Cerium-Based MOF as a Separator Coating for High-Performance Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries are among the most promising batteries due to their high theoretical energy density (2600 Wh kg −1 ), low cost, and non-toxicity. However, many challenges need to be addressed for their practical applications, particularly the “shuttle effect.” Here, we successfully synthesized a composite of Ce-UiO-66-NH 2 (Ce-MOF) and designed a multifunctional separator coating for high-performance Li-S batteries. The physical barrier and the strong interaction between polysulfides and the metal sites in Ce-MOF in the Ce-MOF-based separator coating can inhibit the “shuttle effect.” The battery with Ce-MOF-based separator coating delivered a high initial capacity of 1366.3 mAh g −1 with good cycling stability and high Coulombic efficiency (CE) at 0.2 C (1 C = 1675 mA g −1 ). Furthermore, the Li-S batteries with Ce-MOF-based separator coating demonstrate superior retention capacity (0.09% decay rate per cycle, 300 cycles at 1 C) with a high sulfur loading of 3.5 mg cm −2 . Our results showed that Ce-MOF could be a promising material for enhancing the performance of Li-S batteries.