Gadolinium oxide nanorods decorated Ketjen black@sulfur composites as functional catalyzing polysulfides conversion in lithium/sulfur batteries

摘要

The development of lithium/sulfur batteries (LSBs) was hindered due to the shuttling of lithium polysulfides in electrolytes and sluggish electrochemical kinetics of polysulfides. To address these stumbling blocks, we designed gadolinium oxide (Gd_2O_3) nanorods decoration of ketjen black@sulfur (Gd_2O_3/ KB@S) composite that adsorbs and provides sufficient sites with lithium polysulfides interaction. The Gd_2O_3 nanorods play a key role in the adsorption and catalysis performance of polysulfides, which further accelerate the redox kinetics. Consequently, the Gd_2O_3/LB@S cathode with sulfur loading of 3.1 mg cm~(-2) attained a high initial discharge capacity of 817.2 mAh g~(-1) at 0.5 C with a decaying rate of 0.097 per cycle over 500 cycles. Even with high sulfur loading of 5 mg cm~(-2), the Gd_2O_3/KB@S cathode also presents a capacity of 5.1 mAh at 0.2 C with retention of 73 over 160 cycles. The strategy proposed here would advance the development of continuous rare earth oxides in the field of rechargeable batteries.