Hybrid Electrodes Based on Zn-Ni-Co Ternary Oxide Nanowires and Nanosheets for Ultra-High-Rate Asymmetric Supercapacitors
Hybrid Electrodes Based on Zn-Ni-Co Ternary Oxide Nanowires and Nanosheets for Ultra-High-Rate Asymmetric Supercapacitors
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DOI：
10.1021/acsanm.0c01419
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发表时间：
2020-09-25
影响因子：
5.9
通讯作者：
Kim, Byoung-Suhk
中科院分区：
文献类型：
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作者：
Acharya, Jiwan;Ko, Tae Hoon;Kim, Byoung-Suhk
在这项研究中，水解剂辅助的三维（3D）花状分级锌镍钴氧化物（ZNCO）纳米结构材料，其中包括二维（2D）ZNCO纳米片锚定与一维（1D）ZNCO纳米线架构，作为超高速超级电容器应用的无粘合剂电极直接通过一个简单的水热法制备泡沫镍，然后煅烧。所制备的花状3D分级ZNCO纳米结构的形态显著地取决于所使用的水解试剂的组合方法（脲、六亚甲基四胺、六亚甲基四胺-脲），其分别表示为ZNCO-U、ZNCO-H和ZNCO-HU。其中，所制备的ZnCO-HU电极具有优异的电化学性能，在1A g（-1）时的比容量为259.8mAh g（-1），在50 A g（-1）的高电流密度下的比容量保持率为83.9%，并且具有超过5000次的长循环稳定性。使用ZNCO-HU作为阴极和N掺杂的石墨烯水凝胶（NGH）作为阳极材料的组装的非对称超级电容器（ASC）装置在1A g（-1）下提供76.5mAh g（-1）的显著比容量和在10A g（-1）下69.65%的良好倍率性能。夹心式ASC在761.5 W kg（-1）的功率密度下显示出55.4 Wh kg（-1）的优异的上级能量密度和高达5000次循环的89%的优异容量保持率。
In this study, hydrolysis agent-assisted three-dimensional (3D) flowerlike hierarchical zinc-nickel-cobalt oxide (ZNCO) nanostructured materials, which consist of two-dimensional (2D) ZNCO nanosheets anchored with one-dimensional (1D) ZNCO nanowire architectures, as binder-free electrodes for ultrahigh-rate supercapacitor applications are directly fabricated on Ni foam via a facile hydrothermal method followed by calcination. The morphologies of the as-fabricated flowerlike 3D hierarchical ZNCO nanostructures dramatically depend on the combination method (urea, hexamethylenetetramine, hexamethylenetetramine-urea) of the hydrolysis reagents used, which are denoted ZNCO-U, ZNCO-H, and ZNCO-HU, respectively. Among them, the as-prepared ZNCO-HU electrode shows outstanding electrochemical performance with a higher specific capacity of 259.8 mAh g(-1) at 1 A g(-1), ultrahigh capacitance retention of 83.9% at a higher current density of 50 A g(-1), and remarkable long cycle stability over 5000 cycles. The assembled asymmetric supercapacitor (ASC) device using ZNCO-HU as the cathode and N-doped graphene hydrogel (NGH) as the anode materials delivers a noticeable specific capacity of 76.5 mAh g(-1) at 1 A g(-1) and good rate capability of 69.65% at 10 A g(-1). The sandwiched ASC displays a superior energy density of 55.4 Wh kg(-1) at a power density of 761.5 W kg(-1) and excellent capacity retention of 89% up to 5000 cycles.