Hong Zhong-Yun, Chen Lung-Chuan, Li Yu-Chu M, Hsu Hao-Lin, Huang Chao-Ming
Department of Materials Engineering, Kun Shan University, Tainan 710, Taiwan.
Department of Mechanical Engineering, Southern Taiwan University of Science and Technology, Tainan 710, Taiwan.
Molecules. 2022 Oct 13;27(20):6867. doi: 10.3390/molecules27206867.
In this work, NiCoS-graphene hybrids (NCS@G) with high electrochemical performance were prepared using a hydrothermal method. The response surface methodology (RSM), along with a central composite design (CCD), was used to investigate the effect of independent variables (G/NCS, hydrothermal time, and S/Ni) on the specific capacitances of the NCS@G/Ni composite electrodes. RSM analysis revealed that the developed quadratic model with regression coefficient values of more than 0.95 could be well adapted to represent experimental results. Optimized preparation conditions for NCS@G were G/NCS = 6.0%, hydrothermal time = 10.0, and S/Ni = 6.0 of NCS@G (111) sample. The maximum specific capacitance of NCS@G (111)/Ni fabricated at the optimal condition is about 216% higher than the best result obtained using the conventional experimental method. The enhanced capacitive performance of the NCS@G (111) sample can be attributed to the synergistic effect between NCS nanoparticles and graphene, which has the meso/macropores conductive network and low diffusion resistance. Notably, the NCS@G (111) could not only provide numerous reaction sites but also prevent the restacking of graphene layers. Furthermore, a supercapattery cell was fabricated with an (G + AC)/Ni anode, a NCS@G (111)/Ni cathode, and a carboxymethyl cellulose-potassium hydroxide (CMC-KOH) gel electrolyte. The NCS@G (111)//(G + AC) demonstrates an outstanding energy density of 80 Wh kg at a power density of 4 kW kg, and a good cycling performance of 75% after 5000 cycles at 2 A g. Applying the synthesis strategy of RSM endows remarkable capacitive performance of the hybrid materials, providing an economical pathway to design promising composite electrode material and fabricate high-performance energy storage devices.
在本工作中，采用水热法制备了具有高电化学性能的NiCoS-石墨烯杂化物（NCS@G）。响应面法（RSM）结合中心复合设计（CCD），用于研究自变量（G/NCS、水热时间和S/Ni）对NCS@G/Ni复合电极比电容的影响。RSM分析表明，所建立的回归系数值大于0.95的二次模型能够很好地拟合实验结果。NCS@G的优化制备条件为：G/NCS = 6.0%、水热时间 = 10.0以及NCS@G（111）样品的S/Ni = 6.0。在最佳条件下制备的NCS@G（111）/Ni的最大比电容比使用传统实验方法获得的最佳结果高出约216%。NCS@G（111）样品电容性能的增强可归因于NCS纳米颗粒与石墨烯之间的协同效应，其具有介观/大孔导电网络且扩散电阻低。值得注意的是，NCS@G（111）不仅可以提供大量反应位点，还能防止石墨烯层的重新堆叠。此外，用（G + AC）/Ni阳极、NCS@G（111）/Ni阴极和羧甲基纤维素-氢氧化钾（CMC-KOH）凝胶电解质制备了一个超级电容器电池。NCS@G（111）//（G + AC）在4 kW kg的功率密度下表现出80 Wh kg的出色能量密度，在2 A g下5000次循环后具有75%的良好循环性能。应用RSM的合成策略赋予了杂化材料卓越的电容性能，为设计有前景的复合电极材料和制造高性能储能装置提供了一条经济的途径。
