A carbon mixed amorphous-TiSx separator coating for lithium sulfur batteries

ABSTRACT Although lithium sulfur batteries have the advantage of high theoretical energy density and low cost, the problems arising from the polysulfide shutting and the Li metal dendrite remain challenging. Among all the solutions, separator coating is a compromise solution which can not only impede polysulfide shuttling but also suppress the Li dendrite growing. Herein, an amorphous-TiSx coating (ATSC) has been applied to the separator in the Li-S batteries. The TiSx works as a catalyst which could confine the polysulfides in the cathode side and facilitate the charge transfer process. In addition, the ATSC shows well conductivity which is well verified by the electrochemical analysis. Cycling performance of the Li-S cell reveals that the specific capacity of the cell with ATSC remains 1030 mAh g-1 at 0.1C after 50 cycles even without LiNO3 in the electrolyte. The superior electrochemical performance proves that applying ATSC is a promising method to improve the electrochemical performance in Li-S batteries.