open access

https://hdl.handle.net/2115/42519

MgO-templated nitrogen-containing carbons derived from different organic compounds for capacitor electrodes

英語

Pseudo-capacitance

2010-01-15

Elsevier B.V.

Journal of Power Sources

195(2)

667-673

Carbons containing nitrogen (C-N composites) were derived from three commercial organic compounds, poly(vinylpyrrolidone) (PVP), polyacrylamide (PAA), and trimethylolmelamine (TMM) using the MgO template method. The C-N composites formed in nitrogen at 700-1000℃ had nitrogen content, W_[N], of 3-23 mass% and the specific surface area by N2 adsorption, S_[BET], of 60-2000 m2 g^[-1] without activation. Generally high nitrogen content of the starting compound led to larger W_[N], but W_[N] was not proportional to the N/C mole ratio in the compounds. The value of S_[BET] strongly depended on the compound: S_[BET] (PVP) > S_[BET] (PAA) >> S_[BET] (TMM). There was a tendency for W_[N] to decrease with increasing S_[BET]. The capacitance measured in 1 mol dm^[-3] H2SO4 by cyclic voltammetry, C_[M] in F g^[-1], suggested that both W_[N] and S_[BET] are influential in gaining large C_[M]. For the composites with W_[N] > 5 mass%, the capacitance normalized by S_[BET], C_[A] = C_[M]/S_[BET], was 0.17-0.65 F m^[-2], which was larger than the electric double layer capacitance (0.05-0.15 F m^[-2]), indicating that the pseudo-capacitance contributes significantly to C_[M]. The value of C_[A] increased with increasing W_[N], but a correlation between C_[A] and particular nitrogen species on the surface measured by XPS was obscure. It was suggested that the large C_[A] is not simply explained by redox reactions of the surface functional groups. The composite derived from PAA at 900℃ showed 234 F g^[-1] at 2 mV s^[-1] and 181 F g^[-1] at 100 mV s^[-1] with acceptable yield of the composite.

学術雑誌論文

Accepted Manuscript

0378-7753