Oligoanilines as a suppressor of polysulfide shuttling in lithium-sulfur batteries

The migration of small polysulfide (LiPS) chains through the porous polymeric separators seriously jeopardizes the cycle life and energy density of lithium-sulfur (Li-S) batteries. Herein, we present a new concept in which an organic oligoaniline, amine-capped aniline trimer (ACAT), serves as an effective suppressor of the LiPS migration in Li-S cells. The strong interaction between LiPS and ACAT facilitates the formation of bulky ACAT-LiPS complexes (organoLiPS complexes), which are then size-selectively sieved by the porous polymeric separators employed in Li-S cells. Thus, the addition of ACAT significantly ameliorates the electrochemical performances of Li-S batteries due to suppressed LiPS migration. This new concept offers a viable strategy to achieve practically viable Li-S batteries.