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

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  g S - 1after 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.