Study of CNTs-MoS2/CeO2 composites for lithium-sulfur battery performance

In recent years, lithium-sulfur batteries have received a lot of attention because of their high energy density (2600 Wh kg−1) and theoretical specific capacity (1675 mAh g−1), but they also suffer from poor electrical conductivity of S and its final products Li2S (the room temperature electronic conductivity is 5 × 10−30 S cm−1 and 3.6 × 10−7 S cm−1, respectively), volume expansion of the sulfur cathode during the reaction, and the “shuttle effect” of the polysulfide generated by the reaction in the electrolyte need to be solved. In order to solve the above problems, this paper has successfully compounded carbon nanotubes (CNTs) with molybdenum disulfide (MoS2) and cerium dioxide (CeO2) nanomaterials by a simple hydrothermal method to prepare CNTs-MoS2/CeO2 nanocomposites, in which MoS2 catalyzes the conversion of long-chain polysulfides to short-chain polysulfides, and CeO2 can adsorb polysulfides and inhibit their dissolution, thus alleviating the “shuttle effect.” The experimental results show that the composites have excellent electrochemical performance, with a discharge capacity of 1373.4 mAh g−1 in the first cycle at a current density of 0.1 C, and a discharge capacity of 933.9 mAh g−1 after 200 cycles at a current density of 0.2 C. The Coulomb efficiency can reach over 99%.