Synergistic relationship between the three-dimensional nanostructure and electrochemical performance in biocarbon supercapacitor electrode materials
Synergistic relationship between the three-dimensional nanostructure and electrochemical performance in biocarbon supercapacitor electrode materials
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DOI：
10.1039/c7se00519a
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发表时间：
2018-04-01
影响因子：
5.6
通讯作者：
Brett, Daniel J. L.
中科院分区：
文献类型：
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作者：
Abouelamaiem, Dina Ibrahim;He, Guanjie;Brett, Daniel J. L.
本文提出的一项新研究将多维形态与活性生物碳材料的电化学性能相关联，用于多个长度尺度上的超级电容器装置。超级电容器电极材料的氢氧化钾（KOH）/纤维素比率的优化与形态特征和相应的电化学性能有关，如在孔隙率、比表面积、比电容和电化学阻抗方面所描述的。KOH/纤维素比例为0.5：1和1：1的样品表现出最好的性能，其特征在于多级多孔网络结构，高比表面积和低电池电阻。与其他制备的样品和商业活性炭Ketjen Black（KB）、Norit活性炭（NAC）和珠状活性炭（BAC）相比，前两种样品在三电极系统和纽扣电池中显示出更好的结果，在1 A g（-1）的电流密度下，比重量电容高达187 F g（-1）。高性能归因于构成微孔、中孔和大孔的组合的样品的形态，从而得到高比表面积、高孔隙率、低电池电阻和高比电容。这进一步证实了在作者的模型KOH/纤维素系统中观察到的结构-性能关系，强调了该工作可以扩展到其他类似系统。很明显，为了优化电化学性能，必须完整地理解材料的三维纳米结构。
A novel study presented herein correlates the multidimensional morphology with the electrochemical performance of activated bio-carbon materials, for supercapacitor devices over multiple length scales. The optimization of the potassium hydroxide (KOH)/cellulose ratio for supercapacitor electrode materials is related to morphological characteristics and corresponding electrochemical performance, as described in terms of porosity, specific surface area, specific capacitance and electrochemical impedance. KOH/cellulose samples with ratios 0.5 : 1 and 1 : 1 exhibited the best performance, characterized by a hierarchal porous network structure, high surface area and low cell resistance. Compared with the rest of the manufactured samples and commercial activated carbons, Ketjen Black (KB), Norit activated carbon (NAC) and bead-shaped activated carbon (BAC), the former two samples showed better results in three-electrode systems and coin cells, with specific gravimetric capacitances as high as 187 F g(-1) at a current density of 1 A g(-1). The high performance is attributed to the morphology of the samples that constituted a combination of micro-, meso-and macroporosity which consequently gave high specific surface area, high porosity, low cell resistance and high specific capacitance. This further corroborates the structure-performance relationship observed in the author's model KOH/cellulose system, highlighting that the work can be extended to other similar systems. It is clear that the three-dimensional nanostructure of a material must be understood in its entirety in order to optimize the electrochemical performance.