High energy-power characteristics of microstructurally engineered sodium vanadium phosphate in full cell level

The demand for hybrid devices which can deliver high power with large storage capabilities are increasing day-by-day. Sodium based hybrid devices are an appropriate choice to meet the current necessities by considering the abundance, cost and performance. Sodium vanadium phosphate nanocomposite (NC-NVP) has been engineered by making the particles embedded within nitrogen doped mesoporous carbon matrix. Using NC-NVP, a hybrid cell has been devised with activated carbon in an asymmetric cell fashion and compared it with symmetric cell. Asymmetric and symmetric cells have demonstrated cell level energy densities of 77 & 65 and 59 & 46 Wh kg−1 at 0.1 and 1 A g−1 respectively, which are much higher than many reported values. At 2 A g−1, both configurations delivered high power (3722 and 3750 W kg−1) within 1.4 and 1.5 min at retentions of 63 and 51 % after 14,000 cycles respectively. Excellent electrochemical performance suggests that dual mechanism of intercalation in NC-NVP and surface/sub-surface charge storage in nitrogen-doped mesoporous carbon are playing major role. The obtained results are superior to different hybrid devices reported earlier which paves a way for demonstrating sodium-ion device for practical applications.