Preparation of hierarchical porous carbon material derived from starch for high-performance electrochemical capacitor

•Hierarchical porous carbon was fabricated from low-cost starch.•Na2CO3 templates play important roles in the forming of hierarchical porous carbon.•The porous carbon has excellent performance in electrochemical capacitors.

Hierarchical porous carbon was fabricated from low-cost starch by the Na2CO3 template method followed by KOH activation. Structural characterization indicates that the porous carbon with a high specific surface area (1034 m2/g) is made up of interconnected micro-, meso-, and macropores. Electrochemical measurements show that it exhibits a high specific capacitance of 234 F/g at 2 A/g, good rate capability with a retention of 91% at 20 F/g, and good cycling performance with 98% retention over 1000 cycles at 2 A/g in 6 M KOH electrolyte, which makes it a promising electrode for high-performance electrochemical energy storage system.