Conductive MOF-Modified Separator for Mitigating the Shuttle Effect of Lithium–Sulfur Battery through a Filtration Method

Abstract

Although there are plenty of merits for lithium–sulfur (Li–S) batteries, their undesired shuttle effect and insulated nature are hindering the practical applications. Here, a conductive metal–organic framework (MOF)-modified separator has been designed and fabricated through a facile filtration method to address the issues. Specifically, its intrinsic microporous structure, hydrophilic polar property, and conductive feature could make it easy to contact with and trap polysulfides and boost the kinetics of electrochemical reactions. Both the physical and chemical properties of the as-prepared separator are beneficial to alleviating the shuttle effect and enhancing the rate capability. Accordingly, the electrochemical performance of the battery with a MOF-modified separator was significantly improved.

Recent advances in interlayer and separator engineering for lithium-sulfur batteries

“…For example, Chen's group adopted a new MOF structure, Ni 3 (2,3,6,7,10,11-hexaiminotriphenylene) 2 (Ni 3 (HITP) 2 ) to modify PP separator for trapping polysulfide. The MOF was fabricated by adding concentrated NH 4 OH to NiCl 2 and 2,3,6,7,10,11-hexaamino triphenylene hexahydrochloride (HATPÁ6HCl) aqueous solution, followed by continuous stirring and low-temperature heating [124]. The metal center of MOF enhanced the affinity to polysulfide due to the Lewis acid-base interaction, and the resultant MOF-based coating interlayer showed an intrinsic microporous structure with hydrophilic polarity and high conductivity that significantly boosted the kinetics of the electrochemical reaction in the cell.…”

The Role of Defects in Metal–Organic Frameworks for Nitrogen Reduction Reaction: When Defects Switch to Features

“…MOFs, a family of crystalline porous material assembled by multiform organic linkers and metal ions/clusters, have shown an enormous impact on Li‐ion batteries, [ 145 ] supercapacitors, [ 146 ] and energy‐conversion electrochemical reactions. [ 147–149 ] Recently, the synthesis of MOFs and their derivatives for electrochemical applications has been considered as a promising research area due to their intriguing characters of diverse structures, large surface area, and high porosity.…”

Recent Progress of Nanoscale Metal‐Organic Frameworks in Synthesis and Battery Applications

“…[ 128 ] Additionally, other NMOFs such as sulfonated UiO‐66, Cu‐TCPP nanosheets (TCPP = 5,10,15,20‐tetrakis(4‐carboxyphenyl) porphyrin), conductive Ni 3 (HITP) 2 (HITP = 2,3,6,7,10,11‐hexaiminotriphenylene), and Ce‐MOF (350 nm) have also been applied in LSBs as separators and have enhanced the capacity retention and cycling stability. [ 129–132 ] Recently, Kim et al. coated multi‐walled carbon nanotubes with small Ni‐based MOF particles onto a polyethylene separator to increase the discharge capacity and cycling stability.…”