Hierarchical Structure Formation and Effect Mechanism of Ni/Mn Layered Double Hydroxides Microspheres with Large-Scale Production for Flexible Asymmetric Supercapacitors
Hierarchical Structure Formation and Effect Mechanism of Ni/Mn Layered Double Hydroxides Microspheres with Large-Scale Production for Flexible Asymmetric Supercapacitors
复制标题
柔性非对称超级电容器规模化生产的Ni/Mn层状双氢氧化物微球的分级结构形成及作用机制
DOI：
10.1021/acsaem.8b00321
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发表时间：
2018-05
影响因子：
6.4
通讯作者：
Ting Zhang
中科院分区：
文献类型：
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作者：
Tie Li;Jian Wang;Yan Xu;Yudong Cao;Hongzhen Lin;Ting Zhang
采用化学共沉淀法（55 °C，常压）制备了具有三维花状分级结构的Ni/Mn层状双金属氢氧化物（LDHs）微球。在每个集成微球中，花瓣由多个二维纳米片组成。通过对各种反应因素的调控分析，系统地探讨了这种花状结构的自组装形成机理。Ni/Mn LDHs微球在1 A·g-1时的最佳电容值为1379 F·g-1。和频产生光谱和电荷存储行为机理分析进一步表明，一个良好的电容构成确实依赖于活性位点（不同的进料比）和表面积（不同的建筑特征）的协同效应。此外，利用这些微球和活性炭分别作为正负电极材料组装了一种新型的柔性全固态非对称超级电容器，其上级电容值为393 F·g-1（1 A·g-1），能量密度和功率密度分别为131.17 Wh·kg-1和1.45 KW·kg-1，具有良好的循环寿命（在50 mV·s-1下循环5000次后仍保持75.1%以上）。总体而言，本工作为下一代柔性能源器件的发展提供了重要的前景和深刻的理解。
In this study, Ni/Mn layered double hydroxides (LDHs) microspheres with three-dimensional flower-like hierarchical structure are fabricated by a large-scale and self-assembled chemical coprecipitation strategy (at 55 °C under normal pressure). In each integrated microsphere, the petals consist of ultrathin two-dimensional nanosheets. The self-assembly formation mechanism of this flower-like construction is systematically investigated according to the analysis results from the regulation of various reaction factors. The Ni/Mn LDHs microspheres show an optimal capacitance value as high as 1379 F·g–1at 1 A·g–1. Sum frequency generation spectroscopy and charge storage behavior mechanism analysis further demonstrate that a favorable capacitive constitution is indeed dependent on the synergistic effect of active sites (different feed ratios) and surface area (different architectural features). Moreover, a novel flexible all-solid-state asymmetric supercapacitor is assembled by exploiting these microspheres and active carbon as positive and negative electrode materials respectively, which exhibits a superior capacitance value of 393 F·g–1(1 A·g–1) and energy and power density of 131.17 Wh·kg–1and 1.45 KW·kg–1with favorable cyclic life (remains over 75.1% after 5000 cycles under 50 mV·s–1), respectively. Overall, this work provides a significant prospect and deep understanding for the development of the next generation of flexible energy devices.