An overview of MOF-based separators for lithium-sulfur batteries

Lithium‑sulfur battery (LSB) is considered one of the most promising candidates among the next-generation rechargeable batteries due to its high specific energy and low cost. However, the increase of energy density and cycling performance of LSB is still hindered by the shuttle effect. One promising solution towards suppressing the shuttle effect is the functionalization of the separator within the LSBs. A functional separator can improve overall LSB performance by impeding the shuttle effect while increasing reaction kinetics, improving ionic/electrical conductivity, and inhibiting Li dendrite growth. In this review, we mainly focus on the use of metal-organic frameworks (MOFs) to functionalize separators. This paper includes recent examples of MOF-based separators for LSB, an analysis of the mechanisms which allow MOF-based separators to improve LSB performance, key considerations for the industrial scale-up of MOF synthesis, and several research recommendations based on the above. The goal of this review is to offer a perspective on MOF-based separators and help future researchers rationally design a functional separator towards commercially viable LSB.