Low-Temperature Synthesis of a Sulfur-Polyacrylonitrile Composite Cathode for Lithium-Sulfur Batteries

Abstract

Through a novel synthesis process, a novel sulfurized polyacrylonitrile (SPAN) composite, noted as DH-150-300-SPAN, was prepared and tested as cathode material for lithium sulfur (Li−S) batteries. The reported process involves two heating steps at low temperature. The first plateau at 150 °C melts elemental sulfur, while the second, at 300 °C, produces the cycling of polyacrylonitrile, and incorporates sulfur to the cyclic polymeric structure. A fully morphological and electrochemical characterization was carried out. The SPAN composite contains (38.3 ± 0.2) % S. Li−S batteries assembled using these cathodes have shown good performance, reaching high and stable capacity values, above 1000 mAh (Formula presented.) after 150 cycles at 0.1 C. This is the first time that stable cycling is achieved for a SPAN composite synthesized at such low temperatures and for short heating treatments. Our work describes an easy route to prepare a promising candidate for cathode material of Li−S batteries by using a low-cost process and low-cost materials.