초록 |
Silicon is the most promising anode active material with high theoretical specific capacity. However, during the charging process, silicon suffers from its excessive volume expansion and shrinkage resulting in pulverization of the particles. Therefore, a protective layer on the silicon particle surface can mitigate the volume change and bring enhanced cell performance. Here, we propose silicon nanoparticles coated with ultra-thin cross-linked polyacrylonitrile layer (x-PAN) prepared by emulsion-assited method. In the previous report, we introduced ultra-thin polyacrylonitrile with stable cycling performance. A nanometer-thick polymer layer compensates the mechanical stress of silicon particles enhancing the long-term cyclability, without hindering ion and electron transportation. Nonetheless, after the wetting of the electrolyte, the mechanical property was lowered due to the polar solvents. X-PAN maintained the mechanical property even with a wetted state and allowed sustainable polymer layer leading to superior capacity retention after cycling. |