Stepped Channels Integrated Lithium-Sulfur Separator via Photoinduced Multidimensional Fabrication of Metal-Organic Frameworks.

ABSTRACT

Multidimensional fabrication of metal-organic frameworks (MOFs) into multilevel channel integrated devices are in high demanded for Li-S separators. Such separators have advantages in pore-engineering that might fulfill requirements such as intercepting the diffusing polysulfides and improving the Li+ /electrolyte transfer in Li-S batteries. However, most reported works focus on the roles of MOFs as ionic sieves for polysulfides while offering limited investigation on the tuning of Li+ transfer across the separators. A photoinduced heat-assisted processing strategy is proposed to fabricate MOFs into multidimensional devices (e.g., hollow/Janus fibers, double-or triple-layer membranes). For the first time, a triple-layer separator with stepped-channels has been designed and demonstrated as a powerful separator with outstanding specific capacity (1365.0 mAh g-1 ) and cycling performance (0.03 % fading per cycle from 100th to 700th cycle), which is superior to single/double-layer and commercial separators. The findings may expedite the development of MOF-based membranes and extend the scope of MOFs in energy-storage technologies.