Xin Chen, Ang Li, Musharavati Farayi, Jaber Fadi, Hui Li, Zalnezhad Erfan, Bae Sungchul, Hui Kwan San, Hui Kwun Nam
Department of Mechanical Convergence Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.
Department of Mechanical and Industrial Engineering, College of Engineering, Qatar University, Doha 2713, Qatar.
Nanomaterials (Basel). 2020 Mar 23;10(3):584. doi: 10.3390/nano10030584.
In this study, to fabricate a non-binder electrode, we grew nickel-cobalt sulfide (NCS) nanotubes (NTs) on a Ni foam substrate using a hydrothermal method through a two-step approach, namely in situ growth and an anion-exchange reaction. This was followed by the electrodeposition of double-layered nickel-cobalt hydroxide (NCOH) over a nanotube-coated substrate to fabricate NCOH core-shell nanotubes. The final product is called NCS@NCOH herein. Structural and morphological analyses of the synthesized electrode materials were conducted via SEM and XRD. Different electrodeposition times were selected, including 10, 20, 40, and 80 s. The results indicate that the NCSNTs electrodeposited with NCOH nanosheets for 40 s have the highest specific capacitance (SC), cycling stability (2105 Fg at a current density of 2 Ag), and capacitance retention (65.1% after 3,000 cycles), in comparison with those electrodeposited for 10, 20, and 80 s. Furthermore, for practical applications, a device with negative and positive electrodes made of active carbon and NCS@NCOH was fabricated, achieving a high-energy density of 23.73 Whkg at a power density of 400 Wkg.
在本研究中，为制备一种无粘结剂电极，我们采用水热法通过两步法，即在泡沫镍基底上生长硫化镍钴（NCS）纳米管（NTs），这两步分别是原位生长和阴离子交换反应。随后，在涂覆有纳米管的基底上进行双层氢氧化镍钴（NCOH）的电沉积，以制备NCOH核壳纳米管。在此，最终产物称为NCS@NCOH。通过扫描电子显微镜（SEM）和X射线衍射（XRD）对合成的电极材料进行了结构和形态分析。选择了不同的电沉积时间，包括10、20、400和80秒。结果表明，与电沉积10、20和80秒的情况相比，电沉积40秒的NCS纳米管与NCOH纳米片复合后具有最高的比电容（SC）、循环稳定性（在2 Ag电流密度下为2105 F/g）和电容保持率（3000次循环后为65.1%）。此外，为了实际应用，制备了一种由活性炭和NCS@NCOH制成的正负极器件，在400 W/kg的功率密度下实现了23.73 Wh/kg的高能量密度。
