Metal–Organic Framework-Derived Magnesium Oxide@Carbon Interlayer for Stable Lithium–Sulfur Batteries

Lithium sulfur (Li–S) batteries represent a promising future battery technology. However, the low electrical conductivity of solid-state species (S, Li2S2, and Li2S) polysulfide shuttle effect deteriorate their practical capacity cycling retention. Herein, we present an interlayer composed magnesium oxide (MgO) nanoparticles carbon matrix for Li–S batteries. In composite, MgO can capture dissolved polysulfides that diffuse to along surface further reduction reactions. As novel precursor produce composite structure, Mg metal–organic-framework, Mg-MOF-74, is adopted synthesized on free-standing paper (MOF/C-paper). Through pyrolysis, Mg-MOF-74 converted into highly porous containing uniformly distributed (MgO@C/C-paper). The cells assembled with MgO@C/C-paper C-paper show significantly higher initial capacities (980 898 mAh g–1, respectively) than interlayer-free cell (729 g–1) owing conductive interlayers. After 200 cycles at 0.2 C, presents cycle retention (78.3%) superior (76.5%). With loading 3.3 mg cm–2, exhibits even (80.1%) (54.6%) after 100 cycles. excellent stability over demonstrates unique structure MOF-derived MgO@C effective in anchoring reutilizing polysulfides.