Polyaniline: an effective suppressor against diffusion and dissolution of polysulfides in Li-S battery

To suppress the notorious shuttle effect and capacity fading in lithium-sulfur battery, polyanilinehas been introduced due to its multi-anchoring sites for polysulfides, but high content of polyanilineis inevitably accompanied by increase in the inactive content of total cathode and sacrifice in the energy density. Here we disclose that extremely low polyanilineloading can realize excellent cell performance, where conductive polyanilineis uniformly produced on the surface of sulfur-wrapped carbon nanoparticles via dilute aniline polymerization. Even ca. 1 wt% of polyanilineloading is enough to suppress diffusion and dissolution of polysulfides, and the sluggish charge transfer is accelerated. In addition to enhanced cycle stability, a remarkable increase in capacity by ca. 46% is realized compared to sulfur-wrapped carbon composite after 100th at 0.5 C. Moreover, an electrochemical property with coulombic efficiency above 95% and a high capacity retention rateof 55% is achieved even after 500 cycles at ca. 2 wt% polyanilineloading.