Nitrogen and oxygen codoped porous carbon based on a synthetic polymer for high-performance solid-state supercapacitors

Most commercial supercapacitors are fabricated using porous carbon; however, their energy densities are relatively low. To further improve the energy storage performance of supercapacitors assembled using carbon materials, a novel synthetic polymer-derived carbon (SPMA-BQ-x-T) material was prepared by a facile and low-cost strategy. The SPMA-BQ-x-T materials exhibit coexistent structure of micropores and mesopores, homogeneous N, O codoping, and connected spherical morphology. In addition, although SPMA-BQ-x-T materials have low N-doping content (<2 %), they show large specific surface area of approximately 2000 m2 g-1, which maybe partly attribute to the abundance C-N single bonds existed in the precursor of SPMA-BQ. They are further used as the electrode materials in supercapacitors. The electrodes (SPMA-BQ-5-800) prepared under the optimal conditions show a high specific capacitance of 414.6 F g-1 at 0.5 A g-1 in a three-electrode system and 254 F g-1 at 0.5 A g-1 in solid-state supercapacitors (SSCs). The SSCs also display high energy density, long-term cycling stability, and good rate capability, suggesting their application potential in energy storage fields. This work achieves good electrochemical effect without pursuing high N-doping content by using a facile and low-cost preparation strategy, which has certain significance for the trade-off of specific surface area and N-doping content.