Facile Synthesis of Sulfur-Polypyrrole as Cathodes for Lithium-Sulfur Batteries

To explore the potential application of lithium-sulfur batteries (LSBs) in the emerging electric vehicle market, sulfur-polypyrrole (S-PPy) is prepared by a facile ball-milling route, in which polypyrrole is synthesized by using ferric chloride as an oxidant in a self-degrading template method. Compared with sulfur, S-PPy possesses a higher discharge capacity, much better cycling stability, and better rate performance. At a current density of 200mAg-1, the discharge capacity of S-PPy is maintained at 675mAhg-1 after 150cycles, and even at a current density of 1675mAg-1, the retained discharge capacity is still 617mAhg-1 after 100cycles. The retained discharge capacity of pure sulfur, however, is only 150mAhg-1 after 150cycles at a current density of 200mAg-1. These results indicate that S-PPy, with its facile, low-cost, and eco-friendly synthesis, could be a potential cathode material for LSBs.