Carbon-Coated Na3V2(PO4)3 Anchored on Freestanding Graphite Foam for High-Performance Sodium-Ion Cathodes

Na3V2(PO4)(3) (NVP) has been considered as a most promising cathode material for sodium-ion batteries (SIBs), but NVP usually exhibits poor cycling stability and rate performance due to the low intrinsic electrical conductivity. Herein, we prepared carbon-coated Na3V2(PO4)(3) anchored on freestanding graphite foam (denoted as NVP@C-GF) as a cathode for SIBs. The NVP@C-GF exhibits superior sodium-ion storage performance, including rate capability (56 mAh g(-1) at 200 degrees C) and long cycle life (54 mAh g(-1) at 100 degrees C after 20 000 cycles). The resulting NVP@C-GF inherits the advantages of 3D free-standing graphite that possesses high electrical conductivity and porous structure for the electrolyte to soak in. Furthermore, carbon coated NVP particles anchored on the surface of GF not only accommodate the volume change of NVP during charge/discharge but also reduce the diffusion distance of the Na+ ion.