Green Energy Technology Research Center and Department of Materials Engineering, Kun Shan University, Tainan 710, Taiwan.
Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan.
Molecules. 2020 Sep 4;25(18):4050. doi: 10.3390/molecules25184050.
A series of heteroatom-containing porous carbons with high surface area and hierarchical porosity were successfully prepared by hydrothermal, chemical activation, and carbonization processes from soybean residues. The initial concentration of soybean residues has a significant impact on the textural and surface functional properties of the obtained biomass-derived porous carbons (BDPCs). SRAC5 sample with a BET surface area of 1945 m g and a wide micro/mesopore size distribution, nitrogen content of 3.8 at %, and oxygen content of 15.8 at % presents the best electrochemical performance, reaching 489 F g at 1 A g in 6 M LiNO aqueous solution. A solid-state symmetric supercapacitor (SSC) device delivers a specific capacitance of 123 F g at 1 A g and a high energy density of 68.2 Wh kg at a power density of 1 kW kg with a wide voltage window of 2.0 V and maintains good cycling stability of 89.9% capacitance retention at 2A g (over 5000 cycles). The outstanding electrochemical performances are ascribed to the synergistic effects of the high specific surface area, appropriate pore distribution, favorable heteroatom functional groups, and suitable electrolyte, which facilitates electrical double-layer and pseudocapacitive mechanisms for power and energy storage, respectively.
一系列具有高比表面积和分级孔结构的杂原子多孔碳，是通过水热、化学活化和碳化过程，由大豆残渣制备而成。大豆残渣的初始浓度对所得到的生物质衍生多孔碳（BDPCs）的结构和表面官能团特性有显著影响。具有比表面积 1945 m²/g、宽微孔/介孔分布、氮含量 3.8 at%和氧含量 15.8 at%的 SRAC5 样品，在 6 M LiNO 水溶液中，表现出最佳的电化学性能，在 1 A/g 时达到 489 F/g。固态对称超级电容器（SSC）器件在 1 A/g 时具有 123 F/g 的比电容和在 1 kW/kg 时 68.2 Wh/kg 的高能量密度，具有 2.0 V 的宽电压窗口，并且在 2 A/g（超过 5000 次循环）时保持良好的循环稳定性，电容保持率为 89.9%。优异的电化学性能归因于高比表面积、适当的孔分布、有利的杂原子官能团和合适的电解质的协同作用，这有利于电力和能量存储的双电层和赝电容机制。
