Large Intercalation Pseudocapacitance in 2D VO<sub>2</sub> (B): Breaking through the Kinetic Barrier.

Xia, Chuan; Lin, Zifeng; Zhou, Yungang; Zhao, Chao; Liang, Hanfeng; Rozier, Patrick; Wang, Zhiguo; Alshareef, Husam N · Adv Mater · 2018

basic_science · Level V

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Abstract

VO<sub>2</sub> (B) features two lithiation/delithiation processes, one of which is kinetically facile and has been commonly observed at 2.5 V versus Li/Li<sup>+</sup> in various VO<sub>2</sub> (B) structures. In contrast, the other process, which occurs at 2.1 V versus Li/Li<sup>+</sup> , 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<sub>2</sub> (B) greatly lowers the interaction energy and Li<sup>+</sup> -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<sub>2</sub> (B) exhibits fast charge storage kinetics and enables fully reversible uptake and removal of Li ions from VO<sub>2</sub> (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.