An orderly arranged dual-role MIL-53(Al) nanorods array rooted on carbon nanotube film for long-life and stable lithium-sulfur batteries

It is of great value to synchronously resolve the critical issues of the polysulfide shuttle and dendrite growth in lithium-sulfur (Li-S) batteries. Herein, a bifunctional Al-based Material of Institute Lavoisier-53 (MIL-53(Al))/carbon nanotube (MIL-53/CNT) composite is reported for this matter, which was constructed by growing an ordered MIL-53(Al) nanorods array on the CNT film. For the sulfur cathode, the proposed structure serves as a multifunctional interlayer to block polysulfides and accelerate their catalytic conversion, thus efficaciously inhibiting the shuttle effect. Meanwhile, when applied as the anode host material (Li@MIL-53/CNT), the flexible CNT film serves as a self-standing framework to accommodate Li metal and alleviate the volume expansion, while the uniform ion channels built by the MIL-53(Al) nanorods array along with the abundant oxygen groups can homogenize Li ion diffusion, enabling a steady Li plating/stripping behavior and limiting the dendrite growth. Not surprisingly, Li-S full battery with MIL-53/CNT interlayer and Li@MIL-53/CNT anode delivers an appreciable specific capacity of 735 mAh·g−1 and excellent cycle durability at 5 C, presenting a limited capacity decay of 0.03% per cycle in 500 cycles. Besides, an impressive cycle stability and rate capability are also achieved at high-sulfur loading and lean electrolyte conditions.