Graphene oxide-crowned poly(acrylonitrile)/sulfur as a lithium–sulfur battery cathode: performance and characterization

Abstract

Polyacrylonitrile (PAN), and graphene oxide (GO), as conductive constituents, were made into a PAN/S/GO composite with sulfur by a solution processing technique. Morphological examination showed that the sulfur and PAN in the composite were wrapped by highly conducting wrinkled layers of GO, aiding in higher utilization of the active mass. The composite exhibited good cycling stability. The first-cycle capacity obtained with PAN/S/GO was 1402 mAh g −1 at 0.1 C rate with a Coulombic efficiency of 99%; furthermore, it delivered a capacity of 1096 mAh g −1 in the 50th cycle, which was higher than that of and S/GO composites. The improved performance is attributed to the adsorptive properties of GO as well as surface functional groups in GO, which aid in confining polysulfide species within the cathode architecture.

Micro-/mesoporous nature of carbon nanofiber/silica matrix as an effective sulfur host for rechargeable lithium–sulfur batteries

“…The second peak at 2.05 V is ascribed to the further reduction of these soluble lithium polysulfides to short-chain lithium polysulfides (Li 2 S 2 /Li 2 S). Only one anodic peak was observed during the oxidation process at the range of 2.38 V, which attributes to the transformation of lithium sulfides into elemental sulfur (S 8 ) [38][39][40]. It is concluded that the cathodic and anodic peak currents of the F2 cathode is higher than that of F1, demonstrating an improved electrochemical kinetics and a better sulfur utilization due to the coating of SiO 2 -CNF composite on the sulfur cathode [41].…”