Three-dimensional NiCo2O4@NiWO4 core-shell nanowire arrays for high performance supercapacitors
Three-dimensional NiCo2O4@NiWO4 core-shell nanowire arrays for high performance supercapacitors
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DOI：
10.1039/c6ta08578d
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发表时间：
2017-01-21
影响因子：
11.9
通讯作者：
Zheng, Huajun
中科院分区：
文献类型：
--
作者：
Chen, Sanming;Yang, Guang;Zheng, Huajun
采用水热法和后热处理相结合的方法制备了以泡沫镍为载体的分级结构NiCo2O4@NiWO4核壳纳米线阵列。水热合成的NiCo 2 O 4纳米线阵列作为锚定NiWO 4纳米片的支架。当作为超级电容器的无粘合剂电极进行评估时，优化的NiCo2O4@NiWO4混合电极表现出显著的电化学性能，在1 A g（-1）的电流密度下具有1384 F g（-1）的高比电容和优异的上级循环稳定性（在5 A g（-1）的电流密度下在6000次循环中保持87.6%）。此外，基于优化的NiCo2O4@NiWO4电极和活性炭的非对称超级电容器（ASC）与6 M KOH作为电解质组装。所制造的ASC装置可以在760 W kg（-1）的功率密度下实现41.5 W h kg（-1）的最大高能量密度。这种优异的超级电容性能是由于NiCo 2 O 4纳米线和NiWO 4纳米片独特的核-壳结构以及协同效应所致。
Hierarchical NiCo2O4@ NiWO4 core-shell nanowire arrays supported on nickel foam have been synthesized via a facile hydrothermal route coupled with a post-thermal treatment. The hydrothermally synthesized NiCo2O4 nanowire arrays serve as the scaffold for anchoring the NiWO4 nanosheets. When evaluated as binder-free electrodes for supercapacitors, the optimized NiCo2O4@ NiWO4 hybrid electrode demonstrates remarkable electrochemical performance with a high specific capacitance of 1384 F g(-1) at a current density of 1 A g(-1) and superior cycling stability (87.6% retention over 6000 cycles at a current density of 5 A g(-1)). In addition, an asymmetric supercapacitor (ASC) based on the optimized NiCo2O4@ NiWO4 electrode and activated carbon is assembled with 6 M KOH as the electrolyte. The as-fabricated ASC device can achieve a maximum high energy density of 41.5 W h kg(-1) at a power density of 760 W kg(-1). The excellent supercapacitive performance could be ascribed to the unique core-shell architecture and the synergistic effect from the NiCo2O4 nanowires and the ultrathin NiWO4 nanosheets.