Enhancement of Lithium-Sulfur Batteries By Introducing Metal-Organic-Framework (MOF) Coated Separators

Sulfur has received high attention as an advanced cathode material due to the advantages of its high theoretical energy density of 2600Wh/kg, environmental friendliness, and cost-benefit. Despite of its many strong points in lithium sulfur batteries, it is not sufficient to practically use the sulfur cathode in commercial lithium-ion batteries due to the active material loss and the polysulfides shuttling effect. To address the above-mentioned challenges, two main approaches have been intensively investigated: a) Control of dissolved polysulfide intermediates in electrolyte by designing scaffolds of sulfur or electrolytes. b) Confinement of polysulfides within the sulfur cathode side by introducing an additional interlayer in-between sulfur cathode and separator. However, there are few approaches on a separator only to prevent the migration of sulfur species to the anode for electrochemically stable lithium sulfur batteries. Here, we suggest inserting metal-organic-framework (MOF) coated separator by using simple surface modifying strategy with polydopamine (PDA). MOF has interesting properties such as high porosity, chemical absorption and catalytic property. MOF coated separator effectively retards the diffusion of polysulfides to counter electrode due to its physicochemical sorption property. The sulfur battery with MOF coated separator shows an improved cycle performance and high specific capacity, compared to pristine separator. Figure 1