A water-stable, light-weight, MOF-based membrane for mitigating polysulfide shuttling in Li-S batteries

Li-S batteries are considered as promising energy storage devices for future applications due to their high theoretical energy density. The "shuttle effect" is a fundamental problem that limits practical Li-S battery performance and impedes their commercial viability. In this work, we report a water-stable, light-weight, MOF-based interlayer for a Li-S battery as a highly efficient polysulfide barrier. The main component of this interlayer is a water-stable Co-based MOF, which can immobilize soluble polysulfides via abundant metal (Co) ions and heteroatoms (N, O), and promote sulfur redox reaction kinetics, leading to a significantly alleviated "shuttle effect". Remarkable electrochemical performance of the Li-S cell was maintained even at an ultralow loading of the interlayer (0.08 mg cm^-2). This study offers guidance for future design of MOF-based interlayers for enhanced Li-S battery performance.