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

Abstract 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.