NiCo 2 O 4 @Porous Graphene Aerogel: Synergistic Adsorption-Catalysis for Enhancing Polysulfide Conversion

Combining transition metal oxides with polarity and three-dimensional porous carbon materials to leverage their synergistic effects is a strategy for addressing the challenges in commercializing lithium-sulfur batteries (LSBs). In this work, in order to accelerate the catalytic conversion of polysulfides, the cogrowth strategy is proposed, in which transition metal spinel oxide NiCo₂O₄ (NCO) is anchored on the surface of the reduced graphene oxide aerogel (rGA) to form hierarchical NiCo₂O₄@rGA, simultaneously altering the loading amount of NiCo₂O₄ to investigate the influence of its content on cyclic performance. The results show that the specific surface area of NCO@rGA-13 is 226 m² g^-1, which is higher than that of rGA (133 m² g^-1), indicating that the addition of NCO can increase the sites of adsorption and reaction. Besides, it has been found that the NCO@rGA-13/S cathode delivers an initial discharge specific capacity of 1112 mAh g^-1 at 1 C, keeping a capacity of 722 mAh g^-1 after 500 cycles. In situ UV-vis spectroscopy confirms that the concentration of S₃^.- for NCO@rGA-13 is higher than that for rGA, indicating that NCO@rGA-13 can accelerate the conversion of polysulfides. Therefore, this work presents an efficient strategy to simultaneously achieve dual adsorption and catalytic conversion of polysulfides, which is conducive to facilitating the industrialization of LSBs.