The effects of melamine on the formation of carbon xerogel derived from resorcinol and formaldehyde and its performance for supercapacitor

Carbon aerogel/xerogel can be easily tuned to have hierarchical pores ranging from micropores to macropores. Nitrogen doping is considered to enhance the wettability and conductivity of the carbon electrode, hence improve the electrochemical performance. To prepare N-doped carbon xerogel and study the effects on the structure and the electrochemical performance of resorcinol and formaldehyde derived carbon xerogel, a series of Resorcinol-Melamine-Formaldehyde derived N-doped carbon xerogel were prepared by a facile sol-gel process and ambient drying method. With the increasing amount of melamine, the inside channels become larger, which contributes to faster ion transport and smaller charge transfer resistance (R_ct). The Nitrogen content in carbon xerogel is also increased, enhancing the capacitance of carbon electrode by pseudocapacity effect, while damaging the rate performance by introducing more defects and larger degree of disorder. As a result, the best electrochemical performance is achieved in the RM-6-4 sample (resorcinol:melamine = 6:4), showing the largest capacitance of 139 F g^-1.