Fabrication of N-doped and shape-controlled porous monolithic carbons from polyacrylonitrile for supercapacitors

N-doped porous monolithic carbons (PMC) have been developed from polyacrylonitrile (PAN) via a template-free thermally induced phase separation (TIPS) approach followed by an easy pyrolysis process. Three-dimensional (3D) PAN monolith (PM) was firstly fabricated as the starting material. The shape of the 3D PM was designed during the phase separation step, revealing that the product carbons had the potential advantages of desired porosity and controllable shape. Two typical activation methods were employed and compared to prepare PMC. KOH-activated PMC showed a larger surface area of 1600 m(2) g(-1) and higher nitrogen content of 5.6% in comparison to that being activated in a carbon dioxide atmosphere (CD-PMC). The electrochemical measurements revealed that PMC possessed a high capacitance of 270 F g(-1) at 0.2 A g(-1) and 195 F g(-1) even at 100 A g(-1), ultra-high rate capability with 72% capacitance retention from 0.2 to 100 A g(-1) and outstanding cycling stability with 100% capacitance retention at 20 A g(-1) after 5000 cycles. These results demonstrate that the present facile and efficient synthetic strategy for PMC from PAN can benefit the promotion of its application in energy storage devices and it is highly likely to be extended to other polymer sources.