Yttrium oxide nanorods as electrocatalytic polysulfides traps for curbing shuttle effect in lithium-sulfur batteries

Abstract

Although lithium-sulfur (Li-S) batteries have high theoretical specific capacity, their development is limited by low reaction kinetics during solid-liquid conversion of polysulfides and severe dissolution of polysulfides leading in loss of active materials and the corrosion of Li metal. In this paper, a novel electrode material which synthesized by yttrium oxide (Y2O3) nanorods modified Ketjen black@sulfur (Y2O3/KB@S) composites is introduced and evaluated in Li-S batteries. Y2O3 nanorods have good adsorption-catalytic synergistic effect on polysulfides, which can curb the shuttle effect and enhance the redox kinetics of polysulfides. The initial specific discharge capacity of Y2O3/KB@S electrode shows 828 mAh g−1 at 0.5 C current density, and the capacity maintains at 388 mAh g−1 after 500 cycles with the areal sulfur loading of 3.1 mg cm−2. Furthermore, Y2O3/KB@S cathode delivered 5.09 mAh discharge capacity and retained 4.21 mAh after 100 cycles at 0.2 C current density when the areal sulfur loading increasing to 5.0 mg cm−2. Therefore, Y2O3 nanorods modified Li-S battery cathode material has good application potential in its industrialization process.