Hydrogel self-templated synthesis of Na3V2(PO4)3@C@CNT porous network as ultrastable cathode for sodium-ion batteries

Abstract A hydrogel self-templated method was developed to produce Na 3 V 2 (PO 4 ) 3 @C@CNT 2D porous network (denoted as NVP@C@CNT) comprising 0D carbon coated Na 3 V 2 (PO 4 ) 3 nanoparticles and 1D carbon nanotubes. Such fascinating architecture offers high electronic and ionic conductivity, structure stability, as well as long-term cycling when used as a cathode for sodium-ion batteries (SIBs). The cathode displays an ultralong cyclability (94% capacity retention after 4500 cycles at 5C) and high rate capability. Such performance derives from the synergistic effect of porous network structure and carbon coating, which accelerates ion diffusion and improves structural integrity. Equally important, the proposed method provides a new avenue for the preparation of 2D porous materials for advanced energy storage applications.