Convergence Research Division, Korea Carbon Industry Promotion Agency (KCARBON), Jeonju 54853, Korea.
Department of Chemistry, Kunsan National University, Kunsan 54150, Korea.
Int J Mol Sci. 2022 Aug 1;23(15):8537. doi: 10.3390/ijms23158537.
A kenaf-derived activated carbon (KAC) for a high-power density supercapacitor was developed in this study through phosphoric acid activation. The N/77K isothermal adsorption-desorption curve was used to estimate the textural properties of KAC based on BET and BJH and the pore size distribution based on NLDFT. The electrochemical properties of KAC were analyzed by using the coin-type cell applying 1 M SPBBF/PC electrolyte, and the specific surface area and total pore volume were 1490-1942 m/g and 1.18-3.18 cm/g, respectively. The pore characteristics of KAC varied according to the activation temperature, and most KAC showed a mesoporous structure. As the activation temperature increased, the mesopore volume increased up to 700 °C, then decreased. The mesoporous structure of KAC resulted in a substantial decrease in the Warburg impedance as the ion diffusion resistance decreased. Hence, the specific capacitance of KAC decreased from 82.9 F/g to 59.48 F/g as the charge-discharge rate increased from 1 mA/g to 10 mA/g, with the rate of reduction at approximately 30%. The rate of reduction of KAC's specific capacitance was 50% lower compared with commercial activated carbon; hence, KAC is a more suitable electrode-active material for high power density supercapacitors.
本研究通过磷酸活化法开发了一种用于高功率密度超级电容器的麻基活性炭（KAC）。N/77K 等温吸附-脱附曲线用于根据 BET 和 BJH 以及 NLDFT 基于孔径分布估计 KAC 的结构特性。通过使用 1 M SPBBF/PC 电解质的硬币型电池分析 KAC 的电化学性能，比表面积和总孔体积分别为 1490-1942 m/g 和 1.18-3.18 cm/g。KAC 的孔特征根据活化温度而变化，大多数 KAC 表现出介孔结构。随着活化温度的升高，介孔体积增加到 700°C，然后减少。KAC 的介孔结构导致离子扩散阻力降低，Warburg 阻抗大幅降低。因此，KAC 的比电容从 82.9 F/g 降低到 59.48 F/g，随着充放电速率从 1 mA/g 增加到 10 mA/g，降低率约为 30%。与商业活性炭相比，KAC 比电容的降低率降低了 50%；因此，KAC 是用于高功率密度超级电容器的更合适的电极活性材料。
