Promoting polysulfide adsorption and conversion via heterostructured MnO(1-x)-Mn3O4 in a carbon-based interlayer for high performance Li-S batteries

Lithium-sulfur (Li-S) batteries hold great promise as next-generation energy storage devices due to their high theoretical energy density, cost-effectiveness, and environmental friendliness. However, their practical implementation is hindered by challenges such as the shuttle effect of lithium polysulfides (LiPSs) and sluggish redox kinetics. Herein, a novel MnO(1-x)-Mn3O4/C@CC composite interlayer has been designed and synthesized via a two-step carbonization process. The composite synergistically integrates MnO(1-x)-Mn3O4 with defect-rich structures in porous carbon matrix, which enhances the adsorption and catalytic conversion of LiPSs. The Li-S batteries with MnO(1-x)-Mn3O4/C@CC achieve a high initial discharge capacity of 1050 mAh g−1 at 0.2C and retain 845 mAh g−1 after 100 cycles, corresponding to a capacity retention of 80.5 %. Furthermore, they exhibit superior rate capability and reduced charge transfer resistance. This study provides new insights into the development of high-performance interlayer materials, paving the way for practical Li-S battery applications.