School of Energy and Power Engineering, Shandong University, 250061, Jinan, P.R. China.
Sci Rep. 2019 Nov 21;9(1):17270. doi: 10.1038/s41598-019-53869-w.
It is generally acknowledged that the activation method and component of the precursor are of great importance for making porous carbon. In this study, four plant materials belong to one genus were selected as optimized plant material to produce hierarchical porous carbon for supercapacitors, the influence of initial structure was discussed. All the produced porous carbons have large specific surface area (higher than 2342 m g), high microporosity (more than 57%), and high pore volume (larger than 1.32 cm g). All the samples show characteristic of electrical double layer capacitance, and the onion-based porous carbon obtain highest specific capacitance of 568 F g at the current density of 0.1 A g. With the current density rising from 1 A g to 50 A g, the specific capacitance only decreases for 20%. After 5000 cycles, all the samples show relatively high capacitance retention (up to 97%). Two-step acid pickling has washed most impurities and directly lead to small equivalent series resistance (lower than 0.2 Ω). The samples show high power density and energy density (71 W h kg@180 W kg, 210 kW kg@33 W h kg). This study open an avenue to create high-performance hierarchical porous carbon based on plant architecture.
人们普遍认为，前驱体的活化方法和组成对于制备多孔碳非常重要。在这项研究中，选择了四个属于同一属的植物材料作为优化的植物材料，用于制备用于超级电容器的分级多孔碳，讨论了初始结构的影响。所有制备的多孔碳都具有大的比表面积（高于 2342 m g）、高的微孔率（超过 57%）和高的孔体积（大于 1.32 cm g）。所有样品均表现出双电层电容的特征，洋葱状多孔碳在 0.1 A g 的电流密度下获得了 568 F g 的最高比电容。随着电流密度从 1 A g 增加到 50 A g，比电容仅下降了 20%。经过 5000 次循环后，所有样品均表现出较高的电容保持率（高达 97%）。两步酸浸洗去除了大部分杂质，直接导致了较小的等效串联电阻（低于 0.2 Ω）。这些样品表现出高的功率密度和能量密度（71 Wh kg@180 W kg，210 kW kg@33 Wh kg）。本研究为基于植物结构制备高性能分级多孔碳开辟了一条途径。
