Synthesis of three-dimensional hierarchical porous carbon for high-performance supercapacitors

Three-dimensional hierarchical porous carbons were synthesized by direct carbonization of glucose and zinc nitrate mixtures. The effects of carbonization temperature on the formation of the microscopic pore structure were studied. When tested in 6 M KOH by three-electrode system, the carbon sample carbonized at 750 °C shows the best electrochemical performance compared to the other samples. High specific capacitance (276 F g−1) is obtained at 0.3 A g−1, and the capacitance still maintains 205 F g−1 when tested at 10 A g−1. Moreover, the sample also possesses good cycling stability with only a loss of 3.7% after 10,000 cycles at 5 A g−1. The facile preparation method and hierarchical porous structure render this carbon material a promising candidate for high-performance supercapacitors application.