The relationship between the high-frequency performance of supercapacitors and the type of doped nitrogen in the carbon electrode
Nitrogen doping has been widely used to improve the performance of carbon electrodes in supercapacitors,particu-larly in terms of their high-frequency response.However,the charge storage and electrolyte ion response mechanisms of different ni-trogen dopants at high frequencies are still unclear.In this study,melamine foam carbons with different configurations of surface-doped N were formed by gradient carbonization,and the effects of the configurations on the high-frequency response behavior of the supercapacitors were analyzed.Using a combination of experiments and first-principle calculations,we found that pyrrolic N,charac-terized by a higher adsorption energy,increases the charge storage capacity of the electrode at high frequencies.On the other hand,graphitic N,with a lower adsorption energy,increases the speed of ion response.We propose the use of adsorption energy as a prac-tical descriptor for electrode/electrolyte design in high-frequency applications,offering a more universal approach for improving the performance of N-doped carbon materials in supercapacitors.
国家科技期刊平台
NSTL
万方数据
