Wang Xuan Liang, Jin En Mei, Chen Jiasheng, Bandyopadhyay Parthasarathi, Jin Bo, Jeong Sang Mun
Department of Chemical Engineering, Chungbuk National University, 1 Chungdae-ro, Seowon-gu, Cheongju 28644, Chungbuk, Korea.
Key Laboratory of Automobile Materials, Ministry of Education, and College of Materials Science and Engineering, Jilin University, Changchun 130022, China.
Nanomaterials (Basel). 2021 Dec 23;12(1):34. doi: 10.3390/nano12010034.
NiS nanowires were synthesized in situ using a one-pot hydrothermal reaction on Ni foam (NF) for use in supercapacitors as a positive electrode, and various contents (0.3-0.6 mmol) of Co(OH) shells were coated onto the surfaces of the NiS nanowire cores to improve the electrochemical properties. The NiS nanowires were uniformly formed on the smooth NF surface, and the Co(OH) shell was formed on the NiS nanowire surface. By direct NF participation as a reactant without adding any other Ni source, NiS was formed more closely to the NF surface, and the Co(OH) shell suppressed the loss of active material during charging-discharging, yielding excellent electrochemical properties. The Co(OH)-NiS/Ni electrode produced using 0.5 mmol Co(OH) (Co-NiS/Ni) exhibited a high specific capacitance of 1837 F g (16.07 F cm) at a current density of 5 mA cm, and maintained a capacitance of 583 F g (16.07 F cm) at a much higher current density of 50 mA cm. An asymmetric supercapacitor (ASC) with Co(OH)-NiS and active carbon displayed a high-power density of 1036 kW kg at an energy density of 43 W h kg with good cycling stability, indicating its suitability for use in energy storage applications. Thus, the newly developed core-shell structure, Co(OH)-NiS, was shown to be efficient at improving the electrochemical performance.
通过在泡沫镍（NF）上进行一锅水热反应原位合成硫化镍纳米线，用作超级电容器的正极，并在硫化镍纳米线芯表面包覆不同含量（0.3 - 0.6 mmol）的氢氧化钴壳层以改善其电化学性能。硫化镍纳米线均匀地形成在光滑的泡沫镍表面，氢氧化钴壳层则形成在硫化镍纳米线表面。通过直接让泡沫镍作为反应物参与反应，无需添加任何其他镍源，硫化镍更紧密地在泡沫镍表面形成，并且氢氧化钴壳层抑制了充放电过程中活性材料的损失，从而产生优异的电化学性能。使用0.5 mmol氢氧化钴制备的氢氧化钴 - 硫化镍/镍电极（Co - NiS/Ni）在电流密度为5 mA/cm²时表现出1837 F/g（16.07 F/cm²）的高比电容，在高达50 mA/cm²的电流密度下仍保持583 F/g（16.07 F/cm²）的电容。由氢氧化钴 - 硫化镍和活性炭组成的非对称超级电容器（ASC）在能量密度为43 W·h/kg时表现出1036 kW/kg的高功率密度，且具有良好的循环稳定性，表明其适用于储能应用。因此，新开发的核壳结构氢氧化钴 - 硫化镍在改善电化学性能方面显示出高效性。
