Encapsulating V2O5 into carbon nanotubes enables the synthesis of flexible high-performance lithium ion batteries

Abstract

Here, we have designed and successfully fabricated an interwoven nanocable architecture constructed by V₂O₅ nanosheets encapsulated within multi-graphitic nanotubes as a novel high performance flexible cathode for Li ion batteries. Such an integrated electrode designed via the multiscale system exhibits ultrafast and stable Li ion storage performance, with a capacity higher than 90 mA h g⁻¹ even at 100 C and only 0.04% capacity decay per cycle over 200 cycles. To the best of our knowledge, this is the first example of the facile synthesis of flexible V₂O₅ encapsulated into carbon nanotube positive electrodes and the successful demonstration of a flexible full cell showing surprisingly consistent cycling stability and excellent mechanical properties with V₂O₅@G as cathodes and their allotrope as anodes. Remarkably, an energy density of ca. 360 W h kg⁻¹ at a power rate of 15.2 kW kg⁻¹ is achieved, which belongs to one of the best results reported so far on V₂O₅-based electrode materials. Coupled with a simple and scalable production protocol, the strategies are highly promising for both novel cathode exploration and for the practical fabrication and application of flexible energy storage devices.