Gadolinium oxide nanorods decorated Ketjen black@sulfur composites as functional catalyzing polysulfides conversion in lithium/sulfur batteries
Youqiang Wang, Heli Yu, Mingzhu Bi, Xiangqian Shen, Tianbao Li, Shibiao Qin, Shanshan Yao
Abstract
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 (Gd2O3) nanorods decoration of ketjen black@sulfur (Gd2O3/KB@S) composite that adsorbs and provides sufficient sites with lithium polysulfides interaction. The Gd2O3 nanorods play a key role in the adsorption and catalysis performance of polysulfides, which further accelerate the redox kinetics. Consequently, the Gd2O3/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 Gd2O3/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.