Liu Zhiqiang, Li Aihua, Qiu Yanling, Zhao Qingyu, Zhong Yuxue, Cui Liang, Yang Wenrong, Razal Joselito M, Barrow Colin J, Liu Jingquan
College of Materials Science and Engineering, Institute for Graphene Applied Technology Innovation, Qingdao University, Qingdao 266071, China.
College of Materials Science and Engineering, Linyi University, Linyi, 276000 Shandong, China.
J Colloid Interface Sci. 2021 Jun 15;592:455-467. doi: 10.1016/j.jcis.2021.02.011. Epub 2021 Feb 7.
In this work, MgCoO@NiMn layered double hydroxide (LDH) core-shell structured nanocomposites on Ni foam (NF) are synthesized by facile hydrothermal and calcination methods. MgCoO/NF is synthesized first via a hydrothermal reaction and annealing treatment, and then utilized to prepare MgCoO@NiMn-LDH/NF core-shell structured nanocomposites via the second hydrothermal process. It is found that the MgCoO@NiMn-LDH/NF nanocomposite prepared from 6 h hydrothermal reaction (MC@NM-LDH-2) exhibits an excellent specific capacitance of 3757.2 F g (at 1 A g). Moreover, a high capacitance retention (86.9% after 6000 cycles) and a low internal resistance (Rs) (0.565 Ω) can be achieved. Furthermore, an all-solid-state asymmetric supercapacitor (ASC) is assembled using MgCoO@NiMn-LDH/NF-2 as positive electrode and activated carbon (AC) as negative electrode. The as-fabricated MgCoO@NiMn-LDH/NF-2//AC ASC shows a high energy density of 62.33 Wh kg at 750 W kg. Meanwhile, the MgCoO@NiMn-LDH/NF-2//AC ASC device possesses an outstanding cycling stability of 93.7% retention of the initial capacitance after 6000 cycles and three ASC devices connected in series can light up a LED bulb for 15 min. Our results manifest that these core-shell structure MgCoO@NiMn-LDH nanocomposites could envision huge potential application in energy storage devices.
在本工作中，通过简便的水热和煅烧方法在泡沫镍（NF）上合成了MgCoO@NiMn层状双氢氧化物（LDH）核壳结构纳米复合材料。首先通过水热反应和退火处理合成MgCoO/NF，然后利用其通过第二次水热过程制备MgCoO@NiMn-LDH/NF核壳结构纳米复合材料。结果发现，由6小时水热反应制备的MgCoO@NiMn-LDH/NF纳米复合材料（MC@NM-LDH-2）在1 A g下表现出3757.2 F g的优异比电容。此外，还可实现高电容保持率（6000次循环后为86.9%）和低内阻（Rs）（0.565Ω）。此外，以MgCoO@NiMn-LDH/NF-2作为正极、活性炭（AC）作为负极组装了全固态不对称超级电容器（ASC）。所制备的MgCoO@NiMn-LDH/NF-2//AC ASC在750 W kg下显示出62.33 Wh kg的高能量密度。同时，MgCoO@NiMn-LDH/NF-2//AC ASC器件具有出色的循环稳定性，6000次循环后初始电容保持率为93.7%，三个串联的ASC器件可为一个LED灯泡供电15分钟。我们的结果表明，这些核壳结构的MgCoO@NiMn-LDH纳米复合材料在储能器件中具有巨大的潜在应用前景。
