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...     

A carbonyl-rich covalent organic framework as a high-performance cathode material for aqueous rechargeable zinc-ion batteries

Aqueous rechargeable zinc-ion batteries (ZIBs) provide high theoretical capacity, operational safety, low-cost and environmental friendliness for large-scale energy storage and wearable electronic devices, but their future development is plagued by low capacity and poor cycle life due to the lack of suitable cathode materials. In this work, a covalent organic framework (Tp-PTO-COF) with multiple carbonyl active sites is synthesized and successfully introduced in aqueous rechargeable ZIBs for the first time. Tp-PTO-COF delivers high specific capacities of 301.4 and 192.8 mA h g⁻¹ at current densities of 0.2 and 5 A g⁻¹, respectively, along with long-term durability and flat charge–discharge plateaus. The remarkable electrochemical performance is attributed to the abundance of nucleophilic carbonyl active sites, well defined porous structure and inherent chemical stability of Tp-PTO-COF. Moreover, the structural evolution and Zn²⁺ ion intercalation mechanism are discussed and revealed by the experimental analysis and density functional theory calculations. These results highlight a new avenue to develop organic cathode materials for high performance and sustainable aqueous rechargeable ZIBs.

A covalent organic framework (Tp-PTO-COF) with carbonyl active sites was proposed as a novel cathode material and successfully applied in aqueous rechargeable zinc-ion batteries (ZIBs).     

Electrospun V2O5 nanostructures with controllable morphology as high-performance cathode materials for lithium-ion batteries

Porous V(2)O(5) nanotubes, hierarchical V(2)O(5) nanofibers, and single-crystalline V(2)O(5) nanobelts were controllably synthesized by using a simple electrospinning technique and subsequent annealing. The mechanism for the formation of these controllable structures was investigated. When tested as the cathode materials in lithium-ion batteries (LIBs), the as-formed V(2)O(5) nanostructures exhibited a highly reversible capacity, excellent cycling performance, and good rate capacity. In particular, the porous V(2)O(5) nanotubes provided short distances for Li(+)-ion diffusion and large electrode-electrolyte contact areas for high Li(+)-ion flux across the interface; Moreover, these nanotubes delivered a high power density of 40.2?kW?kg(-1) whilst the energy density remained as high as 201?W?h?kg(-1), which, as one of the highest values measured on V(2)O(5)-based cathode materials, could bridge the performance gap between batteries and supercapacitors. Moreover, to the best of our knowledge, this is the first preparation of single-crystalline V(2)O(5) nanobelts by using electrospinning techniques. Interestingly, the beneficial crystal orientation provided improved cycling stability for lithium intercalation. These results demonstrate that further improvement or optimization of electrochemical performance in transition-metal-oxide-based electrode materials could be realized by the design of 1D nanostructures with unique morphologies.     

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.     

High-performance Na1.25V3O8 nanosheets for aqueous zinc-ion battery by electrochemical induced de-sodium at high voltage

Aqueous rechargeable zinc-ion batteries (ARZIBs) are expected to replace organic electrolyte batteries owing to its low price, safe and environmentally friendly characteristics. Herein, we fabricated vanadium-based Na_1.25V₃O₈ nanosheets as a cathode material for ARZIBs, which present a high performance by electrochemical de-sodium at high voltage to form Na₂V₆O₁₆ phase in the first cycle: high capacity of 390 mAh/g at 0.1 A/g, high rate performance (162 mAh/g at 10 A/g) and superior cycle stability (179 mAh/g with a high capacity retention of 88.2% of the maximum capacity after 2000 cycles). In addition, the cell exhibits a high energy density of 416.9 Wh/kg at 143.6 W/kg, suggesting great potential of the as-prepared Na_1.25V₃O₈ nanosheets for ARZIBs     

Free-standing vanadium pentoxide nanoribbon film as a high-performance cathode for rechargeable sodium batteries

Vanadium pentoxide(V_2O_5·nH_2O) nanoribbons are synthesized via a hydrothermal process. These ribbons are 20 nm thick, 200 nm to 1 μm wide and several tens of micrometers long. Free-standing binder-free films are prepared by using these nanoribbons with multi-walled carbon nanotubes(MWCNTs) and used as the cathode for rechargeable sodium batteries. The large interlayer space between the V_2O_5 bilayers can enhance the kinetics of sodium ion intercalation/deintercalation. In addition, the intertwining network of the V_2O_5·0.34 H_2O film provides efficient electron conduction pathways and shortens diffusion distances of sodium ion. The electrochemical tests prove that the freestanding V_2O_5 · 0.34 H_2O film cathode delivers high reversible specific capacities(190 mAh/g) and good cycling stabilities(170 mAh/g after 150 cycles) in the voltage range between 1.5 V and 3.5 V.     

Template-free solvothermal synthesis of yolk-shell V2O5 microspheres as cathode materials for Li-ion batteries

Uniform yolk-shell V(2)O(5) microspheres were synthesized via a facile template-free solvothermal route and subsequent calcination treatment in air. The resulting cathode materials showed a high specific capacity of 220 mA h g(-1) after 30 cycles and good rate capability.     

Porous V2O5-SnO2/CNTs composites as high performance cathode materials for lithium-ion batteries

Vanadium pentoxide (V₂O₅) exhibits high theoretical capacities when used as a cathode in lithium ion batteries (LIBs), but its application is limited by its structural instability as well as its low lithium and electronic conductivities. A porous composite of V₂O₅-SnO₂/carbon nanotubes (CNTs) was prepared by a hydrothermal method and followed by thermal treatment. The small particles of V₂O₅, their porous structure and the coexistence of SnO₂ and CNTs can all facilitate the diffusion rates of the electrons and lithium ions. Electrochemical impedance spectra indicated higher ionic and electric conductivities, as compared to commercial V₂O₅. The V₂O₅-SnO₂/CNTs composite gave a reversible discharge capacity of 198 mAh·g^?1 at the voltage range of 2.05–4.0 V, measured at a current rate of 200 mA·g^?1, while that of the commercial V₂O₅ was only 88 mAh·g^?1, demonstrating that the porous V₂O₅-SnO₂/CNTs composite is a promising candidate for high-performance lithium secondary batteries.     

Anti-aggregation growth and hierarchical porous carbon encapsulation enables the C@VO2 cathode with superior storage capability for aqueous zinc-ion batteries

Self-aggregation and sluggish transport kinetics of cathode materials would usually lead to the poor electrochemical performance for aqueous zinc-ion batteries (AZIBs).In this work,we report the construction of C@VO₂composite via anti-aggregation growth and hierarchical porous carbon encapsulation.Both of the morphology of composite and pore structure of carbon layer can be regulated by tuning the adding amount of glucose.When acting as cathode applied for AZIBs,the C@VO₂-3...     

The mechanical hybrid of V2O5 microspheres/graphene as an excellent cathode for lithium-ion batteries

Journal of Solid State Electrochemistry - Currently, lithium-ion batteries are widely used in many areas, but they are still limited by the lower cycle stability and energy density. The development...     

Engineering of yolk-shelled FeSe2@nitrogen-doped carbon as advanced cathode for potassium-ion batteries

Potassium-ion batteries (KIBs) have become the most promising alternative to lithium-ion batteries for large-scale energy storage system due to their abundance and low cost. However, previous reports focused on the intercalation-type cathode materials usually showed an inferior capacity, together with a poor cyclic life caused by the repetitive intercalation of large-size K-ions, which hinders their practical application. Here, we combine the strategies of carbon coating, template etching and hydrothermal selenization to prepare yolk-shelled FeSe₂@N-doped carbon nanoboxes (FeSe₂@C NBs), where the inner highly-crystalline FeSe₂ clusters are completely surrounded by the self-supported carbon shell. The integrated and highly conductive carbon shell not only provides a fast electron/ion diffusion channel, but also prevents the agglomeration of FeSe₂ clusters. When evaluated as a conversion-type cathode material for KIBs, the FeSe₂@C NBs electrode delivers a relatively high specific capacity of 257 mAh/g at 100 mA/g and potential platform of about 1.6 V, which endow a high energy density of about 411 Wh/kg. Most importantly, by designing a robust host with large internal void space to accommodate the volumetric variation of the inner FeSe₂ clusters, the battery based on FeSe₂@C NBs exhibits ultra-long cycle stability. Specifically, even after 700 cycles at 100 mA/g, a capacity of 221 mAh/g along with an average fading rate of only 0.02% can be retained, which achieves the optimal balance of high specific capacity and long-cycle stability.     

MOF-derived ZnCo2O4/C wrapped on carbon fiber as anode materials for structural lithium-ion batteries

In this work, large area MOF-derived ZnCo₂O₄/C anchored on carbon fiber as high-performance anode materials was fabricated via a facile method and subsequent annealing treatment.     

Low-coordination water Prussian white as cathode for high-performance potassium-ion batteries

Prussian whites(PWs) with a three-dimensional framework can accommodate the insertion and extraction of ions with large radius,which have been widely used in potassium ion batteries.However,PWs show the poor cycling performance and inferior rate ability because of high coordinated water.In this work,PWs with different water content were synthesized via a coprecipitation method by controlling the reaction temperature.The sample with low-coordination water prohibits the best electrochemical performance.It shows a high capacity of 120.5 mAh/g at 100 mA/g for potassium-ion batteries(KIBs).It also exhibits a good rate performance,displaying a capacity of 73.2 mAh/g at 500 mA/g.     

准固态锂离子电池正极材料柱[5]醌的研究

锂离子电池的有机正极材料由于具有比容量高、环境友好和廉价等优点,近年来成为研究的热点.但是,有机电极材料在液态电解液中的溶解流失易导致其容量迅速衰减,严重限制了它们的实际应用.本工作基于聚(甲基丙烯酸酯)/聚乙二醇的准固态电解质,考察了以柱[5]醌为正极的准固态锂二次电池的电化学性能.结果显示,柱[5]醌正极不仅保持了高容量的特性(首次放电容量410 mA h/g),并且循环寿命得到了有效提高.0.2 C下循环100周后,电极的容量保持率为88.5%,显示了柱[5]醌在高比能量准固态锂离子电池中的应用潜力.     

V2O5@TiO2 composite as cathode material for lithium-ion storage with excellent performance

Journal of Solid State Electrochemistry - V2O5 is a promising candidate for cathode active material for Li-ion batteries due to its high theoretical specific capacity but suffers from poor rate...     

V2O5-Ag2O/η-Al2O3催化剂上甲苯氧化制苯甲醛的研究

制备了一系列负载型V—Ag—Al—O催化剂并用于甲苯的气相选择氧化制苯甲醛反应，考察了催化剂组成对反应性能的影响．研究发现，V205负载量为12．5％、Ag2O负载量为7．5％并经773K活化的4号催化剂，在空速467．6h-1，温度663K时反应，得到了甲苯转化率49．58％、苯甲醛选择性29．22％的较好结果．用XRD、XPS、SEM等测试手段，对催化剂进行了结构表征．     

LiMn2O4 nanorods as a super-fast cathode material for aqueous rechargeable lithium batteries

LiMn₂O₄ nanorods were prepared by a facile hydrothermal method in combination with traditional solid-state reactions and characterized by X-ray diffraction analysis. Their electrochemical behavior was tested by cyclic voltammetry and repeated charge/discharge cycling. Results show that the reversible intercalation/deintercalation of Li-ions into/from LiMn₂O₄ cathode can yield up to 110 mAh/g at 4.5 C, and still retains 88% at the very large charge rate of 90 C with well-defined charge and discharge plateaus. It presents very high power density, up to 14.5 kW/kg, and very excellent cycling behavior, 94% capacity retention after 1200 cycles. It is thus a competitor for LiFePO₄.