The effects of anions on the structure and the electrochemical performance of carbon materials for supercapacitors

Abstract

A simple method by using Ni-based salts as the catalysts has been successfully developed to prepare porous carbons. The results show that Ni-based salts significantly affect the morphology, porous structure and graphitization degree of carbon materials. More importantly, it is found that the anions in the Ni-based salts also play important roles sor have synergistic effects for the formation of carbon materials. The obtained porous carbons can be used as electrode materials for supercapacitors and present excellent electrochemical behaviors. It is found that mesopores can accelerate the ion diffusion, ensuring full utilization of micropores and increasing gravimetric capacitance. Furthermore, a rational proportion between mesopores and micropores is also important for improving the electrochemical performance of porous carbons. In addition, the better electron conductivity arising from higher graphitization degree is also beneficial for the improvement of electrochemical behaviors.