Polypyrrole-coated loose network mesoporous carbon/sulfur composite for high-performance lithium-sulfur batteries

Lithium-sulfur batteries have received a lot of attention for next-generation energy storage, however, low conductivity of the sulfur cathode and shuttle of polysulfides still limit the utilization of sulfur. In this work, a polypyrrole-coated loose network mesoporous carbon/sulfur composite (C/S@PPy) was designed. In this structure, the conductive networks of mesoporous carbon are perfect hosts to contain sulfur and enhance the conductivity of the cathode; the conductive polymer-coating layer further inhibits the lithium polysulfides from dissolution and migration in the electrolyte. Compared with C/S, the C/S@PPy composite exhibited an excellent rate capability and enhanced cyclic stability. An initial discharge capacity of 1209.6 mAh g−1 was achieved for the C/S@PPy electrode in the first cycle at 0.1 C, and capacity retention of 62.2% was obtained after 300 cycles at 0.2 C.