Fe-alginate biomass-derived FeS/3D interconnected carbon nanofiber aerogels as anodes for high performance sodium-ion batteries

The development of anode materials with a high capacity, excellent rate capability, and acceptable stability for sodium-ion batteries (SIBs) is still an urgent issue. Here, we fabricated FeS nanoparticle (NP)/three-dimensional (3D) carbon nanofiber aerogels (CNA) composites utilizing Fe-alginate aerogels as the renewable precursor. In the FeS/CNA sample, well-distributed FeS NPs were embedded on a 3D-CNA network with high electron conductivity and a large specific surface area. Impressively, the FeS/CNA sample was evaluated as an anode electrode material for SIBs, and exhibited an excellent specific capacity (473 mA h g −1 at 0.1 A g −1 ) and outstanding rate capacity (291 mA h g −1 at 5 A g −1 ). In addition, 97.4% of the capacity, 385 mA h g −1 , was retained over 400 cycles at 2 A g −1 , indicating the prominent cycling stability of the FeS/CNA sample. The results were ascribed to the unique structure of the FeS particles embedded on interconnected CNAs, which could boost sodium ion diffusion and facilitate electrolyte access.