Core-shell titanium nitride/silicon nitride modified separators as polysulfide shuttling barriers for lithium-sulfur batteries via a facile and recyclable molten-salt route

Abstract

Lithium–Sulfur battery is deemed as one of the most promising next-generation energy storage systems. Identifying the reduction of soluble lithium polysulfides (LiPSs) is critical for rational material designs for Lithium–Sulfur batteries. In this work, a simple molten-salt method is applied to synthesize titanium nitride/silicon nitride (TiN–Si3N4) core-shell nanoparticles to inhibit soluble polysulfides shuttling. This Ti-reacted strategy has outstanding advantages such as facile and recyclable preparation process, tunable TiN morphology, and good polysulfide adsorption. With the modified separator, Li–S cells exhibit an outstanding initial capacity of 1243 mA h g−1 at 0.5C, good rate capacity of 782 mA h g−1 at 2C, and high capacity retention of 49.2% after 500 cycles. This low-cost and eco-friendly Ti-reacted strategy provides a practical route for the actual application of separator modification in the field of lithium-sulfur battery.