Neuromorphic nanoelectronic devices that can emulate the temperature-sensitive dynamics of biological neurons are of great interest for bioinspired robotics and advanced applications such as in silico neuroscience. In this work, we demonstrate the biomimetic thermosensitive properties of two-terminal V3O5 memristive devices and showcase their similarity to the firing characteristics of thermosensitive biological neurons. The temperature-dependent electrical characteristics of V3O5-based memristors are used to understand the spiking response of a simple relaxation oscillator. The temperature-dependent dynamics of these oscillators are then compared with those of biological neurons through numerical simulations of a conductance-based neuron model, the Morris-Lecar neuron model. Finally, we demonstrate a robust neuromorphic thermosensation system inspired by biological thermoreceptors for bioinspired thermal perception and representation. These results not only demonstrate the biorealistic emulative potential of threshold-switching memristors but also establish V3O5 as a functional material for realizing solid-state neurons for neuromorphic computing and sensing applications.

Layered vanadium-based oxides have emerged as highly promising candidates for aqueous zinc-ion batteries (AZIBs) due to their open-framework layer structure and high theoretical capacity among the diverse cathode materials investigated. However, the susceptibility to structural collapse during charge-discharge cycling severely hampers their advancement. Herein, we propose an effective strategy to enhance the cycling stability of vanadium oxides. Initially, the structural integrity of the host material is significantly reinforced by incorporating bi-cations Na+ and NH4 + as \"pillars\" between the V2O5 layers (NaNVO). Subsequently, surface coating with polyaniline (PA) is employed to further improve the conductivity of the active material. As anticipated, the assembled Zn//NaNVO@PA cell exhibits a remarkable discharge capacity of 492 mAh g-1 at 0.1 A g-1 and exceptional capacity retention up to 89.2 % after 1000 cycles at a current density of 5 A g-1. Moreover, a series of in-situ and ex-situ characterization techniques were utilized to investigate both Zn ions insertion/extraction storage mechanism and the contribution of polyaniline protonation process towards enhancing capacity.

Owing to their rich structural chemistry and unique electrochemical properties, vanadium-based materials, especially the low-dimensional ones, are showing promising applications in energy storage and conversion. In this invited review, low-dimensional vanadium-based materials (including 0D, 1D, and 2D nanostructures of vanadium-containing oxides, polyanions, and mixed-polyanions) and their emerging applications in advanced alkali-metal-ion batteries (e.g., Li-ion, Na-ion, and K-ion batteries) are systematically summarized. Future development trends, challenges, solutions, and perspectives are discussed and proposed. Mechanisms and new insights are also given for the development of advanced vanadium-based materials in high-performance energy storage and conversion.

Monolayer vanadium oxide films grown on Pt(111) can be reversibly switched between an oxygen-poor and an oxygen-rich composition, equivalent to V2O3 and V2O5, respectively. While the overall oxygen storage capacity of the film is quantified by X-ray photoelectron spectroscopy, the atomic binding sites of the extra O species are determined by low-temperature scanning tunneling microscopy and electron diffraction. In the O-poor phase, the oxide takes the form of a honeycomb lattice that gets partially covered with vanadyl (V=O) groups at higher O exposure. Upon transition to the O-rich phase, isolated V6O12 rings emerge in the film first, which then evolves towards a disordered O-V-O trilayer on the Pt(111) surface. Our works thus unravels the microscopic nature of reversible oxygen storage in a model system for heterogeneous catalysis.

Vanadium dioxide-based materials have been proved to be promising cathodes for aqueous zinc ion batteries (AZIBs) due to their cost-effectiveness and high theoretical specific capacity; nevertheless, the low electronic conductivity and poor cycle stability restrict their application. Herein, hollow VO2 microspheres anchored on graphene oxide (H-VO2@GO) are synthesized via a facile simple hydrothermal reaction as high-performance cathodes for AZIBs. The hollow micromorphology of the material provides a large specific surface area and effectively alleviates the volume changes during cycling, while the anchoring of VO2 on graphene oxide greatly improves the electronic conductivity and inhibits the agglomeration and pulverization of the material. Resulting from the combination of unique micromorphology and graphene oxide anchoring, the as-prepared H-VO2@GO exhibits the impressive specific capacity of 400.1 mAh/g at 0.5 A/g and excellent cycling performance with 96.1 % of capacity retention after 1500 cycles at 10 A/g. This investigation provides a use reference for designing high-performance cathodes materials for AZIBs by optimizing the microstructure of electrode materials.

Vanadium oxides are excellent cathode materials with large storage capacities for aqueous zinc-ion batteries, but their further development has been hampered by their low electronic conductivity and slow Zn2+ diffusion. Here, an electrochemically induced phase transformation strategy is proposed to mitigate and overcome these barriers. In situ X-ray diffraction analysis confirms the complete transformation of tunnel-like structural V6O13 into layered V5O12·6H2O during the initial electrochemical charging process. Theoretical calculations reveal that the phase transformation is crucial to reducing the Zn2+ migration energy barrier and facilitating fast charge storage kinetics. The calculated band structures indicate that the bandgap of V5O12·6H2O (0.0006 eV) is lower than that of V6O13 (0.5010 eV), which enhanced the excitation of charge carriers to the conduction band, favoring electron transfer in redox reactions. As a result, the transformed V5O12·6H2O delivers a high capacity of 609 mA h g-1 at 0.1 A g-1, superior rate performance (300 mA h g-1 at 20 A g-1), fast-charging capability (<7 min charging for 465 mA h g-1), and excellent cycling stability with a reversible capacity of 346 mA h g-1 at 5 A g-1 after 5000 cycles.

Vanadium is a strategic metal that has many important industrial applications and is generated by the use of burning fossil fuels, which inevitably leads to their release into the environment, mainly in the form of oxides. The wastes generated by their use represent a major health hazard. Furthermore, it has attracted attention because several genotoxicity studies have shown that some vanadium compounds can affect DNA; among the most studied compounds is vanadium pentoxide, but studies in vivo with oxidation states IV and III are scarce and controversial. In this study, the genotoxic and cytotoxic potential of vanadium oxides was investigated in mouse bone marrow cells using structural chromosomal aberration (SCA) and mitotic index (MI) test systems. Three groups were administered vanadium(IV) tetraoxide (V2O4) intraperitoneally at 4.7, 9.4 or 18.8 mg/kg, and three groups were administered vanadium(III) trioxide (V2O3) at 4.22, 8.46 or 16.93 mg/kg body weight. The control group was treated with sterile water, and the positive control group was treated with cadmium(II) chloride (CdCl2). After 24 h, all doses of vanadium compounds increased the percentage of cells with SCA and decreased the MI. Our results demonstrated that under the present experimental conditions and doses, treatment with V2O4 and V2O3 induces chromosomal aberrations and alters cell division in the bone marrow of mice.

Cation-intercalated vanadates, which have considerable promise as the cathode for high-performance potassium metal batteries (PMBs), suffer from structural collapse upon K+ insertion and desertion. Exotic cations in the vanadate cathode may ease the collapse, yet their effect on the intrinsic cation remains speculative. Herein, a stable and dendrite-free PMB, composed of a Na+ and K+ co-intercalated vanadate (NKVO) cathode and a liquid NaK alloy anode, is presented. A series of NKVO with tuneable Na/K ratios are facilely prepared using MXene precursors, in which Na+ is testified to be immobilized upon cycling, functioning as a structural pillar. Due to stronger ionic bonding and lower Fermi level of Na+ compared to K+ , moderate Na+ intercalation could reduce K+ binding to the solvation sheath and favor K+ diffusion kinetics. As a result, the MXene-derived Na+ -pillared NKVO exhibits markedly improved specific capacities, rate performance, and cycle stability than the Na+ -free counterpart. Moreover, thermally-treated carbon paper, which imitates the microscopic structure of Chinese Xuan paper, allows high surface tension liquid NaK alloy to adhere readily, enabling dendrite-free metal anodes. By clarifying the role of foreign intercalating cations, this study may lead to a more rational design of stable and high-performance electrode materials.

Currently, the development of calcium-ion batteries (CIBs) is still in its infancy and greatly plagued by the absence of satisfactory cathode materials and compatible electrolytes. Herein, an acetonitrile-water hybrid electrolyte is first developed in CIB chemistry, in which, the strong lubricating and shielding effect of water solvent significantly boosts the swift transport of bulky Ca2+, thus contributing to large capacity storage of Ca2+ in layered vanadium oxides (Ca0.25V2O5·nH2O, CVO). Meanwhile, the acetonitrile component noticeably suppresses the dissolution of vanadium species during repeated Ca2+-ion uptake/release, endowing the CVO cathode with a robust cycle life. More importantly, spectral characterization and molecular dynamics simulation confirm that the water molecules are well stabilized by the mutual hydrogen bonding with acetonitrile molecules (O-H···N), endowing the aqueous hybrid electrolyte with high electrochemical stability. By using this aqueous hybrid electrolyte, the CVO electrode shows a high specific discharge capacity of 158.2 mAh g-1 at 0.2 A g-1, an appealing capacity of 104.6 mAh g-1 at a high rate of 5 A g-1, and a capacity retention of 95% after 2000 cycles at 1.0 A g-1, which is a record-high performance for CIBs reported so far. A mechanistic study exemplifies the reversible extraction of Ca2+ from the gap of VO polyhedral layers, which are accompanied by the reversible V-O and V-V skeleton change as well as reversible variation of layer spacing. This work constitutes a major advance in developing high-performance Ca-ion batteries.

Much of the earth\'s water has a salt content that is too high for human consumption or agricultural use. Enhanced oil recovery operations generate massive volumes of produced water waste with a high mineral content that can substantially exacerbate water distress. Current deionization techniques such as reverse osmosis function by removing the water (majority phase) from the salt (minority phase) and are thus exceedingly energy-intensive. Furthermore, these methods are limited in their ability to selectively extract high-value ions from produced water waste and brine streams. Hybrid capacitive deionization holds promise for enabling both desalination and resource recovery. In this work, we demonstrate the construction of a hybrid capacitive deionization cell that makes use of tunnel-structured ζ-V2O5 as a redox-active positive electrode material. By augmenting surface adsorption with Faradaic insertion processes, a 50% improvement in the ion removal capacity for K and Li ions is obtained as compared to a capacitive high-surface-area carbon electrode. The extracted ions are accommodated in surface sites and interstitial sites within the one-dimensional tunnel framework of ζ-V2O5. The kinetics of ion removal depend on the free energy of hydration, which governs the ease of desolvation at the electrode/electrolyte interface. The overall ion removal capacity additionally depends on the solid-state diffusion coefficient. ζ-V2O5 positive electrodes show substantial selectivity for Li+ removal from mixed flow streams and enrichment of the Li-ion concentration from produced water waste derived from the Permian Basin.