Poly(4‐styrene sulfonic acid) to Disperse Graphene for Applications in Lithium‐Sulfur Batteries

Abstract The use of poly(4‐styrene sulfonic acid) (PSSA) to effectively disperse graphene in an aqueous sulfur (S) cathode slurry is proposed, and the cell performance of the resulting Li−S battery is investigated and compared to that of the battery prepared by adding as‐received graphene. The addition of PSSA improves not only the dispersion of the as‐received graphene, but also the homogeneity of the constituents in the S cathode slurry; accordingly, better electronic and ionic conductivities are obtained. The electrical impedance of the cell constructed using the S cathode with the as‐received graphene is greatly reduced from 142.0 to 14.6 Ω when PSSA is added during the preparation of the cathode. Moreover, the addition of the PSSA‐dispersed graphene to the S cathode significantly improves the capacity, cycle life, and coulombic efficiency during the charge‐discharge process, since PSSA increases the contact between the dispersed graphene and the insulated S powder.