Large Intercalation Pseudocapacitance in 2D VO₂ (B): Breaking through the Kinetic Barrier

Abstract

VO (B) features two lithiation/delithiation processes, one of which is kinetically facile and has been commonly observed at 2.5 V versus Li/Li in various VO (B) structures. In contrast, the other process, which occurs at 2.1 V versus Li/Li , has only been observed at elevated temperatures due to large interaction energy barrier and extremely sluggish kinetics. Here, it is demonstrated that a rational design of atomically thin, 2D nanostructures of VO (B) greatly lowers the interaction energy and Li -diffusion barrier. Consequently, the kinetically sluggish step is successfully enabled to proceed at room temperature for the first time ever. The atomically thin 2D VO (B) exhibits fast charge storage kinetics and enables fully reversible uptake and removal of Li ions from VO (B) lattice without a phase change, resulting in exceptionally high performance. This work presents an effective strategy to speed up intrinsically sluggish processes in non-van der Waals layered materials.

Surface Amorphization of Vanadium Dioxide (B) for K‐Ion Battery

“…Figure 2f is the high‐resolution TEM (HRTEM) image of SA‐VO 2 derived from the edge of the nanorod, which presents an interplanar spacing of 0.352 nm corresponding to the (110) plane of monoclinic VO 2 . [ 7b ] Monoclinic VO 2 is homogeneously wrapped by a disordered layer with a thickness of ≈2 nm, which is probably caused by the interaction between the surface layer of VO 2 and NaHB 4 . As compared to the bare VO 2 with completely crystal texture from bulk to surface (Figure S2, Supporting Information), the obtained surface amorphous structure could possess more open channels for the migration of K + because of its isotropic structure characteristic.…”

“…Brookite phase vanadium oxide, denoted as VO 2 (B), possesses a bilayer structure with large lattice spacing formed from edge‐sharing VO 6 octahedra; [ 7 ] such structure would enable the convenient insertion/extraction of K + in double layers of V 4 O 10 structure and tolerate the volume expansion, thereby demonstrating great potential as anode for PIBs. However, its intrinsic low electronic conductivity and sluggish K + diffusion kinetics inevitably limit its electrochemical performance when applied as anode for PIBs.…”

Water‐Processable and Multiscale‐Designed Vanadium Oxide Cathodes with Predominant Zn2+ Intercalation Pseudocapacitance toward High Gravimetric/Areal/Volumetric Capacity

“…All the diffraction peaks from commercial V 2 O 5 microparticles almost disappear, implying complete transformation. [60,61] The dominant diffraction peaks of the PVO/PEDOT⊂CNTs composites can be assignable to (00l) Bragg reflections of stacked V 2 O 5 bilayers each intercalated with two monolayers of PEDOT molecules. The peak at ≈8.8° corresponds to the (002) plane of layered V 2 O 5 , suggesting that interlayer spacing is enlarged from 4.3 to 10 Å due to the intercalation of PEDOT molecules, which is similar with that reported by Alshareef et al [60] The full width at half maximum (FWHM) of the (002) peak from the PVO/PEDOT⊂CNTs composites is broader than that of the V 2 O 5 microparticles and PVO/PEDOT composites, implying a reduction in the thickness along c-axis of the PVO nanoflakes.…”

Thin Film Stabilization of Different VO2Polymorphs

“…VO 2 (B) has been long considered as a promising electrode material for Li ion batteries since the after report of Li et al in 1994 [82]. It emerged as a promising cathode material owing to its layered structure and outstanding electrochemical performance [83,84]. Also, it is important for the study of strong electronic correlations resulting from structure.…”