Encapsulating Antimony metal nanoparticles in hierarchical porous carbon skeleton as high-performance potassium- and lithium-ion batteries anodes

Metallic antimony (Sb) as alkaline metal battery anode material, being thoroughly researched for its high theoretical specific capacity, but there is still a huge expansion problem with repeated insertion/de-insertion., We reported a unique composite material that encapsulates Sb nanoparticles in hierarchical porous carbon skeletons (Sb@HPCs) in this work, to explore the effect of the hierarchical porous carbon structure on the electrochemical performance of the Sb@HPCs as potassium-ion batteries (KIBs) and lithium-ion batteries (LIBs) anode materials. The macropores could promote the penetration of electrolyte, thus reducing the internal impedance of the battery. The mesopores provide a short ion diffusion path and a large diffusion region, which plays a crucial role in facilitating rapid ionic migration in both KIBs and LIBs. The micropores in the electrode material contribute to a larger specific surface area, which provides more surface area for charge storage, thus enhancing the energy density of the material. Importantly, when the Sb@HPCs composite material is applied as anode material of KIBs, it exhibits an outstanding specific capacity of 360 mAh g-1 after 100 cycles at 100 mA g-1. In the LIBs, the specific capacity of the composite material is 595.2mAh g-1 after 100 cycles at a current density of 0.1 A g-1; even at a high current density of 1.0 A g-1, the specific capacity still maintains at 320.4 mAh g-1 after 800 cycles, indicating an excellent cycling stability. The development of hierarchical porous three-dimensional structure offers a practical solution to the capacity degradation issues of metal anode in KIBs/LIBs.