Shin Junhyeop, Park Jong-Kwon, Kim Geon Woo, Nam Inho, Park Soomin
School of Chemical Engineering and Materials Science, Department of Intelligent Energy and Industry, Department of Advanced Materials Engineering, Chung-Ang University, Seoul 06974, Korea.
School of Energy, Materials and Chemical Engineering, Korea University of Technology and Education, Cheonan 31253, Korea.
Micromachines (Basel). 2022 Jul 15;13(7):1113. doi: 10.3390/mi13071113.
The increasing use of rapidly fluctuating renewable energy sources, such as sunlight, has necessitated the use of supercapacitors, which are a type of energy storage system with high power. Chemically exfoliated graphene oxide (GO) is a representative starting material in the fabrication of supercapacitor electrodes based on reduced GO (rGO). However, the restacking of rGO sheets driven by π-π stacking interactions leads to a significant decrease in the electrochemically active surface area, leading to a loss of energy density. Here, to effectively inhibit restacking and construct a three-dimensional wrinkled structure of rGO (3DWG), we propose an agarose gel-templating method that uses agarose gel as a soft and removable template. The 3DWG, prepared via the sequential steps of gelation, freeze-drying, and calcination, exhibits a macroporous 3D structure and 5.5-fold higher specific capacitance than that of rGO restacked without the agarose template. Further, we demonstrate a "gel-stamping" method to fabricate thin-line patterned 3DWG, which involves the gelation of the GO-agarose gel within micrometer-sized channels of a customized polydimethylsiloxane (PDMS) mold. As an easy and low-cost manufacturing process, the proposed agarose gel templating method could provide a promising strategy for the 3D structuring of rGO.
随着太阳能等快速波动的可再生能源使用的增加，有必要使用超级电容器，它是一种高功率储能系统。化学剥离的氧化石墨烯（GO）是基于还原氧化石墨烯（rGO）制备超级电容器电极的代表性起始材料。然而，由π-π堆积相互作用驱动的rGO片层重新堆叠会导致电化学活性表面积显著减小，从而导致能量密度损失。在此，为了有效抑制重新堆叠并构建rGO的三维褶皱结构（3DWG），我们提出了一种琼脂糖凝胶模板法，该方法使用琼脂糖凝胶作为柔软且可去除的模板。通过凝胶化、冷冻干燥和煅烧的连续步骤制备的3DWG呈现出大孔三维结构，其比电容比没有琼脂糖模板重新堆叠的rGO高5.5倍。此外，我们展示了一种“凝胶压印”方法来制造细线图案化的3DWG，该方法涉及在定制的聚二甲基硅氧烷（PDMS）模具的微米级通道内使GO-琼脂糖凝胶凝胶化。作为一种简单且低成本的制造工艺，所提出的琼脂糖凝胶模板法可为rGO的三维结构化提供一种有前景的策略。
