Macro–microporous carbon for supercapacitors derived from rape seed shell

• Macro–microporous carbons were synthesized by directly using rape seed shell via impregation-activation route for use in supercapacitors.
• This approach permits the high specific surface area and a unique hierarchical porous structure which consists of interconnected macroporous skeleton and a significant microporosity.
• The resultant electrode materials provide important prospect for electrode materials in electric double layer capacitors, with remarkable values of capacitance of up to 225 F g−1 at a current density of 1 A g−1 in 2 M KOH electrolyte.

In this work, a novel macro–microporous architecture is successfully constructed in a honeycomb-like structure by directly using rape seed shell via impregation-activation route. This approach permits the high specific surface area (SSA) and a unique hierarchical porous structure which consists of interconnected macroporous skeleton and a significant microporosity. The unique honeycomb-like network combined with high specific surface area is favorable for charging the electric double-layer. The resulting carbon is highly suitable as electrodes of electric double layer capacitors, with remarkable values of capacitance of up to 225 F g−1 at a current density of 1 A g−1 in 2 M KOH electrolyte. Therefore, the as-prepared carbon can be a potential candidate for supercapacitors.