Electrochemical Properties of Sulfurized-Polyacrylonitrile Cathode for Lithium–Sulfur Batteries: Effect of Polyacrylic Acid Binder and Fluoroethylene Carbonate Additive

Sulfurized carbonized polyacrylonitrile (S-CPAN) is a promising cathode material for Li–S batteries owing to the absence of polysulfide dissolution phenomena in the electrolyte solutions and thus the lack of a detrimental shuttle mechanism. However, challenges remain in achieving high performance at practical loading because of large volume expansion of S-CPAN electrodes and lithium anode degradation at high current densities. To mitigate this problem, we propose a novel cell design including poly­(acrylic acid) (PAA) binder for improved integrity of the composite electrodes and fluoroethylene carbonate (FEC) as additive in the electrolyte solutions for stabilizing the lithium metal surface. As a result, these cells delivered high initial discharge capacity of 1500 mAh g–1 and a superior cycling stability ∼98.5% capacity retention after 100 cycles, 0.5 C rate, and high sulfur loading of 3.0 mg cm–2. Scaled-up 260 mAh pouch cells are working very well, highlighting the practical importance of this work.