Design and preparation of hierarchical porous carbon-based materials with bionic "ant nest" structure for high performance asymmetric supercapacitors

Rational design of electrodes to broaden the working potential window is an attractive approach to improve the energy density of asymmetric supercapacitors. Herein, a simple non-solvent-induced phase separation method was used to construct a bionic "ant nest" three-dimensional hierarchical porous carbon (HPC) without any template, realizing a three-dimensional interlaced interconnection network structure similar to that of a natural ant nest, which adsorbs more ions through a larger accessible area and facilitates the bi-continuous transport of ions and electrons. Further, the aqueous asymmetric supercapacitor assembled with MnO2-modified HPC (HPC/ MnO2) as the positive electrode and nitrogen-doped HPC (NHPC) as the negative electrode has an energy density as high as 21 Wh kg-1 at a power density of 410 W kg-1, and as high as 17 Wh kg-1 even at a power density of 13 kW kg-1. The device exhibits an excellent electrochemical performance over a potential window of 0-1.6 V.