Yu Wei, Gao Mengqiu, Li Ben Q, Liang Jin, Ding Shujiang
Xi'an Key Laboratory of Sustainable Energy Materials Chemistry, Department of Applied Chemistry, School of Science, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China. Micro/Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
Nanotechnology. 2020 Sep 11;31(37):375301. doi: 10.1088/1361-6528/ab991d. Epub 2020 Jun 3.
Microsupercapacitors of air@NiO porous nanoshells are manufactured by a novel thermally-assisted 3D printing process. It entails the use of printing inks of the moderate solid content of CNT-PS@Ni-precursor-nanoparticle mixture, a real-time heating substrate to print 3D interdigital electrodes, and subsequent thermal annealing to convert PS@Ni-precursor particles into air@NiO porous nanoshells. The microstructure of 3D printed electrodes is characterized by air@NiO porous nanoshells being well dispersed in the CNT network. The CNT network provides a fast electronic migration path and meanwhile ensures the mechanical integrity of electrodes to prevent the fracture and/or collapsing of electrode structures during 3D printing manufacturing and charging/discharging cycles. The air@NiO porous nanoshells, manufactured in our labs, consist of randomly oriented nanosheets and offer superb charge storage via redox reactions. The metal layer is sputtered indiscriminately on the surface of interdigital electrodes and substrate before it is peeled off with electrolyte film and electrodes. The proposed tactic resolves problems connected with the tedious courses of traditional lithography and the delamination at the interface of active materials and collectors from mechanical stress. Experiments were conducted to study the performance of the microsupercapacitors (i.e. areal capacitances, energy and power densities) as a function of printing parameters, such as electrode heights, embedded amount of air@NiO porous nanoshells and the thickness of the metal layer on the electrochemical characteristics. The thickness of as-printed electrodes reaches up to 117 μm, which is vital in ensuring high energy density and is beyond the reach of any other technology. Moreover, the 3D printedmicrosupercapacitors of air@NiO porous nanoshells show excellent cycle stability and deliver an excellent areal capacitance of 56.7 mF cm, about a magnitude or two higher than that of C-based counterparts.
空气@NiO多孔纳米壳微超级电容器是通过一种新型热辅助3D打印工艺制造的。它需要使用具有适度固体含量的CNT-PS@Ni前驱体-纳米颗粒混合物的印刷油墨、用于打印3D叉指电极的实时加热基板，以及随后的热退火，将PS@Ni前驱体颗粒转化为空气@NiO多孔纳米壳。3D打印电极的微观结构的特征是空气@NiO多孔纳米壳在CNT网络中良好分散。CNT网络提供了快速的电子迁移路径，同时确保电极的机械完整性，以防止电极结构在3D打印制造和充电/放电循环过程中破裂和/或坍塌。我们实验室制造的空气@NiO多孔纳米壳由随机取向的纳米片组成，并通过氧化还原反应提供出色的电荷存储。在将电解质膜和电极剥离之前，金属层被无差别地溅射在叉指电极和基板的表面上。所提出的策略解决了与传统光刻的繁琐过程以及活性材料与集流体界面处因机械应力导致的分层相关的问题。进行了实验以研究微超级电容器的性能（即面积电容、能量和功率密度）作为打印参数的函数，例如电极高度、空气@NiO多孔纳米壳的嵌入量以及金属层厚度对电化学特性的影响。打印电极的厚度可达117μm，这对于确保高能量密度至关重要，并且是任何其他技术都无法达到的。此外，空气@NiO多孔纳米壳的3D打印微超级电容器表现出出色的循环稳定性，并提供56.7 mF/cm²的出色面积电容，比基于碳的同类产品高大约一到两个数量级。
