Robust In-Zr Metal-Organic Framework Nanosheets as Ultrathin Interlayer Toward High-Rate and Long-Cycle Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have great potential as the next generation of high-energy-density stor-age systems. However, the practical viability of Li-S batteries is largely hampered by undesirable shut-tling behavior and sluggish conversion kinetics of polysulfides. Herein, a multifunctional separator-modified layer (In/Zr-BTB nanosheets) with the mer-its of robust structures and efficient catalytic metal sites has been presented. In/Zr-BTB nanosheets in-herit the stable structure from Zr-BTB and strengthen the catalytic performance due to the introduction of highly catalytic species indium via metal-ion ex-change. The thickness and areal mass loading of the modified layer are only 260 nm and 0.011 mg/cm2, respectively. Nevertheless, the ultrathin modification layers with efficient catalytic species, compact struc-tures, and uniform pore channels can realize fast Li+ transport, effective polysulfide interception, and rap-id catalytic conversion. Therefore, the In/Zr-BTB@PP cell with a high sulfur content of 80 wt % could maintain high capacity retention of 85.6% with a low capacity fading rate of 0.048% per cycle after 300 cycles even at a high current rate of 2 C. This work opens a new door toward the design of versatile metal-organic framework (MOF) nanosheets and multifunctional separators for high-energy-density Li-S batteries.