Modified polysulfides conversion catalysis and confinement by employing La2O3 nanorods in high performance lithium-sulfur batteries

The development of lithium-sulfur batteries (LSB) was hindered due to the shuttling of Li-polysulfides in electrolytes and sluggish electrochemical kinetics of polysulfides. To address these stumbling blocks, we introduced La2O3 nanorods modification of ketjen black@sulfur (La2O3/KB@S) composite that adsorbs and provides sufficient sites with Li-polysufides interaction. The La2O3 nanorods play a key role in the adsorption and catalysis performance of the polysulfides, which further accelerate the redox kinetics. Consequently, the La2O3/KB@S cathode with sulfur loading of 3.1 mg cm(-2) attained a high initial discharge capacity of 833 mAh g(-1) at a 0.5C rate and displayed excellent cyclic stability with reversible capacity of 380 mAh g(-1) after 500 cycles with an average of 98% coulombic efficiency. Further, even with high sulfur loading of 5 mg cm(-2), the La2O3/KB@S cathode also presents a capacity of 4.9 mAh at 0.3C and still maintains a stable value of 3.87 mAh after 150 cycles. The results suggest the multifunction La2O3 nanorods anchoring effectively and catalyzing are beneficial to realize the goal of the large-scale application with high load active materials and high-performance LSB.

Automated summary

By introducing La2O3 nanorods modified Ketjen black@sulfur composite, the issues of Li-polysulfides shuttling and sluggish electrochemical kinetics in lithium-sulfur batteries are addressed, with La2O3 nanorods playing a key role in the adsorption and catalytic performance of polysulfides, accelerating the redox kinetics.