Hierarchical hybrid of n-doped carbon sheets-wrapped tungsten oxide nanoparticles for enhanced Li ion storage

Abstract

Herein, we introduce a simple method to construct a hierarchical hybrid (termed as WO3/NC) by wrapping WO3 nanoparticles with nitrogen-doped carbon nanosheets which originate from pyrolyzation of folic acid. The as-prepared hybrid presents multihole nanostructures and desirable large surface areas, which are conductive to access of electrolyte and ion diffusion, particle dispersion and alleviation of volume change. Meanwhile, intimate contraction of WO3 nanoparticles with carbon sheets enhances electroconductivity of hybrid and facilitates electron transportation in electrode reaction. Therefore, as a negative electrode for Li ion battery, the electrochemical property of the as-synthesized WO3/NC hybrid is largely boosted. Compared with bare WO3 anode, the hybrid electrode exhibited a higher Li-storage capacity value of 588.2 mAh g−1 with a more stable cycling ability during 150 cycles under 0.1 A g−1. Moreover, at 0.2, 0.5 and 1 A g−1, WO3/NC electrode delivered an enhanced rate capability and the specific capacity could attain 500.5, 385.4 and 239.6 mAh g−1. The vastly promoted electrochemical performance for Li-storage of WO3/NC could be associated with to its advantageous hierarchical architecture and optimized component.