Freestanding V ₅ O ₁₂  · 6H ₂ O‐CNTs composite films as cathode for foldable aqueous zinc‐ion batteries

Abstract

Advanced wearable portable electronic products are needed energy storage devices with foldable properties. Zinc-ion batteries (ZIBs) are one of the most promising alternatives for energy storage devices due to their significant advantages, such as low cost, high reliability, and safety for folding. Herein, V 5 O 12 Á 6H 2 O (VOH) was obtained by facile electrodeposition strategy on carbon nanotube (CNTs) film, forming the freestanding V 5 O 12 Á 6H 2 O-CNTs (VOH-CNTs) composite films. The resultant VOH-CNTs composite films with high mechanical properties can be directly used as the cathode for foldable aqueous zinc-ion batteries (AZIBs). The VOH-CNTs electrode at a current density of 1 A g À1 shows a high specific capacity of 356 mAh g À1 and the capacity retention of 96% after 500 cycles. Even a reversible specific capacity of 292 mAh g À1 can be achieved at a current density of 5 A g À1 and the capacity retention of 93% after 4000 cycles. A high coulombic efficiency stays nearly 100%. The electrochemical properties of the prepared cells measured in different folding states remain stable, indicating the devices are suitable for use as foldable energy storage devices.

Enhancing the performance of aqueous zinc ion battery cathodes with a floral spherical V5O12·6H2O/V6O13/CNT nanocomposite

“…1(c-f). 28,29 These XPS findings provide comprehensive insights into the composition and valence states of the VOH/CNT nanocomposite.…”

“…1f exhibits peaks at 533.2 eV (H–O–H), 531.4 eV (surface-adsorbed V–OH), and 529.7 eV (lattice oxygen species V–O–V). 28,29 These XPS findings provide comprehensive insights into the composition and valence states of the VOH/CNT nanocomposite.…”

Unlocking the Potential of Vanadium Oxide for Ultrafast and Stable Zn2+ Storage Through Optimized Stress Distribution: From Engineering Simulation to Elaborate Structure Design

“…[33] In addition, the O 1s high-resolution spectra can be fitted to lattice oxygen (530.9 eV) and H 2 O molecules (531.7 eV) as shown in Figure S3b, Supporting Information. [34] In addition, rich defects can be observed in the crystal lattice as shown in Figure 2d (the selected area of the white circles), which can reduce the valence of V. [15,35] Therefore, the fitting area between V 5+ and V 4+ is lower than 4:1. Nitrogen adsorption and desorption tests are performed on VO-NSs and VO-NFs (Figure 2h).…”