Tungsten oxide/nitrogen-doped carbon nanotubes composite catalysts for enhanced redox kinetics in lithium–sulfur batteries

The sluggish redox kinetics of polysulfides in lithium–sulfur (Li–S) batteries are a significant obstacle to their widespread adoption as energy storage devices. However, recent studies have shown that tungsten oxide (WO3) can facilitate the conversion kinetics of polysulfides in Li–S batteries. Herein, we fabricated host materials for sulfur using nitrogen-doped carbon nanotubes (N-CNTs) and WO3. We used low-cost components and simple procedures to overcome the poor electrical conductivity that is a disadvantage of metal oxides. The composites of WO3 and N-CNTs (WO3/N-CNTs) create a stable framework structure, fast ion diffusion channels, and a 3D electron transport network during electrochemical reaction processes. As a result, the WO3/N-CNT-Li2S6 cathode demonstrates high initial capacity (1162 mA·h·g−1 at 0.5 C), excellent rate performance (618 mA·h·g−1 at 5.5 C), and a low capacity decay rate (0.093% up to 600 cycles at 2 C). This work presents a novel approach for preparing tungsten oxide/carbon composite catalysts that facilitate the redox kinetics of polysulfide conversion.