Porous starch was used as a precursor for hierarchical porous carbon microspheres. The preparation consisted
of stabilisation, carbonisation and KOH activation, and the resultant hierarchical porous carbon
microspheres had a large BET surface area of 3251 m2 g1. Due to the large surface area and the hierarchical
pore structure, electrodes made of the hierarchical porous carbon microsphere materials had high
specific capacitances of 304 F g1 at a current density of 0.05 A g1 and 197 F g1 at a current density of
180 A g1 when used in a symmetric capacitor with 6 M KOH as the electrolyte. After 10,000 cycles, the
capacitor still exhibited a stable performance with a capacitance retention of 98%. These results indicate
that porous starch is an excellent precursor to prepare high performance electrode materials for EDLCs.