School of Materials Science and Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science and Technology, 710021, Xi'an, P.R. China.
Dalton Trans. 2019 Mar 19;48(12):3906-3913. doi: 10.1039/c9dt00041k.
The search for Earth-abundant and efficient electrode materials is significant for advanced supercapacitors. Here we introduce a facile strategy for one-step synthesis of Ni0.85Se nanowires via a composite alkali salt method. When used as an electrode material in supercapacitors, the as-prepared Ni0.85Se nanowires exhibit a high specific capacitance of 1354 F g-1 at a current density of 1 A g-1, and still retain 671 F g-1 at 30 A g-1. The superior electrochemical performance of the Ni0.85Se electrode can be attributed to the metallic conductivity of nickel selenides and fast electrical transport along the axial direction due to the nanowire morphology. For practical applications, an asymmetric supercapacitor was assembled by using Ni0.85Se and activated carbon, which delivered a high energy density of 40.7 W h kg-1 at a power density of 800 W kg-1 and 12.1 W h kg-1 at 16 kW kg-1. Moreover, the device retained 92.4% specific capacitance after 20 000 cycles at a high current density of 5 A g-1, showing its promising application prospects.
寻找丰富且高效的电极材料对于先进的超级电容器而言具有重要意义。在此，我们介绍了一种通过复合碱盐法一步合成 Ni0.85Se 纳米线的简便策略。将所制备的 Ni0.85Se 纳米线用作超级电容器的电极材料时，在 1 A g-1 的电流密度下具有 1354 F g-1 的高比电容，在 30 A g-1 的电流密度下仍保持 671 F g-1。Ni0.85Se 电极具有优异的电化学性能，这归因于镍硒化物的金属导电性和纳米线形态沿轴向的快速电子输运。为了实际应用，我们组装了一个由 Ni0.85Se 和活性炭构成的非对称超级电容器，在 800 W kg-1 的功率密度下可提供 40.7 W h kg-1 的高能量密度，在 16 kW kg-1 的功率密度下可提供 12.1 W h kg-1 的能量密度。此外，该器件在 5 A g-1 的高电流密度下循环 20000 次后仍保留 92.4%的比电容，显示出其广阔的应用前景。
