▎ 摘　　要

It is still a grand challenge to achieve high performance lithium-sulfur (Li-S) batteries of high capacity, high-rate performance and long cycling performance, especially at lean electrolyte condition. Herein, a multi-functional composite interlayer is developed by in-situ polymerizing pyrrole (PPy) on graphene nanosheet (PPy/G) and examined by Fourier Transformed infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy. The graphene layers in PPy/G assure the high conductivity of the composite interlayer, while the high content of pyrrolic nitrogen sites of PPy in PPy/G composite interlayer can effectively trap the polysulfides (PSs) and promote the redox kinetics of PSs, which is valuable to suppress PSs dissolution and enhance utilization of sulfur content in Li-S batteries. Besides, the composite interlayer also facilitates the homogenous flux of Li+ and inhibits the growth of Li dendrite on Li metal anode. As a result, PPy/G interlayer delivers an impressive capacity of 535 mAh g(-1) at 5 C and an area capacity of 5.18 mAh cm(-2) at a sulfur load of 5.8 mg cm(-2) after 100 cycles. A steady capacity of 664 mAh g(-1) is also accomplished in lean-electrolyte condition after 100 cycles.