Biomimetic 3D Fe/CeO2 decorated N-doped carbon nanotubes architectures for high-performance lithium-sulfur batteries

Abstract lithium-sulfur (Li-S) batteries have been regarded as one of the most promising systems for next-generation rechargeable batteries owing to their high energy density and low cost. However, the “Shuttle effect” of polysulfides and low sulfur utilization upon cycling are still hindering their practical applications. Herein, we report a series of marine organism-like hollow nanoarchitecture consisting of nitrogen (N) doped 1D carbon nanotubes (CNTs), which were derived from binary Fe/Ce Prussian blue analogs (PBAs) and melamine. This nitrogen-doped 3D hollow scaffold offers large inner space (ф ≈ 200 nm) and sufficient electric conducting for insulating sulfur and provides adsorption sites for immobilizing polysulphides. The introduced double metal species enable strong chemical adsorption toward polysulfides and could facilitate the redox reaction between sulfur and polysulphides. When applied in Li-S batteries, the as-prepared materials showed a high capacity of 1241 mAh g−1 and a stable cycling performance (1003 mAh g−1 after 100 cycles) at a current density of 0.2 C. The enhancement of electrochemical activity could be attributed to the 3D hollow architecture of the hybrid, in which the nitrogen-doping generates defects and active sites for improved interfacial adsorption. This work could inspire developing biomimetic architectures for high-performance Li-S batteries.