Zhang Yu, Zhang Yihe, Zhang Yuanxing, Si Haochen, Sun Li
Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing, 100083, People's Republic of China.
Nanomicro Lett. 2019 Apr 23;11(1):35. doi: 10.1007/s40820-019-0265-1.
Bimetallic Ni-Co sulfides are outstanding pseudocapacitive materials with high electrochemical activity and excellent energy storage performance as electrodes for high-performance supercapacitors. In this study, a novel urchin-like NiCoS@mesocarbon microbead (NCS@MCMB) composite with a core-shell structure was prepared by a facile two-step hydrothermal method. The highly conductive MCMBs offered abundant adsorption sites for the growth of NCS nanoneedles, which allowed each nanoneedle to fully unfold without aggregation, resulting in improved NCS utilization and efficient electron/ion transfer in the electrolyte. When applied as an electrode material for supercapacitors, the composite exhibited a maximum specific capacitance of 936 F g at 1 A g and a capacitance retention of 94% after 3000 cycles at 5 A g, because of the synergistic effect of MCMB and NCS. Moreover, we fabricated an asymmetric supercapacitor based on the NCS@MCMB composite, which exhibited enlarged voltage windows and could power a light-emitting diode device for several minutes, further demonstrating the exceptional electrochemical performance of the NCS@MCMB composite.
双金属镍钴硫化物是一类出色的赝电容材料，作为高性能超级电容器的电极，具有高电化学活性和优异的储能性能。在本研究中，通过简便的两步水热法制备了一种具有核壳结构的新型海胆状NiCoS@介孔碳微球（NCS@MCMB）复合材料。高导电性的MCMB为NCS纳米针的生长提供了丰富的吸附位点，使每根纳米针能够充分展开而不聚集，从而提高了NCS的利用率，并实现了电解质中高效的电子/离子转移。当用作超级电容器的电极材料时，由于MCMB和NCS的协同效应，该复合材料在1 A g时表现出936 F g的最大比电容，在5 A g下循环3000次后电容保持率为94%。此外，我们基于NCS@MCMB复合材料制备了一种不对称超级电容器，其具有扩大的电压窗口，可为发光二极管装置供电数分钟，进一步证明了NCS@MCMB复合材料优异的电化学性能。
