Rice husks-derived hierarchical porous SiO2@C as efficient polysulfide mediator for Li-S batteries

The serious shuttle effect and sluggish redox kinetics hinder the practical implementation of Li-S batteries. Here, we proposed a general method for large-scale synthesis of hierarchical porous SiO2@C host derived from waste rice husks. The prepared SiO2@C-2.5S cathode exhibits superior electrochemical properties, which can be attributed to the physical adsorption of porous carbon shell and chemical anchoring effect of SiO2 nanoparticles. Moreover, the hierarchical porous carbon matrix provides a highly conductive channel for rapid electron and ion transport, and offers enough space for the volume expansion of elemental S during the reaction. (C) 2021 Elsevier B.V. All rights reserved.