Liquid template synergizing combustion activation to construct vesicular porous carbon anode for sodium ion batteries

In this study, B, N and O tri-doped porous carbon material (EBNK) is successfully prepared by liquid template synergistic combustion activation. Benefiting from this method, the generated EBNK exhibits a unique vesicle-like spherical shell structure, which significantly accelerates the transport of sodium ions, and therefore the initial coulombic efficiency of its half-cells in ether-based electrolyte is as high as 95.6 %. Moreover, the synergistic effect of the three dopant atoms increases the number of defects and the spacing of the carbon layers, resulting in the EBNK anode exhibiting rare and excellent properties. The specific capacity is 487.5 mAh/g at 0.05 A/g, and 125 mAh/g at 50 A/g; the capacity is maintained at 138.9 mAh/g after 5500 cycles at 20 A/g. The NVP//EBNK full cell has an energy density of 192.2 Wh kg⁻¹ at a power density of 159.7 W kg⁻¹. This study will undoubtedly expand the methods for preparing sodium-ion batteries with excellent performance, provide new perspectives on the energy storage mechanism of multi-doped porous carbon, and promote the development of the energy storage field.