LIBs delivers a high reversible capacity of 169 m Ah g^-1 at the current density of 20 m A g^-1,a high rate capability(142 m Ah g^-1 at 1000 m A g^-1)and an excellent cycling stability for 4000 cycles.Additionally,the Py Aq cathode for KIBs also exhibits a high reversible capacity of143 m Ah g^-1 with a long cycling life over 800 cycles.The excellent electrochemical performance demonstrates that the newly developed Py Aq could be an attractive cathode material for the advanced energy storage technologies.     

Proton Insertion Chemistry of a Zinc–Organic Battery

Proton storage in rechargeable aqueous zinc‐ion batteries (ZIBs) is attracting extensive attention owing to the fast kinetics of H⁺ insertion/extraction. However, it has not been achieved in organic materials‐based ZIBs with a mild electrolyte. Now, aqueous ZIBs based on diquinoxalino [2,3‐a:2′,3′‐c] phenazine (HATN) in a mild electrolyte are developed. Electrochemical and structural analysis confirm for the first time that such Zn–HATN batteries experience a H⁺ uptake/removal behavior with highly reversible structural evolution of HATN. The H⁺ uptake/removal endows the Zn–HATN batteries with enhanced electrochemical performance. Proton insertion chemistry will broaden the horizons of aqueous Zn–organic batteries and open up new opportunities to construct high‐performance ZIBs.     

Highly Stable Aqueous Zinc‐Ion Storage Using a Layered Calcium Vanadium Oxide Bronze Cathode

Cost‐effective aqueous rechargeable batteries are attractive alternatives to non‐aqueous cells for stationary grid energy storage. Among different aqueous cells, zinc‐ion batteries (ZIBs), based on Zn²⁺ intercalation chemistry, stand out as they can employ high‐capacity Zn metal as the anode material. Herein, we report a layered calcium vanadium oxide bronze as the cathode material for aqueous Zn batteries. For the storage of the Zn²⁺ ions in the aqueous electrolyte, we demonstrate that the calcium‐based bronze structure can deliver a high capacity of 340 mA h g^?1 at 0.2 C, good rate capability, and very long cycling life (96 % retention after 3000 cycles at 80 C). Further, we investigate the Zn²⁺ storage mechanism, and the corresponding electrochemical kinetics in this bronze cathode. Finally, we show that our Zn cell delivers an energy density of 267 W h kg^?1 at a power density of 53.4 W kg^?1.     

High Rate Performance of Aqueous Magnesium-iron-ion Batteries Based on Fe_2O_3@GH as the Anode

Aqueous Mg-ion batteries (MIBs) are safe,non-toxic and low-cost.Magnesium has a high theoretical specific capacity with its ion radius close to that of lithium.Therefore,aqueous magnesium ion batteries have great research advantages in green energy.To acquire the best electrode materials for aqueous magnesium ion batteries,it is necessary for the structural design in material.Fe_2O_3 is an anode material commonly used in Li-ion battery.However,the nano-cube Fe_2O_3 combined with graphene hydrogels (GH) can be successfully prepared and employed as an anode,which is seldom researched in the aqueous batteries system.The Fe_2O_3/GH is used as anode in the dual Mg SO_4+Fe SO_4 aqueous electrolyte,avoiding the irreversible deintercalation of magnesium ions.In addition,the Fe element in anode material can form the Fe~(3+)/Fe~(2+)and Fe~(2+)/Fe~(3+)redox pairs in the Mg SO_4+Fe SO_4 electrolyte.Thus,the reversible insertion/(de)insertion of magnesium and iron ions into/from the host anode material can be simultaneously achieved.After the initial charge,the anodic structure is changed to be more stable,avoiding the formation of Mg O.The Fe_2O_3/GH demonstrates high rate properties and reversible capacities of 198,151,121,80,75 and 27 m Ah g~(-1) at 50,100,200,300,500 and1000 m A g~(-1) correspondingly.     

锌离子在水相介质Zn/V_2O_5二次电池中的迁移性能研究

利用间歇性恒电流测定法和Ｘ Ｒａｙ衍射法,研究水相介质的Ｚｎ／Ｖ２Ｏ５二次电池中的锌离子在正极材料中的迁移性能及其放电机理;讨论锌离子在正极材料中发生迁移时的某些动力学参数与放电深度的关系．实验结果表明,该电池的正极放电反应为锌离子在ＺｎｘＶ２Ｏ５中的嵌入过程．