Free-standing cross-linked hollow carbonaceous nanovesicle fibers with atomically dispersed CoN4 electrocatalytic centers driving high-performance Li-S battery

Atomically distributed CoN4 moieties within free-standing cross-linked hollow carbonaceous nanovesicle fibers (CoNCNF) are fabricated by electrostatic spinning following with thermal treatment. The conductive hollow carbonaceous nanovesicles are favorable for storage of electrolytes and fast transmission of electrons. The CoN4 sites of CoNCNF film provide high-efficiency electrocatalytic sites for approving lithium polysulfides capture and fast kinetic transformation suppressing the shuttle effect. Using as cathode-separator interlayer, the CoNCNF-based Li-S battery presents a high initial capacity of 1023.9 mAh g−1 and an ideal capacity of 746.2 mAh g−1 maintains after 1000 cycles at 1 C. Interestingly, it easily performs 5000 cycles at a low decay rate of 0.016% at 2 C. Even at a high current density of 5 C, it provides an excellent capacity of 812.6 mAh g−1. Surprisingly, it has a very high areal capacity of 10.7 mAh cm−2 when the cathode S mass loading is up to 12.5 mg cm−2.