Synergistically Enhanced Interfacial Interaction to Polysulfide via N,O Dual-Doped Highly Porous Carbon Microrods for Advanced Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries have received tremendous attention because of their extremely high theoretical capacity (1672 mA h g–1) and energy density (2600 W h kg–1). Nevertheless, the commercialization of Li–S batteries has been blocked by the shuttle effect of lithium polysulfide intermediates, the insulating nature of sulfur, and the volume expansion during cycling. Here, hierarchical porous N,O dual-doped carbon microrods (NOCMs) were developed as sulfur host materials with a large pore volume (1.5 cm3 g–1) and a high surface area (1147 m2 g–1). The highly porous structure of the NOCMs can act as a physical barrier to lithium polysulfides, while N and O functional groups enhance the interfacial interaction to trap lithium polysulfides, permitting a high loading amount of sulfur (79–90 wt % in the composite). Benefiting from the physical and chemical anchoring effect to prevent shuttling of polysulfides, S@NOCMs composites successfully solve the problems of low sulfur utilization and fast capacity fade and exhibit a stable reversible capacity of 1071 mA h g–1 after 160 cycles with nearly 100% Coulombic efficiency at 0.2 C. The N,O dual doping treatment to porous carbon microrods paves a way toward rational design of high-performance Li–S cathodes with high energy density.