MnO-Mo2C heterogeneous particles supported on porous carbon: Accelerating the catalytic conversion of polysulfides

Poor conversion between sulfur and sulfur-related species and the dissolution of intermediates result in slow commercialization development. Herein, MnO-Mo2C heterogeneous particles supported on porous carbon (MnOMo2C/C) are synthesized using chitosan as a sulfur host for Li-S batteries. MnO-Mo2C heterogeneous particles possess superior calculated binding energies for sulfur redox and Fermi energy levels compared with single MnO and Mo2C, which suggests that MnO-Mo2C leads to a fast conversion of polysulfides and accelerates electron transport. In addition, in situ X-ray diffraction and Raman spectra measurements reveal mixed mechanisms of polysulfide conversion on MnO-Mo2C/C, wherein Li2S6 undergoes LiS3 and Li2S4 reduction reaction paths. The MnO-Mo2C/C@S cathode exhibits a high discharge specific capacity (929.6 mAh/g) and ultra-low decay rate of 0.019 % at 2C for 1200 cycles. Even at a sulfur loading of 8.0 mg cm (2), the MnO-Mo2C/C@S cathode exhibits a high reversible area capacity of 5.10 mAh cm(2).