Synthesis of B-C-N Composite from Melamine-Formaldehyde Resins Containing Boron and Its Electric Double Layer Capacitor Performance

Abstract

Melamine-formaldehyde resin including boron (MFB resin) was prepared from melamine, formaldehyde and boric acid. B-C-N composite was prepared by pyrolysis of its MFB resin at 800-1000 ºC for 1 h in an inert atmosphere. Nitrogen contents in its B-C-N composite was kept high ratio of N/C, up to 0.24, in spite of heat treatment temperature. Boron contents depended on the ratio of formaldehyde added. Electric double layer capacitor (EDLC) performance of samples was evaluated in 40 % H₂SO₄ aqueous electrolyte by CV characteristic and galvanostatic charge/discharge measurement using three electrode cell. Electric double layer capacitor performance was as high as 500 F/g (1.1 F/m²). The specific surface area of B-C-N composite obtained is shown 300-600 m²/g. From the standpoint of specific capacitance per unit surface area, electric double layer capacitor performance increased with increasing N/C and it is shown the correlation between electric double layer capacitor performance and N/C.