FeS2 has drawn tremendous attention as electrode material for sodium-ion batteries (SIBs) due to its high theoretical capacity and abundant resources. However, it suffers from severe volume expansion and dull reaction kinetics during the cycling process, leading to poor rate capacity and short cyclability. Herein, a well-designed FeS2@C/G composite constructed by FeS2 nanoparticles embedded in porous carbon nanorods (FeS2@C) and covered by three-dimensional (3D) graphene is reported. FeS2 nanoparticles can shorten the Na+ diffusion distance during the sodiation-desodiation process. Porous carbon nanorods and 3D graphene not only improve conductivity but also provide double protection to alleviate the volume variation of FeS2 during cycling. Consequently, FeS2@C/G exhibits excellent cyclability (83.3% capacity retention after 300 cycles at 0.5A·g−1 with a capacity of 615.1 mA·h·g−1) and high rate capacity (475.1 mA·h·g−1 at 5A·g−1 after 2000 cycles). The pseudocapacitive process is evaluated and confirmed to significantly contribute to the high rate capacity of FeS2@C/G.
All Science Journal Classification (ASJC) codes
- Materials Science(all)