Nano Research

Article Title

Designing of multifunctional and flame retardant separator towards safer high-performance lithium-sulfur batteries


metal-organic-frameworks, shuttle behavior, lithium dendrites, flame retardancy


Owing to unprecedented merits such as high theoretical capacity, superior energy density and low cost, lithium-sulfur batteries (LSBs) show a bright future both in scientific and industrial areas. Whereas, the inherent issues, including highly insulating character, undesired shuttle behavior and lithium dendrites growth, are seriously impeding its practical usage. Here, a metal-organic-frameworks (MOFs) derived N, S co-doped carbon nanotube hollow architecture confining with CoS2 nanoparticles (CoS2/NSCNHF) modified separator is designed to surmount these obstacles. Compared with Celgard separator, this designed separator shows obviously enhanced flame retardancy, giving 73.1% and 53.0% reductions in peak heat release rate and total heat release, separately. Concretely, its hollow structure, conductive feature, electrocatalytic activity and Lewis acid-base interaction enable the efficient inhibition on shuttle behavior as well as boost in polysulfides conversion kinetics. The cell with modified separator delivers a high discharge capacity of 1, 284.5 mAh·g–1. After running for 100 cycles, a discharge capacity of 661.3 mAh·g–1 is remained. Markedly, the suppression on lithium dendrites growth is also observed, manifesting the enhanced battery safety. Overall, this work may shed light on the effective usage of MOFs-derived hierarchical composite in achieving LSBs with high electrochemical performance as well as safety.