Sulfurized Polyacrylonitrile Cathode Derived from Intermolecular Cross-Linked Polyacrylonitrile for a Rechargeable Lithium Battery

Sulfurized pyrolyzed poly(acrylonitrile) (S@pPAN) has become one of the most promising cathodes for rechargeable batteries because of its high compressed density, low E/S ratio, no self-discharge, and stable cycling. However, it suffers from low sulfur content (<45 wt %), which limits the composite capacity and thereby the energy density. Herein, we prepared cross-linked PAN precursor with porous structure and high specific area via an intermolecular cross-linking method. The prepared cross-linked PAN offers more space to accommodate sulfur molecules, rendering the effective sulfur content up to 53.63 wt %. It realizes a remarkable reversible specific capacity of 829 mAh g–1composites at 0.2 C. As a result, it provides a way to prepare the S@pPAN cathodes for a lithium–sulfur battery with high energy density and good electrochemical performances.