Improving the Performance of Lithium-Sulfur Batteries by Employing Polyimide Particles as Hosting Matrixes

Sulfur cathodes with four polyimide (PI) compounds as hosting matrixes have been prepared through a simple one-step approach. These four PIs-S composites exhibited higher sulfur utilization and better cycling stability than pure sulfur. At a current rate of 300 mA g^-1, the initial discharge capacities of PI-1S, PI-2S, PI-3S, and BBLS reached 1120, 1100, 1150, and 1040 mAh g^-1, respectively. After the 30th cycle, PI-1S, PI-2S, PI-3S, BBLS and pristine sulfur powder still remained discharge capacities of 715, 673, 729, 643, and 550 mAh g^-1. Especially, PI-1S and PI-3S cathodes exhibit excellent cycling stability with the discharge capacities of 522 and 574 mAh g^-1 at the 450th cycle, respectively.