Soft template synthesis of acetylene black/manganese dioxide nanosheets composites as efficient sulfur hosts for lithium–sulfur batteries

Manganese dioxide (MnO₂)-based nanomaterials can be used as sulfur host, improving the cycle stability by inhibiting the shuttle effects of polysulfide through chemisorption with the polar host. In this work, we design a novel soft template synthesis of acetylene black and MnO₂ nanosheets (AB/MnO₂) composites by simple and cost-effective methodology. The AB/MnO₂ was used as a highly efficient sulfur host for advanced lithium–sulfur batteries. The cheap and highly conductive AB facilitates fast electron transport. The polar host, MnO₂ nanosheets, provides chemical interactions and efficiently impedes the dissolution of polysulfide. Accordingly, the cathodes AB/MnO₂–S (4:1) and AB/MnO₂–S (1:1) with 67 and 70 wt% sulfur content deliver the initial discharge specific capacity of 1326 and 1113 mA h g⁻¹ at the current density of 837.5 mA g⁻¹ (0.5 C), respectively. Particularly, the AB/MnO₂–S (1:1) cathode shows the most stable coulombic efficiency and cyclability compared with AB/S cathode after 200 cycles. In addition, the AB/MnO₂–S (4:1) cathode exhibits a capacity of 1071 mA h g⁻¹ at the current density of 1675 mA g^–1 (1 C). Along with this green and cost-effective protocol of synthesis, we expect that the AB/MnO₂ composites have potential application in advanced Li–S batteries.