Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran.
Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran; Institute for Nanoscience and Technology, Sharif University of Technology, Tehran, Iran.
J Colloid Interface Sci. 2019 Apr 15;542:325-338. doi: 10.1016/j.jcis.2019.02.019. Epub 2019 Feb 7.
Wire-shaped micro-supercapacitors attracted extensive attentions in next-generation portable and wearable electronics, due to advantages of miniature size, lightweight and flexibility. Herein, NiMoO nanorods supported on Ni film coated Cu wire are successfully fabricated thorough direct deposition of Ni film onto Cu wire as the conductive substrate, followed by growth of the NiMoO nanorods on Ni film coated Cu wire substrate by means a hydrothermal annealing process. The prepared 3D, porous electrode demonstrates extremely high areal specific capacitance of 12.03F cm at the current density of 4 mA cm and retained capacitance of 8.23 F cm at a much higher current density of 80 mAcm. The electrode, also, shows an excellent cycling stability with capacitance retention of 99.3% after 3000 cycles. The superior electrochemical performance can be attributed to the high area surface, low contact resistance between NiMoO nanorods and Cu wire current collector and presence of a 3D and porous structure provides many electroactive sites and sufficient open space for easy diffusion of the electrolyte ions during redox reactions. Benefiting from their structural features, a fiber shaped asymmetric micro-supercapacitor based on NiMoO/Ni film/Cu wire as the positive electrode and carbon fiber coated with reduced graphene oxide as the negative electrode is assembled. The fabricated fiber device presents a wide potential window between 0 and 1.7 V and exhibits high specific capacitance of 0.504F cm (38.8F cm) at a current density of 4.8 mA cm with a high energy density of 202 µWh cm (15.6 mWh cm) at a power density of 4050 µW cm (313 mWh cm). The energy density retains 124 µWh cm (9.54 mWh cm) when the power density is increased to 13530 µW cm (1040.73 mWh cm). In addition, the asymmetric device exhibits an outstanding cycling stability (98.5% capacitance retention after 1000 consecutive cycles) and good mechanical stability. Therefore, this work suggested the promising potential of NiMoO nanorods supported on Ni film coated Cu wire as an advanced electrode material for construction of flexible and portable next-generation energy storage micro-devices with superior electrochemical performances.
金属丝型微型超级电容器由于其尺寸小、重量轻和柔韧性等优点，在下一代可穿戴和便携式电子产品中引起了广泛关注。在此，通过直接在作为导电基底的 Cu 线上沉积 Ni 膜，然后在 Ni 膜包覆的 Cu 线上通过水热退火工艺生长 NiMoO 纳米棒，成功制备了 NiMoO 纳米棒负载在 Ni 膜包覆的 Cu 线上。所制备的 3D 多孔电极在电流密度为 4 mA cm 时表现出极高的面比电容 12.03 F cm，在更高的电流密度 80 mA cm 时保留电容 8.23 F cm。该电极还具有出色的循环稳定性，经过 3000 次循环后电容保持率为 99.3%。优异的电化学性能可归因于高面积比、NiMoO 纳米棒与 Cu 线电流集电器之间的低接触电阻以及 3D 多孔结构的存在，为氧化还原反应中电解质离子的扩散提供了许多电活性位点和足够的开放空间。得益于其结构特点，以 NiMoO/Ni 膜/Cu 线作为正极，碳纤维负载还原氧化石墨烯作为负极，组装了一种纤维状不对称微型超级电容器。所制备的纤维器件在 0 至 1.7 V 的宽电位窗口内表现出高比电容 0.504 F cm（38.8 F cm），在电流密度为 4.8 mA cm 时具有高能量密度 202 µWh cm（15.6 mWh cm），在功率密度为 4050 µW cm（313 mWh cm）时具有高能量密度。当功率密度增加到 13530 µW cm（1040.73 mWh cm）时，能量密度仍保持在 124 µWh cm（9.54 mWh cm）。此外，该非对称器件还表现出出色的循环稳定性（1000 次连续循环后电容保持率为 98.5%）和良好的机械稳定性。因此，这项工作表明 NiMoO 纳米棒负载在 Ni 膜包覆的 Cu 线上作为一种先进的电极材料，具有构建具有优异电化学性能的柔性和便携式下一代储能微器件的巨大潜力。
