Heteroatom-doped nanostructured porous carbons have attracted intensive attention for electrical-double layer capacitors (EDLCs) because of their large surface area and surface functionalization. Here we use biowaste sepia ink as a sustainable source to synthesize nitrogen-doped highly porous carbon nanospheres by a simple molten salt-based activation strategy. The introduction of molten salt is not only beneficial for repairing the carbon conjugate network, but can also further improve the activation effect of porogen. The as-obtained carbon nanospheres (MA-NCS) displayed a large surface area of 1760 m2 g−1, optimized pore architecture, and high nitrogen content (8.6 wt %). With this design, the MA-NCS as EDLCs electrode exhibited a remarkable specific capacitance of 320 F g−1 at the current density of 0.5 A g−1 and high rate capability in 6 m KOH electrolyte. Furthermore, the assembled EDLCs demonstrated a high specific capacitance of 130 F g−1 at 0.5 A g−1 in an organic electrolyte (1 m TEABF4/AN), obtaining a maximum energy density of 28.2 Wh kg−1 at a power density of 625 W kg−1. This novel biowaste precursor-synthesis route presents great potential for facile large-scale production of high-performance porous carbons for green and long-term energy storage.
- molten salt-based activation
- porous carbon nanospheres
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Materials Chemistry