Guo Xin, Li Menggang, Liu Yequn, Huang Yarong, Geng Shuo, Yang Weiwei, Yu Yongsheng
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China.
Analytical Instrumentation Center, State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China.
J Colloid Interface Sci. 2020 Mar 15;563:405-413. doi: 10.1016/j.jcis.2019.12.076. Epub 2019 Dec 17.
Rational construction of MnCoO-based core-shell nanomaterials with distinctive and desirable architectures possesses great potential in the advanced electrode material of high-performance supercapacitors. Here, a new class of hierarchical core-shell nanowire arrays (NWAs) with a shell of NiWO nanoparticles and a core of MnCoO nanowires is reported, which can significantly improve the electrochemical energy storage properties of supercapacitors. The unique core-shell structure endows the MnCoO@NiWO NWAs electrode with a high areal specific capacitance of 5.09 F cm at a current density of 1 mA cm and a superior cyclic retention of 96% after 5000 charge-discharge cycles, which are more preferable than those of MnCoO NWAs electrode. More importantly, an aqueous electrochemical energy storage device (core-shell MnCoO@NiWO NWAs as the positive electrode and active carbon as the negative electrode, MnCoO@NiWO//AC ASC) was assembled and shows a high energy density of 0.23 mWh cm at a power density of 2.66 mW cm, and 0.09 mWh cm at 16.00 mW cm, indicating hopeful potential for practical applications. This work highlights the significance of NiWO as a shell for hierarchical core-shell nanostructures, which can further improve the electron transport characteristic of the electrode material, thereby achieving performance breakthroughs in energy storage devices.
构建具有独特且理想结构的基于锰酸钴的核壳纳米材料，在高性能超级电容器的先进电极材料方面具有巨大潜力。在此，报道了一类新型的分级核壳纳米线阵列（NWAs），其外壳为钨酸镍纳米颗粒，核心为锰酸钴纳米线，这可显著改善超级电容器的电化学储能性能。独特的核壳结构赋予了锰酸钴@钨酸镍纳米线阵列电极在电流密度为1 mA/cm²时5.09 F/cm²的高面积比电容，以及在5000次充放电循环后96%的优异循环保持率，这比锰酸钴纳米线阵列电极更具优势。更重要的是，组装了一种水系电化学储能装置（以核壳锰酸钴@钨酸镍纳米线阵列作为正极，活性炭作为负极，锰酸钴@钨酸镍//活性炭不对称超级电容器），在功率密度为2.66 mW/cm²时显示出0.23 mWh/cm²的高能量密度，在16.00 mW/cm²时为0.09 mWh/cm²，表明其在实际应用中具有可观的潜力。这项工作突出了钨酸镍作为分级核壳纳米结构外壳的重要性，其可进一步改善电极材料的电子传输特性，从而在储能装置中实现性能突破。
