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

VO₂ (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 VO₂ (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 VO₂ (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 VO₂ (B) exhibits fast charge storage kinetics and enables fully reversible uptake and removal of Li ions from VO₂ (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.