Abstract Lignocellulosic biomass was converted into hierarchical porous carbon by using a physical activation technique under a carbon dioxide environment. Both direct and indirect CO2 activation routes were utilized to investigate the effect of processing parameters and the kinetics of the activation. The porosity, surface chemistry, and morphology of the activated carbons were characterized in addition to their proximate and ultimate analyses. This was followed by the preparation of the activated carbon electrodes and the fabrication and electrochemical testing of these electrodes within a symmetrical supercapacitor cell. The results showed a dominant microporous structure along with the limited content of larger pores for the activated carbons prepared via both direct and indirect activation. Along with the preserved natural pore structure of the biomass, an engineered pore structure was achieved which is highly beneficial for the supercapacitors with respect to the transport and storage of ions. The morphological analysis also revealed their tortuous porous structure. The maximum specific capacitances of 80.9 and 92.7 F/g at the current density of 100 mA/g were achieved after direct and indirect activation routes, respectively. The surface functional groups were also found to play a significant role in the resultant electrochemical performance of the supercapacitors.

中文翻译：

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通过间接和直接 CO2 活化木质纤维素生物质制备的用于超级电容器电极的活性炭

摘要 在二氧化碳环境下，通过物理活化技术将木质纤维素生物质转化为分级多孔碳。直接和间接 CO2 活化途径都用于研究加工参数和活化动力学的影响。除了它们的近似和最终分析外，还表征了活性炭的孔隙率、表面化学和形态。随后是制备活性炭电极，并在对称超级电容器电池内制造和电化学测试这些电极。结果表明，通过直接和间接活化制备的活性炭具有主要的微孔结构和有限的较大孔含量。除了保留生物质的天然孔隙结构外，还实现了工程化的孔隙结构，这对超级电容器在离子的传输和存储方面非常有利。形态分析还揭示了它们曲折的多孔结构。在直接和间接激活途径后，在 100 mA/g 的电流密度下分别实现了 80.9 和 92.7 F/g 的最大比电容。还发现表面官能团在超级电容器的电化学性能中起着重要作用。在直接和间接活化途径后，在 100 mA/g 的电流密度下分别达到 9 和 92.7 F/g。还发现表面官能团在超级电容器的电化学性能中起着重要作用。在直接和间接活化途径后，在 100 mA/g 的电流密度下分别达到 9 和 92.7 F/g。还发现表面官能团在超级电容器的电化学性能中起着重要作用。