Zhang Rongrong, Tu Qian, Li Xianran, Sun Xinyu, Liu Xinghai, Chen Liangzhe
School of Electronic Information Engineering, Jingchu University of Technology, Jingmen 448000, China.
Research Center of Graphic Communication, Printing and Packaging, Wuhan University, Wuhan 430079, China.
Nanomaterials (Basel). 2022 Jun 28;12(13):2216. doi: 10.3390/nano12132216.
Although it is one of the promising candidates for pseudocapacitance materials, Ni(OH) is confronted with poor specific capacitance and inferior cycling stability. The design and construction of three-dimensional (3D) nanosphere structures turns out to be a valid strategy to combat these disadvantages and has attracted tremendous attention. In this paper, a 3D α-Ni(OH) nanosphere is prepared via a facile and template-free dynamic refluxing approach. Significantly, the α-Ni(OH) nanosphere possesses a high specific surface area (119.4 m/g) and an abundant porous structure. In addition, the as-obtained α-Ni(OH) electrodes are investigated by electrochemical measurements, which exhibit a high specific capacitance of 1243 F/g at 1 A/g in 6 M KOH electrolyte and an acceptable capacitive retention of 40.0% after 1500 charge/discharge cycles at 10 A/g, which can be attributed to the sphere's unique nanostructure. Furthermore, the as-assembled Ni(OH)-36//AC asymmetric supercapacitor (ASC) yields a remarkable energy density of 26.50 Wh/kg, with a power density of 0.82 kW/kg. Notably, two ASCs in series can light a 2.5 V red lamp sustainably for more than 60 min, as well as power an LED band with a rated power of 25 W. Hence, this 3D α-Ni(OH) nanosphere may raise great potential applications for next-generation energy storage devices.
尽管氢氧化镍是赝电容材料中很有前景的候选材料之一，但它面临着比电容低和循环稳定性差的问题。三维（3D）纳米球结构的设计与构建被证明是克服这些缺点的有效策略，并引起了极大关注。本文通过一种简便的无模板动态回流法制备了3D α-氢氧化镍纳米球。值得注意的是，α-氢氧化镍纳米球具有高比表面积（119.4 m²/g）和丰富的多孔结构。此外，通过电化学测量对所制备的α-氢氧化镍电极进行了研究，在6 M氢氧化钾电解液中，其在1 A/g电流密度下展现出1243 F/g的高比电容，在10 A/g电流密度下经过1500次充放电循环后具有40.0%的可接受电容保持率，这可归因于该纳米球独特的纳米结构。此外，所组装的氢氧化镍-36//活性炭不对称超级电容器（ASC）具有26.5 Wh/kg的显著能量密度和0.82 kW/kg的功率密度。值得注意的是，两个串联的ASC能够持续点亮一盏2.5 V的红灯超过60分钟，还能为一个额定功率为25 W的LED灯带供电。因此，这种3D α-氢氧化镍纳米球可能在下一代储能装置中具有巨大的潜在应用。
