Improving the structural stability and reaction kinetic of Na3V2(PO4)3 through tungsten doping towards the ultralong cycle performance and excellent temperature tolerance of sodium ion batteries

Abstract

A series of carbon-coated tungsten doping NVP (Na(3-x)V(2-x)Wx(PO4)3@C, x = 0, 0.05, 0.1, 0.2, 0.3) was synthesized by sol–gel method. Characterization reveals that partial substitution of V by the larger W has beneficial influences on the structure and diffusion kinetics of NVP. Consequently, the optimized NVP-W0.1@C electrode releases a reversible initial capacity of 116 mA h g−1 at 1C, that is quite near to the theoretical value of pure NVP (117 mA h g−1). Furthermore, it delivers a high reversible capacity of 83.6 mA h g−1 at 50C with marvelous 94.3 % retention over 18,000 cycles. Desirable performances are demonstrated at −20 °C and 45 °C respectively, suggesting its viability in harsh environment. This work shed a light on scalable and feasible routine to regulate SIBs-based cathodes with promising performances.