Free-standing NiCo2S4@VS2 nanoneedle array composite electrode for high performance asymmetric supercapacitor application
Free-standing NiCo2S4@VS2 nanoneedle array composite electrode for high performance asymmetric supercapacitor application
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DOI：
10.1016/j.jallcom.2018.08.325
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发表时间：
2019-01
影响因子：
6.2
通讯作者：
Zhiguo Zhang;Xiao Huang;Hongxia Wang;Siow Hwa Teo;T. Ma
中科院分区：
文献类型：
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作者：
Zhiguo Zhang;Xiao Huang;Hongxia Wang;Siow Hwa Teo;T. Ma
采用原位硫化辅助水热法制备了沿着NiCo 2S 4针状阵列排列的二维VS 2纳米片。利用场效应扫描电子显微镜（FESEM）、高分辨透射电子显微镜（HRTEM）和X射线衍射仪对样品的结构和物相进行了表征。通过循环伏安法、充放电曲线和电化学阻抗谱等测试手段对材料的电化学性能进行了表征。无粘结剂的NiCo2S4@VS2电极具有1023的高比容量。4 C g-1，具有显著的稳定性，由于协同效应，在0.45 A g-1的电流密度下，在2000次循环后，其容量保持96%。为便于实际应用，制备了以NiCo2S4@VS2为正极、活性炭（AC）为负极、聚丙烯为隔膜的非对称超级电容器（ASC）。组装的ASC在775 W kg− 1的功率密度下的最大能量密度为31.2 Wh kg− 1，在不同电流密度下具有良好的稳定性。因此，这种合理的设计为合成高性能超级电容器电极材料提供了新的策略。
Two-dimensional (2D) VS2nanosheets along the NiCo2S4needle arrays were prepared via an in situ sulfurization-assisted hydrothermal process. The unique nanostructure and phase were characterized by using field effect scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction. The electrochemical properties were recorded by cyclic voltammetry, charge/discharge curves, and electrochemical impedance spectroscopy. The binder-free NiCo2S4@VS2electrode has contributed to a high specific capacity of 1023. 4 C g−1with remarkable stability where 96% of its capacity retained after 2000 cycles at the current density of 0.45 A g−1due to the synergetic effects. Promoting for practical applications, an asymmetric supercapacitor (ASC) composed of NiCo2S4@VS2as the positive electrode and activated carbon (AC) as the negative electrode with polypropylene as the separator was fabricated. The assembled ASC contributed to a maximum energy density of 31.2 Wh kg−1at the power density of 775 W kg−1with good stabilities under different current densities. Thereby, this rational design provides a new strategy for synthesizing electrode materials for high-performance supercapacitors.