Fast and Facile Preparation of S Nanoparticle by Flash Nanoprecipitation for Lithium-sulfur Battery
This work demonstrates scalable and continuous flow production of sulfur nanoparticles (SNPs) using a confined impingement jet mixer (CIJ). Sizes and morphology of SNPs can be easily controlled by varying micro-mixing degree. Using high feed speed equal to 110 mL/min, spherical composites containing SNPs covered with polyvinylpyrrolidone (S@PVP) with uniform morphology and average diameter (485 nm) were obtained. These composites were tested as active cathode materials for Li-S batteries. Cathodes containing S@PVP composites exhibited high initial capacity equal to 1030.7 mA h/g. After 50 cycles at C/10, capacity was 807.7 mA h/g. Such excellent capacity and capacity retention were attributed to small size and homogeneous dispersion of SNPs as well as conducting PVP layer, which provided effective multidimensional electron and ion transport pathways. PVP layer also mitigated problem associated with volume expansion typically occurring during battery cycling. Simplicity and scalability of the method proposed in this work give it a very strong potential for large-scale continuous fabrication of SNPs for Li-S rechargeable batteries.