Spatial Confinement Design with Metal-Doped Catalysts: Modulating Electronic-State of Active Sites for Accelerating Sulfur Redox Kinetics in Lithium-Sulfur Batteries

Abstract

The rational and well-structured construction of electrocatalysts with exceptional catalytic activity and adsorption capability is essential for effectively addressing the challenges faced by lithium-sulfur batteries (LSBs). In this paper, the synergistic effect of spatial confinement design and doping engineering-induced electronic-state modulation is leveraged to suppress the shuttle effect, and high-efficiency catalysis for polysulfide conversion is achieved. The Ni-doped CoSe₂ nanoparticles are in situ formed on a 3D MXene hollow microsphere via self-assembly and selenization strategies. The hollow structure provides spatial confinement and serves as a physical barrier, mitigating the polysulfide shuttle while the prevention of MXene self-stacking ensures maximal exposure of the Ni-CoSe₂ nanoparticles to provide additional active sites and enhances their adsorption properties. These findings are corroborated by electrochemical experiments and in situ XRD analysis, demonstrating significantly improved rate capabilities and cycling stability of LSBs utilizing the functional electrocatalyst. This study presents a valuable pathway for exploiting the synergistic effect of structural construction and electronic-state modulation to develop high-performance LSBs.