Dual pore-former method to prepare nitrogen-doped hierarchical porous carbons for supercapacitors

Nitrogen-doped hierarchical porous carbons are an ideal electrode material for achieving high-performance supercapacitors. However, the design and control of hierarchical porous structure generally requires complicated synthesis steps and expensive pore-former, which greatly limits its development. A simple dual pore-former method with one-step carbonization is proposed to prepare nitrogen-doped hierarchical porous carbons (CHC-ZnK). The dual pore-former of zinc acetate and potassium citrate can not only prepare pores of different sizes through a variety of mechanisms, but also have a great complementary effect on the control of the carbon material structure . CHC-ZnK with the hierarchical porosity and the large surface area delivers high specific capacitance of 408.9 F g −1 and excellent rate performance. The assembled symmetric supercapacitor exhibits high energy density and can ensure that the light-emitting diode run normally.