Cobalt-iron layered double hydroxides/CNTs composite modified separator enabling high-performance lithium–sulfur batteries

The active material loss and capacity degeneration resulted from severe shuttle effect and sluggish redox reaction kinetics of lithium polysulfides (LiPSs) have greatly hindered the further development of high-performance lithium–sulfur batteries (LiSBs). Herein, the functional polymer separator consisting of cobalt-iron layered double hydroxides (CoFe LDH)/carbon nanotubes (CNTs) modified polymer separator is developed. This CoFe LDH/CNTs composite combines the advantages of enhanced chemical bonding between CoFe LDH and LiPSs and improved conductivity, which can significantly suppress the shuttling effect of LiPSs and accelerate the redox reaction kinetics. Therefore, LiSBs assembled by CoFe LDH/CNT-modified separators exhibit superior electrochemical performance with high initial capacity (961.4 mAh g−1) and excellent cycling stability during 200 cycles at 0.5C rate. The results demonstrate that the Co-Fe LDH/CNTs composites are efficient functional separators for for high-performance LiSBs.