Sulfur-Composites Derived from Poly(acrylonitrile) and Poly(vinylacetylene) - A Comparative Study on the Role of Pyridinic and Thioamidic Nitrogen

Sulfurized poly(acrylonitrile) (SPAN) is a prominent example of a highly cycle stable and rate capable sulfur/polymer composite, which is solely based on covalently bound sulfur. However, so far no in-depth study on the influence of nitrogen in the carbonaceous backbone, to which sulfur in the form of thioketones and poly(sulfides) is attached, exists. Herein, we investigated the role of nitrogen by comparing sulfur/polymer composites derived from nitrogen-containing poly(acrylonitrile) (PAN) and nitrogen-free poly(vinylacetylene) (PVac). Results strongly indicate the importance of a nitrogen-rich, aromatic carbon backbone to ensure full addressability of the polymer-bound sulfur and its reversible binding to the aromatic backbone, even at high current rates. This study also presents key structures, which are crucial for highly cycle and rate stable S-composites.