ZnS spheres wrapped by an ultrathin wrinkled carbon film as a multifunctional interlayer for long-life Li–S batteries†
The shuttling of soluble lithium polysulfides (LiPSs) in Li–S batteries during the cycling process is considered as a serious problem to handle. It often brings about sluggish redox kinetics, rapid capacity decay and limited sulfur utilization. In this study, we fabricate a novel functional interlayer by wrapping dispersed zinc sulfide (ZnS) nanospheres with a graphene-like ultrathin wrinkled carbon film (ZnS@WCF) through a facile hard-template method. The WCF acts as a unique 3D conductive network and ZnS nanospheres provide strong chemisorption of LiPSs. Owing to the synergistic effects between polar ZnS and the conductive WCF, the as-prepared interlayer can not only serve as a physical barrier but can also recycle the dissolved LiPSs with fast reaction kinetics. Li–S batteries based on such a ZnS@WCF modified separator exhibit remarkable capacity retention and outstanding rate performance. When cycling at 1C, a considerable specific capacity of 685 mA h 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.