Constructing a Multifunctional Globular Polypyrrole Slurry Cladding Carbon Aerogel/Sulfur Cathode for High-Performance Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries with their low cost, high energy density, and theoretical specific capacity have been deemed as one of the most promising candidates for the future energy storage market. However, the insulating sulfur and the shuttling effect concerning lithium polysulfides always persecute the sulfur cathode of Li-S batteries. Consequently, a globular polypyrrole (PPy) interlayer (GPIL) with multifunctional polysulfide-blocking ability wraps the carbon aerogel/sulfur cathode to restrain this shuttling effect. Ultimately, a high-performance Li-S battery is obtained through a polypyrrole coating design. The maximum discharge specific capacity of the sulfur cathode with a GPIL is 882 mAh g-1 at 1.4 mA cm-2 with the reversible specific capacity and an average Coulombic efficiency of ∼652.7 mAh g-1 and 98.1%, respectively, after 100 cycles, indicating an effective impediment of the shuttling effect. Moreover, the Li-S battery with a GPIL can still deliver 520 mAh g-1 with a capacity retention rate of >96% after 100 cycles at a high current density of 2.8 mA cm-2, significantly outstripping most of the interlayers recently reported. This work highlights the meaning of this multifunctional interlayer and also promotes the great application potential of carbon aerogel as the host of the sulfur cathode for Li-S batteries.