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

Abstract

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 200 mA g−1, the discharge capacity of S‐PPy is maintained at 675 mA h g−1 after 150 cycles, and even at a current density of 1675 mA g−1, the retained discharge capacity is still 617 mA h g−1 after 100 cycles. The retained discharge capacity of pure sulfur, however, is only 150 mA h g−1 after 150 cycles at a current density of 200 mA g−1. These results indicate that S‐PPy, with its facile, low‐cost, and eco‐friendly synthesis, could be a potential cathode material for LSBs.

A Bio‐Inspired Structurally‐Responsive and Polysulfides‐Mobilizable Carbon/Sulfur Composite as Long‐Cycling Life Li−S Battery Cathode

“…As seen, two reduction peaks at 2.23 and 1.95 V are consistent with the reactions of solid S 8 to soluble high‐order polysulfides and further to the insoluble low‐order polysulfides. The anodic peak at 2.45 V is attributed to the oxidation of polysulfides to the neutral S 8 , which is consistent with the charge/discharge plateaus shown in Figure a.…”

Free-standing sulfur-polypyrrole cathode in conjunction with polypyrrole-coated separator for flexible Li-S batteries

“…14 Therefore PPy not only acts as an electrically conducting agent, but also contributes capacity to the Li-S batteries. 15,16 Keeping these considerations in mind, we designed a free-standing sulfur-polypyrrole cathode (PPy/S@PPy) by loading sulfur coated polypyrrole (S@PPy) composite on a flexible PPy film. The as-prepared PPy film possesses a rough surface, which can enhance the adhesion of active material and further trap the dissolved polysulfides.…”

Recent advances in chemical adsorption and catalytic conversion materials for Li–S batteries

“…Similarly to PANI, other conducting polymers, such as, PPy, PTh, and PEDOT, present superior conductivity, which could compensate the insulation of sulfur, and could also be employed as obstructing layers to prevent the dissolution of LiPSs. Polypyrrole nanofibers for S-PPy nanocomposites were synthesized using methyl orange as a self-degrading template [60] . The enhanced performance of the Li-S battery using these composites was attributed to the adsorption and active interaction of conductive PPy with LiPSs.…”