Green Upcycling Lithium Tailings into a Multifunctional Separator for Lithium–Sulfur Batteries

Lithium-sulfur (Li-S) battery is recognized as one of the most promising energy storage devices. Nevertheless, the development of Li-S battery is plagued by the fatal shuttle effect of soluble lithium polysulfides (LiPSs) and sluggish reaction kinetics. Herein, the lithium tailing containing zinnwaldite activated after mechanochemical process is introduced to modify separators of Li-S battery for the first time. The activated zinnwaldite-containing lithium tailings (ALZT) consist of quartz, K-feldspar, kaolinite, and zinnwaldite. It not only possesses rich polar active sites such as Si, Al, Fe, and O ions to immobilize LiPSs but also contains higher Fe³ ⁺ content than zinnwaldite-containing lithium tailings (LZT), which significantly accelerates the redox kinetics of LiPSs. A novel composite PP separator modified by ALZT combined with conductive carbon black (ALZT@Super P@PP) has been prepared for Li-S battery. ALZT@Super P@PP separator not only shows superior electrolyte affinity, faster electrolyte wetting speeds, higher lithium-ion transference number, and ionic conductivity but also effectively enhances the LiPS trapping ability and significantly accelerates the transformation kinetics of LiPSs. Remarkably, Li-S batteries with ALZT@Super P@PP exhibit superior rate performance. The green protocol reported here paves the way for utilizing tailings in Li-S battery applications, enabling green uprecycling of mining waste.