Curbing polysulfide shuttling by synergistic engineering layer composed of supported Sn4P3 nanodots electrocatalyst in lithium-sulfur batteries

Abstract The shuttle effect in lithium-sulfur (Li-S) batteries mainly originates from the diffusion of soluble polysulfides (LiPSs) and their depressed redox kinetics. Herein, we report a synergistic engineering layer composed of acorn shell porous carbon/Sn4P3 nanodots electrocatalyst (AS PC-Sn4P3). The synergistic engineering layer can not only serve as a conductive interface but also provide a dual-adsorption barrier to retain active material and inhibit the LiPSs migrating. More importantly, electrocatalytic Sn4P3 nanodots supported on acorn shell porous carbon (AS PC) within synergistic engineering layer effectively promote lithium ion diffusion, LiPSs conversion, Li2S2/Li2S deposition, and accelerate the electrochemical redox reaction and therefore curb the soluble LiPSs shutting behavior. As a result, enhanced Li–S battery performance is achieved with synergistic engineering layer, e.g., excellent cycling stability over 900 cycles at 1.0 C with a low capacity decay of 0.046% per cycle, a good rate performance, and a high areal capacity of 8.7 mAh cm−2 under lean electrolyte conditions.