Novel Flowerlike Metastable Vanadium Dioxide (B) Micronanostructures: Facile Synthesis and Application in Aqueous Lithium Ion Batteries

Abstract

Novel flowerlike VO 2 (B) micro-nanostructures assembled by single-crystalline nanosheets have been successfully synthesized via a hydrothermal route using polymer polyvinyl pyrrolidone (PVP, K30) as capping reagent. Detailed proofs indicated that the process of crystal growth was dominated by a nucleation and growth, self-assembly, and then Ostwald ripening growth mechanism. For the first time, the flowerlike micronanostructures VO 2 (B) was applied as the active material into aqueous lithium ion battery applications, which showed improved electrochemical properties with the first discharge capacity reaching 74.9 mAhg -1 , a quite outstanding value for aqueous lithium ion battery systems in light of previous reports (usually <65 mAhg -1 ). In addition, corresponding VO 2 (B) nanostructures with better crystallinity were obtained by calcining the precursor of flowerlike VO 2 (B) structures. The post-treated flowerlike VO 2 (B) electrode shows fascinating advantages in electrochemical properties with the first discharge capacity reaching 81.3 mAhg -1 , which is higher than that of the flowerlike VO 2 (B) sample before annealing. Furthermore, we have investigated the electrochemical intercalation and deintercalation properties with Li + the synthesized VO 2 (B) nanobelts and carambola-like VO 2 (B) structure. The unique flowerlike structure plays a basic role in the morphology requirement to serve as transport paths for lithium ion in aqueous lithium ion batteries. It was observed that the morphologies and crystallinity of the synthesized products had an evident influence on the electrochemical intercalation and deintercalation properties with lithium ions.

Nanothermochromics: Calculations for VO2 nanoparticles in dielectric hosts show much improved luminous transmittance and solar energy transmittance modulation

“…97 Nanorods ͑nanoribbons, nanobelts͒ of this material have been prepared by wet chemical techniques in numerous studies 95,[98][99][100][101][102][103][104][105][106][107][108][109][110][111][112][113][114][115] and the capability for electrochemical lithium insertion has been investigated. VO 2 ͑B͒ is not in itself a good thermochromic material but it can be transformed to thermochromic VO 2 via heat treatment, as has been demonstrated for powders 116,117 and nanorods, 103,118 which means that a large body of work made with battery applications in mind is also of relevance for thermochromics.…”

Recent Advances in Nanostructured Vanadium Oxides and Composites for Energy Conversion

“…[29] Many nanostructures with higher dimensions have been successfully synthesized including nanowires, [131] nanorods, [132] nanosheets [133] and hierarchical nanostructures. [134] As shown in Figure 10a, nanowires with the diameter of 50 nm have been fabricated through a solvothermal reaction of V 2 O 5 , water and ethylene glycol. www.advancedsciencenews.com obtained.…”

“…Nanosheet-assembled structures (Figure 10e) have been fabricated using PVP as a surfactant. [134] And nanobelt-assembled urchin-like nanostructures (Figure 10f) have been prepared via a hydrothermal route using V 2 O 5 and oxalic acid. [135] This 3D assembly can be promoted by two possible routes, a higher concentration of reducing agent and higher reaction temperature.…”

“…Reproduced with permission. [134] Copyright 2009, American Chemical Society. f) SEM image of the nanobelt-assembled urchin-like VO 2 (B) nanostructure.…”

The Preparation of VO2(B) Cathode Material for Lithium-ion Battery with High Capacity and Good Cycling Performance

“…However, the defect of low electronic conductivity and poor stable circulation severely affected its practical application. In recent years, researchers have taken a series of effective measures to overcome its shortcomings, all kinds of morphologies of VO 2 (B) have been prepared, such as nanorods [15,16], nanoribbons [17,18], nanotubes [19,20], and nanowires [21], however, these nanostructure materials displayed low discharge capacity and poor cycling properties [22], The fading of the capacity was probably owing to the high surface energies and large specific surface areas, which leading to the easier aggregation of the sample during process of charging and discharging, thus resulting in the increases of the charge transfer resistance [23]. Therefore, how to improve the cycling properties of VO 2 (B) was still a great challenge for researchers and material scientists.…”