Synergetic Shielding Effect of a Silicon Nitride-Porous Carbon/Silicon Nitride-Modified Celgard Separator for Highly Stable Lithium-Sulfur Batteries

Abstract

The practical deployment of lithium-sulfur batteries (LSBs) is limited by the poor conductivity of sulfur and the diffusion of lithium polysulfides. To overcome these challenges, we present a multifunctional separator modified with silicon nitride (SiN) and high-surface-area porous carbon (PC, >2000 m(2)/g) coated on both sides of a polypropylene (PP) membrane. This dual-coated SiN-PC/SiN separator not only suppresses polysulfide shuttling but also enhances lithium-ion transport and catalytic conversion. The modified separator effectively stabilizes the lithium anode, reduces dendrite formation, and ensures uniform lithium plating/stripping. As a result, the LSBs demonstrate remarkable cycling stability with a specific capacity of similar to 600 mAh/g at 1.0C and a high sulfur loading (>3.5 mg/cm(2)) over 200 cycles. This design offers a promising strategy for improving both the cathode and anode interfaces, paving the way for high-performance LSBs.