Meng Jinku, Wu Guan, Wu Xingjiang, Cheng Hengyang, Xu Zhi, Chen Su
State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials Nanjing Tech University Nanjing 210009 P. R. China.
State Key Laboratory of Chemical Engineering East China University of Science and Technology 130 Meilong Road Shanghai 200237 P. R. China.
Adv Sci (Weinh). 2019 Nov 25;7(1):1901931. doi: 10.1002/advs.201901931. eCollection 2020 Jan.
Methods enabling the controllable fabrication of orderly structural and active nanomaterials, along with high-speed ionic pathways for charge migration and storage are highly fundamental in fiber-shaped micro-supercapacitors (MSCs). However, due to fiber-electrodes with compact internal microstructure and less porosity, MSCs usually display a low energy density. Here, an innovative microfluidic strategy is proposed to design ordered porous and anisotropic core-shell fibers based on nickel oxide arrays/graphene nanomaterials. Owing to the homogeneous microchannels reaction, the graphene core maintains a uniformly anisotropic porous structure, and the nickel oxide shell keeps steadily vertically aligned nanosheets. The MSC presents an ultrahigh energy density (120.3 µWh cm) and large specific capacitance (605.9 mF cm). This higher performance originates from the microfluidic-architected core-shell fiber with abundant ionic channels (plentiful micro-/mesopores), large specific-surface-area (425.6 m g), higher electrical conductivity (176.6 S cm), and sufficient redox activity, facilitating ions with quicker diffusion and greater accumulation. Considering those outstanding properties, a wearable self-powered system, converting and storing solar energy into electric energy, is designed to light up displays. This microfluidic strategy offers an effective way to design new structural materials, which will advance the development of next-generation wearable/smart industries.
对于纤维状微型超级电容器（MSC）而言，能够可控地制造有序结构和活性纳米材料的方法以及用于电荷迁移和存储的高速离子通道是非常基础的。然而，由于纤维电极内部微观结构致密且孔隙率较低，MSC通常表现出较低的能量密度。在此，提出了一种创新的微流体策略，以基于氧化镍阵列/石墨烯纳米材料设计有序多孔且各向异性的核壳纤维。由于微通道反应均匀，石墨烯核保持均匀的各向异性多孔结构，氧化镍壳保持稳定垂直排列的纳米片。该MSC呈现出超高能量密度（120.3 μWh cm）和大比电容（605.9 mF cm）。这种更高的性能源于具有丰富离子通道（大量微孔/介孔）、大比表面积（425.6 m g）、更高电导率（176.6 S cm）和足够氧化还原活性的微流体构建的核壳纤维，有利于离子更快扩散和更多积累。考虑到这些优异性能，设计了一种将太阳能转换并存储为电能的可穿戴自供电系统来点亮显示器。这种微流体策略提供了一种设计新型结构材料的有效方法，这将推动下一代可穿戴/智能产业的发展。
