A feather-like interlayer design with highly exposed active sites for high-performance lithium-sulfur batteries

Improving the conversion efficiency of lithium polysulfides (LiPSs) within the interlayer plays a significant role in inhibiting the shuttle effect of polysulfides for lithium-sulfur (Li-S) batteries, and this can be addressed by constructing highly exposed catalytic active sites. Herein, a feather-like interlayer material featured with highly exposed active sites is prepared by combining electrospinning technology and chemical vapor deposition. In the interlayer design, the growth of carbon nanotubes (CNTs) on the nitrogen-doped carbon fiber (NCF) surface greatly exposes the active Co and N-dopant adsorption-catalytic sites and forms a feather-like Co/CNT@NCF composite. The feather-like structure design endows the interlayer with good blockage effect for LiPSs shuttling. Meanwhile, the abundant active catalytic sites can effectively promote the conversion of polysulfides, and thus further suppress the shuttle of LiPSs. The cell with Co/CNT@NCF interlayer achieves excellent discharge performance (901.5 mAh g−1) with low capacity decay (0.025% per cycle) after 500 cycles at 1 C. Moreover, the cell exhibits a discharge capacity of 809 mAh g−1 at 5 C and an areal capacity of 5.05 mAh cm−2 under a sulfur loading of 6.9 mg cm−2. This work offers a facile interlayer design from the perspective of high active sites exposure in Li-S cells.