Regulate transportation of ions and polysulfides in all-solid-state Li-S batteries using ordered-MOF composite solid electrolyte.

Abstract

A dilemma arises when striving to balance the maximum desired ion conductivity and minimize the undesired lithium polysulfide shuttling effect for all-solid-state lithium-sulfur batteries (ASSLSBs). Here, we introduce a strategy of using ordered MIL-125-NH2 as fillers for poly(ethylene oxide)-based electrolytes to simultaneously regulate the transportation of lithium ions and polysulfides. When compared to electrolytes lacking metal-organic frameworks (MOFs) and those containing disordered MOFs, the electrolyte featuring an ordered-MOF structure, denoted as three-dimensional (3D) MPPL composite solid electrolyte (CSE), exhibits the highest ion conductivity of 8.3 × 10-4 siemens per centimeter at 60°C. As a result, pouch-type ASSLSBs with 3D MPPL CSE maintains stable cycling for 400 cycles at 0.5 C at 60°C, showcasing the successful implementation of this strategy in simultaneously regulating ion and polysulfide transport. This approach opens up alternative avenues to achieve high-performance ASSLSBs with exceptional energy density.