An in-situ Blowing-etching strategy for preparation of Macro-meso-micro hierarchical porous carbon and its supercapacitive property

With the development of society, there exists a great need for symmetric supercapacitors that can be charged and discharged in long cycles, which puts forward higher requirements for symmetric supercapacitor materials. Porous carbon supercapacitors have attracted much attention because of their excellent performance, yet it is still difficult to build a structure with hierarchical pore carbon. Here, we report a new idea of constructing hierarchically porous carbon materials (HPC) by an in-situ blowing-assisted high-temperature etching method, and the pore structure can be tuned to a certain extent. It has a large number of meso-microporous structure with three-dimensional macro- interconnections, which is confirmed by electron microscope and nitrogen isothermal adsorption experiments. As an electrode material for supercapacitors, the optimized HPC exhibits an outstanding rate capability of 255.5F.g(-1) at a current density of 3 A.g(-1) and 201.6F.g(-1) at a current density of 10 A.g(-1) as well as an excellent cycle stability (capacity retention of 97.5% after 5000 cycles). The excellent performance originates from the favorable pore configuration that the macro-mesopores effectively accelerate ion transport and the micropores' interface store a large amount of charge. This work offering a new synthesis strategy and a new pore configuration prototype for the preparation of high-performance symmetric supercapacitor devices.