In Situ Electrochemical Transformation Reaction of Ammonium-Anchored Heptavanadate Cathode for Long-Life Aqueous Zinc-Ion Batteries

Ion-Molecule Co-Confining Ammonium Vanadate Cathode for High-Performance Aqueous Zinc-Ion Batteries

Vanadium-based cathode materials have attracted great attention in aqueous zinc-ion batteries (AZIBs). However, the inferior ion transport and cyclic stability due to the strong Coulomb interaction between Zn2+ and the lattice limit their further application. In this work, CO2 molecules are in situ embedded in the interlayer structure of NH4V4O10 by decomposing excess H2C2O4·2H2O in the main framework, obtaining an ion-molecule co-confining NH4V4O10 for AZIB cathode material. The introduced CO2 molecules expanded the interlayer spacing of NH4V4O10, broadened the diffusion channel of Zn2+, and stabilized the structure of NH4V4O10 as the interlayer pillars together withNH 4 + ${\mathrm{NH}}_4^ + $ , which effectively improved the Zn2+ diffusion kinetics and cycle stability of the electrode. In addition, the binding betweenNH 4 + ${\mathrm{NH}}_4^ + $ and the host framework is stabilized via hydrogen bonds with CO2 molecules. NVO-CO2-0.8 exhibited excellent specific capacity (451.1 mAh g-1 at 2 A g-1), cycle stability (214.0 mAh g-1 at 10 A g-1 after 1000 cycles) and rate performance. This work provides new ideas and approaches for optimizing vanadium-based materials with high-performance AZIBs.

Vanadium-Based Cathodic Materials of Aqueous Zn-Ion Battery for Superior-Performance with Prolonged-Life Cycle

Aqueous Zn-ion battery systems (AZIBs) have emerged as the most dependable solution, as demonstrated by successful systematic growth over the past few years. Cost effectivity, high performance and power density with prolonged life cycle are some major reason of the recent progress in AZIBs. Development of vanadium-based cathodic materials for AZIBs has appeared widely. This review contains a brief display of the basic facts and history of AZIBs. An insight section on zinc storage mechanism ramifications is given. A detailed discussion is conducted on features of high-performance and long life-time cathodes. Such features include design, modifications, electrochemical and cyclic performance, along with stability and zinc storage pathway of vanadium based cathodes from 2018 to 2022. Finally, this review outlines obstacles and opportunities with encouragement for gathering a strong conviction for future advancement in vanadium-based cathodes for AZIBs.

Enhanced sulfamethoxazole photodegradation by N-SrTiO3/NH4V4O10 S-scheme photocatalyst: DFT calculation and photocatalytic mechanism insight

In this study, we synthesized a N-SrTiO₃/NH₄V₄O₁₀ S-scheme photocatalyst by modifying NH₄V₄O₁₀ nanosheets with various proportions of N-doped SrTiO₃ nanoparticles using a mild hydrothermal method.Density Functional Theory(DFT) calculations were employed to elucidate thephotocatalytic mechanism, while the electron-hole transfer and separation of the S-type heterojunction were further characterized experimentally. The photocatalyst was applied to the photodegradation of sulfamethoxazole (SMX), a common water pollutant. Among all the prepared photocatalysts, 30 wt% N-SrTiO₃/NH₄V₄O₁₀ (NSN-30) displayed the highest photocatalytic performance. This was attributed to the facile electron transfer mechanism of the S-scheme heterojunction, which facilitated the effective separation of electron-holes and preserved the strong redox property of the catalyst. The possible intermediates anddegradation pathwaysin thephotocatalytic systemwere explored usingelectron paramagnetic resonance(EPR) and DFT calculations. Our findings demonstrate the potential of semiconductor catalysts to remove antibiotics from aqueous environments usinggreen energy.

De-Ammonium Ba0.18V2O4.95/NH4V4O10 Film Electrodes as High-Performance Cathode Materials for Magnesium-Ion Batteries

Magnesium-ion batteries (MIBs) have been pushed into the research boom in the post-lithium-ion batteries era due to their low cost, no dendrite hazard, and high capacity. However, finding suitable cathode materials to improve the slow kinetics of Mg2+ is an ongoing challenge. In this work, Ba0.18V2O4.95/NH4V4O10 film electrodes were grown in one step on indium tin oxide (ITO) conductive glass using a low-temperature liquid-phase deposition method. Temperature was used as the probe condition, and it was concluded that the films annealed at 400 °C had suitable crystallinity and de-ammonium lattice space. At lower current density, with 0.5 M Mg(ClO4)2/PC as the electrolyte, it exhibited an initial discharge capacity of 130.99 mA h m-2 at 210 mA m-2 and 106.52% capacity retention after 100 cycles. In addition, it exhibited excellent electrochemical performance in long-term cycling (92.98% capacity retention after 300 cycles at 600 mA m-2). According to the results of ex situ X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM), the removal of NH4+ created more lattice space, assisting Ba0.18V2O4.95 to increase the transfer channels of Mg2+, providing more active sites to promote diffusion kinetics (the average DMg2+ was 2.07 × 10-12 cm2 s-1) and specific capacity. Therefore, these film electrodes for scalable Mg2+ storage are promising MIB cathode candidates that exhibit good performance advantages in storage applications.

Intercalation-induced amorphous hydrated vanadium oxide for boosted aqueous Zn2+ storage

An amorphous hydrated vanadium oxide induced by Zn²⁺ intercalation in Mg-ion inserted V₂O₅·nH₂O (MgVOH) is developed as a high-performance cathode for ZIBs. In particular, zinc pyrovanadate as the product of the second phase transition is found to suppress the dissolution issue of the vanadium species for the cathode to facilitate long lifespan.

High-performance Zn-ion batteries constructed by in situ conversion of surface-oxidized vanadium nitride into Zn3(OH)2V2O7·2H2O with oxygen defects

Surface-oxidized vanadium nitride transforms into Zn3V2O7(OH)2-based materials with oxygen defects by electrochemical conversion, which act as cathodes for high performance aqueous zinc ion batteries.

Potassium Ammonium Vanadate with Rich Oxygen Vacancies for Fast and Highly Stable Zn-Ion Storage

Vanadium-based materials have been extensively studied as promising cathode materials for zinc-ion batteries because of their multiple valences and adjustable ion-diffusion channels. However, the sluggish kinetics of Zn-ion intercalation and less stable layered structure remain bottlenecks that limit their further development. The present work introduces potassium ions to partially substitute ammonium ions in ammonium vanadate, leading to a subtle shrinkage of lattice distance and the increased oxygen vacancies. The resulting potassium ammonium vanadate exhibits a high discharge capacity (464 mAh g^-1 at 0.1 A g^-1) and excellent cycling stability (90% retention over 3000 cycles at 5 A g^-1). The excellent electrochemical properties and battery performances are attributed to the rich oxygen vacancies. The introduction of K⁺ to partially replace NH₄⁺ appears to alleviate the irreversible deammoniation to prevent structural collapse during ion insertion/extraction. Density functional theory calculations show that potassium ammonium vanadate has a modulated electron structure and a better zinc-ion diffusion path with a lower migration barrier.

Ammonium vanadate electrode materials with stable layered structures for rechargeable zinc ion battery

As electricity demand grows, it is important to develop some energy storage systems with long cycle life and high specific capacity. Aqueous Zn ion batteries (AZIBs) are emerging storage energy...

(NH4 )2 V7 O16 Microbricks as a Novel Anode for Aqueous Lithium-Ion Battery with Good Cyclability

Searching for novel anode materials to address the issues of poor cycle stability in the aqueous lithium-ion battery system is highly desirable. In this work, ammonium vanadium bronze (NH₄ )₂ V₇ O₁₆ with brick-like morphology has been investigated as an anode material for aqueous lithium-ion batteries and Li⁺ /Na⁺ hybrid ion batteries. The two novel full cell systems (NH₄ )₂ V₇ O₁₆ ||Li₂ SO₄ ||LiMn₂ O₄ and (NH₄ )₂ V₇ O₁₆ ||Na₂ SO₄ ||LiMn₂ O₄ both demonstrate good rate capability and excellent cycling performance. A capacity retention of 78.61 % after 500 cycles at 300 mA g^-1 was demonstrated in the (NH₄ )₂ V₇ O₁₆ ||Li₂ SO₄ ||LiMn₂ O₄ system, whereas no capacity attenuation is observed in the (NH₄ )₂ V₇ O₁₆ ||Na₂ SO₄ ||LiMn₂ O₄ system. The reaction mechanisms of the (NH₄ )₂ V₇ O₁₆ electrode and impedance variation of the two full cells were also researched. The excellent cycling stability suggests that layered (NH₄ )₂ V₇ O₁₆ can be a promising anode material for aqueous rechargeable lithium-ion batteries.

Self-assembled (NH4)2V7O16 hierarchical structures with improved electrochemical performance for aqueous Li-ion batteries

(NH4)2V7O16 hierarchical structures were successfully prepared via a rotating hydrothermal method and exhibited superior long-term cyclic stability.