Preparation and electrochemical performance of chemical‐activated carbon foam

Abstract

Three-dimensional porous carbon foam is fabricated by thermal pyrolysis of melamine foam and applied for energy storage electrode material. The increase of carbonization temperature is beneficial to improving graphitization degree and meanwhile lowing mechanical stability of carbon foam. KOH and Ni(NO3)2-activated carbonization is applied to further improve graphitization of carbon foam, leading to the improved conductivity. The ohmic resistance declines from 305 Ω cm–1 for bare carbon foam to 198 Ω cm–1 for KOH-activated one and 58 Ω cm–1 for Ni(NO3)2-activated one. The specific capacitance increases from 0.371 mF cm–2 for bare carbon foam to 0.905 mF cm–2 for KOH-activated one and 1.267 mF cm–2 for Ni(NO3)2-activated one at the current density of 0.1 mA cm–2. The activation thermal carbonization can improve the electroactivity of carbon foam. The fractured framework lowers mechanical stability of the chemical-activated carbon foams. Ni(NO3)2-activated carbon foam shows higher graphitization degree and electrical conductivity than KOH-activated one, accordingly contributing to higher electrochemical capacitance and rate capability. Ni(NO3)2-activation become more effective to enhance graphitization degree of carbon foam.