Templated mesoporous carbons and their performance for electric double layer capacitors

Templated mesoporous carbons with high surface area were successfully prepared by the carbonization of a mixture of thermoplastic precursor pitch with MgO precursors (magnesium acetate and citrate) at 950℃ in a N₂ atmosphere. The BET surface area of the carbons obtained reached a very high value without any activation process. The carbons were rich in mesopores. The electrochemical performance of mesoporous carbons prepared as electrode materials for electric double layer capacitors were also investigated. Measurement of capacitance was carried out in a mass fraction 30% KOH electrolyte. Results showed that the mesoporous carbons had a high specific capacitance and perfect rate performance. In particular, the sample prepared with a mass ratio of MgO to pitch of 4 for the magnesium citrate template showed a fairly high capacitance, about 284F · g^-1 at a current density of 20mA · g^-1 and 236F · g^-1 at 1000mA · g^-1. The impedance of all the capacitors was smaller than 3. 5Ω.