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 storage systems.However,the practical viability of Li-S batteries is largely hampered by undesirable shuttling behavior and sluggish conversion kinetics of polysulfides.Herein,a multifunctional separatormodified layer(In/Zr-BTB nanosheets)with the merits of robust structures and efficient catalytic metal sites has been presented.In/Zr-BTB nanosheets inherit the stable structure from Zr-BTB and strengthen the catalytic performance due to the introduction of highly catalytic species indium via metal-ion exchange.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 structures,and uniform pore channels can realize fast Li+transport,effective polysulfide interception,and rapid 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.