3D porous carbon gel composite with transition metal particles for anchoring-diffusion-conversion of polysulfides for lithium–sulfur batteries

Lithium-sulfur batteries (LSBs) exhibit high energy density and high theoretical specific capacity, approximately one order of magnitude higher than traditional lithium-ion batteries. However, the shuttling effect of lithium polysulfides (LiPSs) generated during the charge-discharge process severely compromises battery performance and hinders commercialization. In this paper, a 3D porous carbon gel sulfur host, M@rGO–PCG (M=Ni, Co), composed of transition metal particles and redox graphene, was fabricated through gelation and freeze-drying techniques. This material enhances the conductivity of the cathode, buffers the volume expansion of the electrode, and further accelerates the catalytic conversion of LiPSs. The assembled Ni@rGO–PCG/S and Co@rGO–PCG/S batteries deliver initial discharge specific capacities of 1390.0 mA·h·g −1 and 1603.6 mA·h·g −1 at a current rate of 0.1 C, respectively. The findings provide valuable insights into the synergistic suppression of the shuttling effect through multiple functions. • M@rGO–PCG (M=Ni, Co) were prepared by gelation and freeze-drying and used as hosts for sulfur cathodes. • M@rGO–PCG (M=Ni, Co) inhibiting LiPSs shuttling via physical confinement, chemical adsorption and catalytic sulfur fixation. • M@rGO–PCG/S (M=Ni, Co) cathodes exhibit superior cycling stability.