Fe/Fe3C@graphitic carbon shell embedded in carbon nanotubes derived from Prussian blue as cathodes for Li–O2 batteries

Abstract

The effective design and facile preparation of noble metal-free catalysts is crucial for enhancing the performance of rechargeable Li–O₂ batteries. Herein, we report a one-step controlled pyrolysis method to synthesize a Fe/Fe₃C@graphitic carbon shell embedded in carbon nanotubes composite (F@NG-NCNTs) with Prussian blue as the single precursor. In these nanostructures, the Fe/Fe₃C centres induce the formation of self-assembled N-doped carbon frameworks, which in turn offer superior connectivity as well as a protective coating. This novel architecture not only promotes the transfer of electrons but also uniformly encapsulates the catalytically active Fe/Fe₃C nanoparticles, leading to a remarkably enhanced performance in Li–O₂ batteries. As a result, cells catalyzed by the F@NG-NCNTs deliver a higher initial discharge capacity (6966 mA h g⁻¹ at a current density of 0.1 mA cm⁻²) and demonstrate outstanding rate capability and cycle stability. This study verifies that F@NG-NCNTs can be a promising cathode material and provides a new avenue for the effective nanostructural design of electrocatalysts.