Inhibiting polysulfide shuttle and enhancing polysulfide redox: Conductive 2D metal-organic framework coated separators for lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have emerged as promising candidates for next-generation energy storage systems due to their high energy density and cost-effectiveness. However, their practical application faces several challenges, mainly the shuttle effect of lithium polysulfides (LiPSs). This effect implies the movement of dissolved LiPSs between the cathode and anode, leading to poor cycling stability and reduced energy efficiency. To overcome this issue, we present a novel approach involving the integration of a conductive 2D nickel hexahydroxytriphenylene (Ni-HHTP) metal-organic framework (MOF) and a carbon black of Super P (SP) onto a commonly used polyethylene (PE) separator. This functional composite coating facilitates efficient chemical adsorption and reutilization of LiPSs, resulting in improved cycling performance and enhanced stability. Significantly, the Ni-HHTP@SP coated separator demonstrates excellent discharge capacity, reaching 813 mAh g⁻¹ at a rate of 335 mA g⁻¹ (0.2 C, 1 C = 1675 mA g⁻¹) even after 100 cycles. These results underscore the effectiveness of the Ni-HHTP@SP coated separators in enhancing the performance and stability of Li-S batteries, offering valuable insights for practical implementation in energy storage applications.