Synthesis of double-layered hollow carbon spheres with large interlayer space as sulfur hosts for Li-S batteries

Double-layered hollow carbon spheres (DLHC) were widely used as sulfur matrix for Li-S batteries. However, DLHC with 20-30 nm interlayer distances between carbon shells were reported due to the difficult controllable synthesis of monodisperse silica template (< 200 nm) in the Stober method, leading to low sulfur utilization. Here, DLHC with the interlayer space up to 50 nm (DLHC-50) is synthesized by controlling hydrolysis rate of tetraethyl orthosilicate (TEOS) using ammonia/LiOH as catalysts. DLHC-50 based sulfur cathode contains high sulfur content of 82%, and exhibits excellent cycling and rate performances. This research provides guidance for synthesis of DLHC with high sulfur utilization