Superfine SnO2–x Particles Embedded in a Porous Carbon Matrix as a Separator-Modifying Material for High-Performance Lithium Sulfur Batteries

The commercialization of lithium sulfur batteries faces great challenges, such as shuttle effect and low conductivity. Herein, we explore embedding anoxic oxide SnO2–x in a porous carbon matrix as a separator-modifying material for lithium sulfur batteries. This material can limit the size of SnO2–x particles and reduce their agglomeration through confining by the porous carbon (PC). As a result, more adsorption and catalytic sites can be obtained. Moreover, the oxygen vacancies in SnO2–x can change the electronic environment to enhance the adsorption and catalysis of polysulfides, resulting in the depression of the shuttle effect of the battery. Therefore, the lithium sulfur battery with the SnO2–x/PC-modified separator has excellent cycling performance. At a current rate of 1 C, it can provide a high initial discharge capacity of 1049.4 mAh g–1 and maintain a reversible specific capacity of 798.4 mAh g–1 after 300 cycles.