Hierarchical NiCo2O4@ NiCoAl-layered double hydroxide core/shell nanoforest arrays as advanced electrodes for high-performance asymmetric supercapacitors
Hierarchical NiCo2O4@ NiCoAl-layered double hydroxide core/shell nanoforest arrays as advanced electrodes for high-performance asymmetric supercapacitors
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DOI：
10.1016/j.jallcom.2017.06.256
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发表时间：
2017-11-15
影响因子：
6.2
通讯作者：
Wang, Jun
中科院分区：
文献类型：
--
作者：
He, Xinyi;Liu, Qi;Wang, Jun
提出了一种水热合成和分步原位结构制造工艺的组合，用于在没有粘合剂和导电剂的情况下在泡沫镍上生长分级核/壳结构的NiCo 2 O 4 @ NiCoAl-LDH。对于超级电容器电极，所获得的NiCo 2 O 4 @ NiCoAl-LDH纳米森林在1 A g（-1）的电流密度下显示出1814.24 F g（-1）的增强的比电容，并且在10 A g（-1）下在2000次循环后具有93%的循环性能。此外，基于NiCo 2 O 4 @ NiCoAl-LDH纳米森林电极和活性炭电极的非对称超级电容器实现了优异的电化学性能，在800 W kg（-1）的功率密度下的能量密度为74.64 Wh kg（-1），并且具有良好的循环稳定性（在2000次循环后保持86%）。电化学性能的改善归因于分级核/壳结构和活性物质的协同效应，增强了界面电荷传输，缩短了离子的扩散路径。这些结果表明，分级核/壳NiCo 2 O 4 @ NiCoAl-LDH纳米森林阵列是有希望的超级电容器应用。(C)2017爱思唯尔B. V.保留所有权利。
A combination of hydrothermal synthesis and a step-by-step in situ structure fabrication process for growing a hierarchical core/shell structure of NiCo2O4@ NiCoAl-LDH onto nickel foam without binders and conductive agents is presented. For supercapacitor electrodes, the as-obtained NiCo2O4@ NiCoAl-LDH nanoforest displays an enhanced specific capacitance of 1814.24 F g(-1) at a current density of 1 A g(-1) and a cycling performance with a retention of 93% after 2000 cycles at 10 A g(-1). Moreover, an asymmetric supercapacitor based on NiCo2O4@ NiCoAl-LDH nanoforest electrode and activated carbon electrode achieves an excellent electrochemical property with the energy density of 74.64 Wh kg(-1) at the power density of 800 W kg(-1) and good cycling stability (retaining 86% after 2000 cycles). The improved electrochemical performance is attributed to the hierarchical core/shell structure and synergistic effect of active materials, which enhance the interfacial charge transmission and shorten the diffusion path of ions. These results demonstrate that the hierarchical core/shell NiCo2O4@ NiCoAl-LDH nanoforest arrays are promising for supercapacitor applications. (C) 2017 Elsevier B.V. All rights reserved.