Electrochimica Acta, Vol.155, 23-28, 2015
Self-combustion synthesis of Na3V2(PO4)(3) nanoparticles coated with carbon shell as cathode materials for sodium-ion batteries
The real applications of Na3V2(PO4)(3) cathode material for sodium batteries have been hindered by low-cost and facile synthesis method. Herein, we report a facile self-combustion method to synthesize Na3V2(PO4)(3) nanoparticles coated with carbon shell (NVP/C). Using as the cathode, the NVP/C is capable of delivering the initial discharge and charge capacities of 100.72 and 111.3 mAh g(-1) at the current of 0.1 C in a voltage of 2.5-3.8 V, and the capacity retention of the sample is approximately 95% of its initial specific capacity after 50th cycles. The first-principles simulation results show that the Na ions migration route prefers between two adjacent tetrahedral sites with the vacancy-hopping mechanism in a curved way, with the lowest activation energy of 0.292 eV. The diffusion coefficients D-Na(+) at room temperature was also calculated as higher as 2.38 x 10(-9)cm(2)s(-1). The results suggest great potential of self-combustion synthesized NVP/C as cathode materials for Na-ion batteries. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords:Na3V2(PO4)(3);cathode materials;self-combustion synthesis;sodium ions diffusion;first-principles simulation