Bifunctional N-Doped Tungsten Trioxide Microspheres as Electrode Materials for Lithium-Ion Batteries and Direct Methanol Fuel Cells

摘要

Oxygen vacancies (OVs) have emerged as an efficient strategy to modulate the electronic structures, conductivity, and electrochemical properties of WO3. However, OVs are easily absorbed by water molecules or oxygen atoms, resulting in the poor stability of its electrocatalytic reaction. In the present work, we have demonstrated that nitrogen doping provides an alternative to improve the electrochemical properties of WO3, which plays a series of roles in reducing the band gap, improving the electron mobility, accelerating the Li+ ion diffusion, and providing more active sites for catalytic reactions. Consequently, N-doped WO3 microspheres exhibit low discharge-charge voltage gaps and high capacity retention as well as exceptional rate performance when used as anode materials for lithium-ion batteries (LIBs). Furthermore, the as-prepared Pt/N-WO3 catalyst also exhibits excellent electrocatalytic properties toward methanol electro-oxidation (MOR) including high activity, strong poison tolerance, and outstanding long-term stability owing to the synergetic effects between Pt and N-WO3.