Nitrogen-doped carbon nanorods embedded with cobalt nanoparticles as separator coatings for high-performance lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) have a high theoretical specific capacity (1675 mAh/g) and are expected to replace lithium-ion batteries as a new generation of high-density energy storage devices. However, the existence of problems such as the “shuttle effect” causes an irreversible loss of LSB capacity. In view of this, carbon nanorods embedded with cobalt nanoparticles (Co-CNRs-CTAB) were successfully prepared through the high-temperature pyrolysis of prism-shaped polypyrrole loaded with zeolitic imidazolate framework-67 under the assistance of cetyltrimethylammonium bromide (CTAB), applied as commercial polypropylene (PP) separator modifiers to promote the rapid capture and redox conversion of soluble polysulfides for upgrading LSBs. The results show that the LSBs assembled with modified Co-CNRs-CTAB/PP separator have amazing electrochemical performance, involving a high initial mass specific capacity of 1091.8 mAh/g (1 C) and excellent cycling stability (594.7 mAh/g after 300 cycles at 3 C). Even at − 10 °C, the capacity attenuation of the LSBs per cycle is only 0.05