Design and understanding of dendritic mixed-metal hydroxide nanosheets@N-doped carbon nanotube array electrode for high-performance asymmetric supercapacitors
Design and understanding of dendritic mixed-metal hydroxide nanosheets@N-doped carbon nanotube array electrode for high-performance asymmetric supercapacitors
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DOI：
10.1016/j.ensm.2018.06.026
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发表时间：
2019-01-01
影响因子：
20.4
通讯作者：
Liu, Meilin
中科院分区：
文献类型：
--
作者：
Zhang, Qiaobao;Liu, Zaichun;Liu, Meilin
设计和制造高能量密度、快速放电速率和长循环寿命的超级电容器具有重要意义；然而，sc的性能主要取决于材料发展的进步。在这里，我们报告了一种高性能电极材料的开发，该材料由层次化，多孔交错超薄Zn和Ni共取代碳化物氢氧化物（ZnNiCo-CHs）纳米片组成，该纳米片分支于n掺杂碳纳米管阵列（C@ZnNiCo-CHs）上，直接生长在镍泡沫集流器上。交错超薄zno - nico - chs纳米片的介孔特性和大的开放空间为氧化还原反应提供了更多的活性位点，促进了质量的快速传递；自立型氮掺杂碳纳米管阵列具有较大的比表面积，促进了电子的快速传递，增强了结构稳定性，具有出色的速率能力和长期稳定性。密度泛函理论计算表明，ZnNiCo-CHs纳米片具有较低的去质子化能，极大地促进了氧化还原反应的速率。此外，由C@ZnNiCo-CHs正极和N， s共掺杂rGOs负极组成的非对称SC在功率密度为966Wkg（-1）时具有70.9Wh kg（-1）的高能量密度，即使在20 a g（-1）下循环20,000次后仍保持91%的容量保持率。这一发现为合理设计过渡金属化合物基快速储能材料提供了一些重要见解，这可能适用于为其他能源相关器件创造高效、坚固的电极材料。
Design and fabrication of supercapacitors (SCs) with high energy density, fast discharge rate, and long cycle life is of great importance; however, the performances of SCs depend critically on advances in materials development. Here we report the development of a high-performance electrode material composed of hierarchical, porous interlaced ultrathin Zn and Ni co-substituted Co carbonate hydroxides (ZnNiCo-CHs) nanosheets branched on N-doped carbon nanotube arrays (C@ZnNiCo-CHs), which were grown directly on a nickel foam current collector. The mesoporous features and large open spaces of the interlaced ultrathin ZnNiCo-CHs nanosheets provide more active sites for redox reactions and facilitate fast mass transport; the self-standing N-doped carbon nanotube arrays offer large surface area, promote fast electron transport, and enhance structure stability, resulting in outstanding rate capability and long-term stability. Density functional theory calculations suggest that the ZnNiCo-CHs nanosheets have low deprotonation energy, greatly facilitating the rate of redox reactions. Further, an asymmetric SC constructed from a C@ZnNiCo-CHs positive electrode and an N-, S-codoped rGOs negative electrode demonstrates a high energy density of 70.9Wh kg(-1) at a power density of 966Wkg(-1) while maintaining a capacity retention of 91% even after 20,000 cycles at 20 A g(-1). The findings provide some important insight into rational design of transition metal compounds based materials for fast energy storage, which may be applicable to creating efficient and robust electrode materials for other energy-related devices.