One step synthesis of vanadium pentoxide sheets as cathodes for lithium ion batteries

Thermolysis-Driven Growth of Vanadium Oxide Nanostructures Revealed by In Situ Transmission Electron Microscopy: Implications for Battery Applications

Understanding the growth modes of 2D transition-metal oxides through direct observation is of vital importance to tailor these materials to desired structures. Here, we demonstrate thermolysis-driven growth of 2D V₂O₅ nanostructures via in situ transmission electron microscopy (TEM). Various growth stages in the formation of 2D V₂O₅ nanostructures through thermal decomposition of a single solid-state NH₄VO₃ precursor are unveiled during the in situ TEM heating. Growth of orthorhombic V₂O₅ 2D nanosheets and 1D nanobelts is observed in real time. The associated temperature ranges in thermolysis-driven growth of V₂O₅ nanostructures are optimized through in situ and ex situ heating. Also, the phase transformation of V₂O₅ to VO₂ was revealed in real time by in situ TEM heating. The in situ thermolysis results were reproduced using ex situ heating, which offers opportunities for upscaling the growth of vanadium oxide-based materials. Our findings offer effective, general, and simple pathways to produce versatile 2D V₂O₅ nanostructures for a range of battery applications.

Facile Synthesis of Two Dimensional (2D) V2O5 Nanosheets Film towards Photodetectors

Most of the studies focused on V₂O₅ have been devoted to obtaining specific morphology and microstructure for its intended applications. Two dimensional (2D) V₂O₅ has the most valuable structure because of its unique planar configuration that can offer more active sites. In this study, a bottom-up and low-cost method that is hydrothermal combined with spin-coating and subsequent annealing was developed to prepare 2D V₂O₅ nanosheets film on quartz substrate. First, VOOH nanosheets were prepared by the hydrothermal method using V₂O₅ powders and EG as raw materials. Further, V₂O₅ nanosheets with an average lateral size over 500 nm and thickness less than 10 nm can be prepared from the parent VOOH nanosheets by annealing at 350 °C for 15 min in air. The prepared V₂O₅ nanosheets film was assembled of multiple nanosheets. The structural, morphological, microstructural and optical properties of the films were respective investigated by XRD, SEM, TEM and UV-Vis. The photodetector based on V₂O₅ nanosheets film shows good photoresponse with a response time of 2.4 s and a recovery time of 4.7 s.

Enhanced capacitive performance of a Ag-functionalized low crystalline Co3O4/graphene composite

The addition of Ag increased the capacitance of Co3O4 nanowires by about 5.8 times.

Fully Integrated Design of a Stretchable Solid-State Lithium-Ion Full Battery

A solid-state lithium-ion battery, in which all components (current collector, anode and cathode, electrolyte, and packaging) are stretchable, is introduced, giving rise to a battery design with mechanical properties that are compliant with flexible electronic devices and elastic wearable systems. By depositing Ag microflakes as a conductive layer on a stretchable carbon-polymer composite, a current collector with a low sheet resistance of ≈2.7 Ω □^-1 at 100% strain is obtained. Stretchable electrodes are fabricated by integrating active materials with the elastic current collector. A polyacrylamide-"water-in-salt" electrolyte is developed, offering high ionic conductivity of 10^-3 to 10^-2 S cm^-1 at room temperature and outstanding stretchability up to ≈300% of its original length. Finally, all these components are assembled into a solid-state lithium-ion full cell in thin-film configuration. Thanks to the deformable individual components, the full cell functions when stretched, bent, or even twisted. For example, after stretching the battery to 50%, a reversible capacity of 28 mAh g^-1 and an average energy density of 20 Wh kg^-1 can still be obtained after 50 cycles at 120 mA g^-1 , confirming the functionality of the battery under extreme mechanical stress.

V2O5-Based nanomaterials: synthesis and their applications

Comprehensive depiction the phase-pure V₂O₅ with unique 1D, 2D, and 3D nanostructures. Illustrate the development of carbonaceous materials into the V₂O₅ electrodes. Introduce the cation doped V₂O₅ samples as the cathode material.

Enhanced lithium storage performance of V2O5 with oxygen vacancy

Orthorhombic phase V₂O₅ nanosheets with a high V⁴⁺ content (V-V₂O₅) have been fabricated via a facile sol–gel method and freeze-drying technology followed with a vacuum annealing process.

Facile Synthesis of V₂O₅ Hollow Spheres as Advanced Cathodes for High-Performance Lithium-Ion Batteries

Three-dimensional V₂O₅ hollow structures have been prepared through a simple synthesis strategy combining solvothermal treatment and a subsequent thermal annealing. The V₂O₅ materials are composed of microspheres 2–3 μm in diameter and with a distinct hollow interior. The as-synthesized V₂O₅ hollow microspheres, when evaluated as a cathode material for lithium-ion batteries, can deliver a specific capacity as high as 273 mAh·g⁻¹ at 0.2 C. Benefiting from the hollow structures that afford fast electrolyte transport and volume accommodation, the V₂O₅ cathode also exhibits a superior rate capability and excellent cycling stability. The good Li-ion storage performance demonstrates the great potential of this unique V₂O₅ hollow material as a high-performance cathode for lithium-ion batteries.

Synthesis and electrochemical performance of hierarchical nano-vanadium oxide

Hierarchically structured nano-vanadium oxides with different morphologies have been synthesized via a template-free hydrothermal route by adjusting the organic precursor quantities. The effects of molar ratio on structure, morphology and crystallite sized were investigated. The possible growth mechanism is also proposed. When evaluated as a cathode material for lithium-ion batteries, the vanadium oxyhydroxide H2V3O8 samples deliver very high charging capacity, good reversibility and a better cycling stability. The excellent electrochemical performance is attributed to multiple advantageous structural features.