Stabilization of Sulfur Cathode with Poly-peri-naphthalene for High Electrochemical Performance

With the layered structure and high conductivity similar to those of graphite, the conductive polymer poly-peri-naphthalene was used to modify sulfur electrode Structure and properties of PPN, and the sulfur/Poly-peri-naphthalene (S/PPN) composite were characterized using IR, Raman spectroscopy, x-ray diffraction, thermogravimetry, and scanning electron microscopy. Compared with carbon/sulfur composite cathode, the S/PPN cathode showed superior discharge capacity, high cycle stability and low electrochemical impedance. An initial discharge capacity of 1084.2 mAh g⁻¹ was delivered using the S/PPN cathode at a current density of 400 mA g⁻¹, while the discharge capacity of 919.7 mAh g⁻¹ was remained after 50 cycles. PPN played a role of framework in the S/PPN electrode, which can stabilize the sulfur in the charge/discharge processes.