Enhanced performance and electrocatalytic kinetics on porous carbon-coated SnS microflowers as efficient Li–S battery cathodes

Abstract

Effectively adsorbing and suppressing the polysulfide shuttle by polar materials are of great importance in lithium-sulfur (Li–S) batteries. Herein, the multifunctional SnS@C MS heterostructure consisting of porous carbon shell and SnS microflower-like core is prepared and demonstrated as an efficient Li–S battery cathode with electrocatalytic activity. The integrated physical confinement, strong chemical interaction, and rapid polysulfides (LiPSs) conversion kinetics are mutually promoted to facilitate a successive LiPSs adsorption-conversion with a significantly suppressed shuttle effect. Notably, systematic investigations and experiments reveal that the porous carbon layer can strongly entrap the LiPSs and subsequently facilitate its conversion kinetics between the liquid and solid phases. As a result, SnS@C/S MS cathode can deliver a high initial capacity of 1074.7 mAh g−1 at 0.1 C and ultra-stable cycling performance with a slow capacity decay rate of 0.073% per cycle over 600 cycles at 0.5 C. Moreover, the excellent durability with higher S loading and current densities are also achieved. Thus, this work proffers a facile and promising approach to design and prepare efficient Li–S battery cathodes with high reversible capacities and excellent cycle performance.