Lithium phosphate incorporated carbon nanotube interlayer as an efficient polysulfide immobilizer for high performance lithium sulfur batteries

Abstract

Lithium-sulfur (Li-S) batteries are the potential alternative for the lithium-ion batteries, owing to their remarkable energy density and specific capacity. Nevertheless, the lower utilization of active materials and the “shuttle effect” have impeded their widespread commercialization. To address these hurdles, a pioneering method has been proposed, involving a lithium phosphate-incorporated multi-walled carbon nanotube (Li3PO4@MWCNT) interlayer. The Li3PO4@MWCNT interlayer primarily serves as a physical barrier against polysulfide shuttling. Its highly conductive cross-link structure enables it to adsorb chemically derived lithium polysulfides (LiPS) and catalyze their conversion by incorporating Li3PO4 into the MWCNT matrix. This synergistic effect of immobilizing and converting LiPS results in a significant reduction in the “shuttle effect,” leading to enhanced sulfur utilization. The experimental results evidence the enhanced performance of the Li-S cells, with a capacity of 381 mAh g−1 at 0.1C and high C-rate performance of 393 mAh g−1 at 1C.

Keywords

• Li-S battery
• MWCNT
• Polysulfide immobilizer
• Lithium phosphate
• Catalytic effect
• Phosphorous interlayer