Revealing the Correlation of High-frequency Performance of Supercapacitors with Doped Nitrogen Species

However, the charge storage and ion response mechanisms of different nitrogen species at high frequencies is still unclear. In this study, we employ carbonized melamine foam with open surface structure as a simplified model material, enabling a comprehensive analysis of their impact on the ionic response behavior of high-frequency supercapacitors.

Through a combination of experiments and first-principles calculations, we uncover that pyrrolic nitrogen, characterized by a higher adsorption energy, enhances the charge storage capacity of the electrode at high frequencies. On the other hand, graphitic nitrogen, with a lower adsorption energy, promotes rapid ion response. Furthermore, we propose the use of adsorption energy as a practical descriptor for electrode/electrolyte design in high-frequency applications, offering a more universal approach for optimizing the performance of N-doped carbon materials.