Sol-gel design strategy for embedded Na3V2(PO4)3 particles into carbon matrices for high-performance sodium-ion batteries

NASICON-type Na3V2(PO4)(3)(NVP) is one of the most promising cathode materials for sodium-ion batteries (SIBs). Here, we report a simple sol gel method to prepare NVP@C porous microspheres network for high performance SIBs, which can realize NVP nanoparticles successfully embedding into acetylene carbon (SP) and multiple walled carbon nanotubes (MCNTs) matrices. The electrochemical characterizations demonstrate that both NVP/SP and NVP/MCNTs show excellent cell performance with high rate ability and stable reversibility, especially for the NVP/MCNTs sample. In particular, as high as 112.8 mAh/g and 70 mAh/g of the discharge capacity for NVP/MCNTs system can be delivered at 0.2C and 10C, respectively. Furthermore, a good capacity retention of 90% can be maintained after 400 cycles at 1C rate. Moreover, the enhanced electrode performance is ascribed to the contribution from both of the porous microspheres morphology and functional carbon matrices, which can favor the migration of both electrons and ions. (C) 2015 Elsevier Ltd. All rights reserved.