High performance nitrogen-doped carbon for supercapacitor obtained by carbonizing eco-friendly and cheap polyaspartic acid

•Polyaspartic acid was used to prepare nitrogen-doped porous carbon.•The morphologies and structures of carbon deeply depend on carbonization temperature.•Carbon exhibits high specific capacitance and excellent cycling stability.•The approach may be used in all amino acids to prepare nitrogen-doped carbon.

Nitrogen-doped porous carbon is prepared by carbonizing polyaspartic acid under inertia atmosphere without template and activation. The powder X-ray diffraction, element analysis, scanning electron microscopy, and N2 adsorption–desorption tests show that the morphologies and structures of the nitrogen-doped carbon samples deeply depend on carbonization temperature. Electrochemical measurements show that the specific capacitance of the PASP700 sample obtained at 700 °C is 166.1 F g−1 at a current density of 1 A g−1, and after 5000 charge/discharge cycles it still remains 97% which exhibits an excellent cycling stability.

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