ZnS Spheres Wrapped by Ultrathin Wrinkled Carbon film as Multifunctional Interlayer for Long-life Li-S Batteries
The shuttling of soluble lithium polysulfides (LiPSs) in Li-S batteries during cycling process is considered as a serious problem to handle. It often brings about sluggish redox kinetic, rapid capacity decay and limited sulfur utilization. In this study, we fabricate a novel functional interlayer by wrapping the dispersed zinc sulfide (ZnS) nanospheres with a graphene-like ultrathin wrinkled carbon film (ZnS@WCF) through a facile hard-template method. WCF acts as a unique 3D conductive network and ZnS nanospheres provide strong chemisorption to LiPSs. Owing to the synergetic effects between polar ZnS and conductive WCF, the as prepared interlayer not only can serve as a physical barrier but also can recycle the dissolved LiPSs with a fast reaction kinetic. Li-S batteries based on such ZnS@WCF modified separator exhibits remarkable capacity retention and outstanding rate performance. When cycling at 1 C, a considerable specific capacity of 685 mAh·g-1 can still be maintained after 600 cycles with an extremely low fading decay of 0.045 % per cycle. This novel interlayer holds great potential in realizing the wide practical application of Li-S batteries.