Unraveling the Mechanisms of Zirconium Metal-Organic Frameworks-Based Mixed-Matrix Membranes Preventing Polysulfide Shuttling

Abstract

Lithium-sulfur batteries are considered as promising candidates for next-generation energy storage devices for grid applications due to their high theoretical energy density. However, the inevitable shuttle effect of lithium polysulfides and/or dendrite growth of Li metal anodes hinder their commercial viability. Herein, the microporous Zr fumarate metal-organic framework (MOF)-801(Zr) is considered to produce thin (approximate to 15.6 mu m, approximate to 1 mg cm2) mixed-matrix membranes (MMM) as a novel interlayer for Li-S batteries. It is found that the MOF-801(Zr)/C/PVDF-HFP composite interlayer facilitates Li+ ions diffusion, and anchors polysulfides while promoting their redox conversion effectively. It is demonstrated that MOF-801 effectively trapped polysulfides at the cathode side, and confirmed for the first time the nature of the interaction between the adsorbed polysulfides and the host framework, through a combination of solid-state nuclear magnetic resonance and molecular dynamics simulations. The incorporation of MOF-801(Zr)/C/PVDF-HFP MMM interlayer results in a notable enhancement in the initial capacity of Li-S batteries up to 1110 mA h g-1. Moreover, even after 50 cycles, a specific capacity of 880 mA h g-1 is delivered. Microporous metal-organic frameworks-801(Zr) is a model to decipher the nature of the interaction between the adsorbed polysulfides and the host framework, through a combination of solid-state nuclear magnetic resonance and molecular dynamics simulations and its shaping in mixed-matrix membranes as a novel interlayer material for lithium-sulfur batteries.image (c) 2024 WILEY-VCH GmbH