MOFs改性芳纶纳米纤维锂硫电池隔膜的制备

MOFs modified aramid nanofiber separator for lithium-sulfur batteries

锂硫电池由于高的理论容量和能量密度,且成本低廉,在未来储能领域具有广阔的应用前景。隔膜作为锂硫电池的重要组成部分,对电池的安全性起着至关重要的作用。通过在静电纺丝PMIA纳米纤维中掺杂ZIF-67二级纳米颗粒,制备ZIF-67改性的高安全性PMIA芳纶复合隔膜。二次纳米结构不仅为锂离子的扩散/迁移提供了高通量通道,还可以提供大的比表面积和丰富的金属活性位点,进一步抑制多硫化物的穿梭效应。掺杂的ZIF-67使得PMIA复合隔膜孔径更均匀,有利于锂负极的均匀成核和生长。由于PMIA材料的固有特性,改性的多功能复合隔膜也表现出高的热稳定性。因此,复合隔膜ZIF-67@PMIA作为锂硫电池的隔膜时,表现出优异的循环性能和倍率性能。

Lithium-sulfur(Li-S)batteries have broad application prospects in the future energy storage field due to their high theoretical capacity and energy density and low cost.The separator,as a critical component between the cathode and the anode,plays a vital role in the safety of batteries.A high safety PMIA aramid composite membrane modified by ZIF-67 is prepared by doping ZIF-67 secondary nanoparticles into PMIA nanofibers with electro spinning approach.The secondary nanostructures is not only beneficial to the high-flux lithium-ion transport and fast electrolyte diffusion/migration,but also can provide the large surface area and abundant metal active sites to facilitate the suppression of the Li2Sxshuttle effect.The doped ZIF-67 makes the pore size of PMIA composite diaphragm more uniform,which is conducive to the uniform nucleation and growth of lithium anode.Due to the inherent nature of the PMIA materials,the ZIF-67@PMIA separators exhibit excellent thermal stability.Hence,the ZIF-67@PMIA separator displayed high long-life cycle performance and excellent rate performance in Li-S batteries.