Intertwined Nitrogen-Doped Carbon Nanotube Microsphere as Polysulfide Grappler for High-Performance Lithium-Sulfur Batteries

A kind of yarn-like nitrogen-doped carbon nanotubes microsphere (NSCNT) is synthesized in one-step synthesis, and sulfur is added by melting immersion to form carbon nanotube microspheres/sulfur composites (NSCNT/S). The morphology, structure and electrochemical property of the obtained NSCNT/S are explored by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and electrochemical tests. The results show that NSCNT possesses a high N content and unique mesoporous carbon framework with large specific surface area of 1029 m(2) g(-1), which can not only favor rapid electron and Li-ion transfer but also effectively mitigate dissolved polysulfides via strong chemical and physical adsorption. Due to the synergetic interaction of NSCNT, the NSCNT/S delivers a high initial discharge capacity of 1241.3 mAh g(-1) at 0.1 C and large rate capacity of 1175.5 mAh g(-1) at 1 C with ultralow capacity decay of 0.1% per cycle and high areal mass loading of 3.1 mg cm(-2). This eco-friendly NSCNT/S can offer an appealing improvement for the applications of high-performance lithium-sulfur batteries.