College of Materials Science and Engineering, Sichuan University, Chengdu 610064, China.
Dalton Trans. 2018 Jul 3;47(26):8706-8715. doi: 10.1039/c8dt01882k.
In this study, carbon nanorods (CNR) and graphene nanoribbons (GNR) derived from metal-organic frameworks (MOFs) were first prepared by solvothermal method. Then, Ni-Co layered double hydroxide (LDH)/CNR and LDH/GNR composite materials for supercapacitors were synthesized using a facile co-precipitation method. With the help of GNR, the Ni-Co LDH/GNR composite material showed great specific capacity (1765 F g-1), rate performance (68% capacity retention when current density increased from 1 to 20 A g-1) and cycling stability (83% capacity retention after 2000 charge-discharge cycles at 5 A g-1). Furthermore, an asymmetric supercapacitor (ASC) with Ni-Co LDH/GNR as positive and activated carbon (AC) as negative electrodes was fabricated. The ASC device delivered a high energy density of 25.4 W h kg-1 at power density of 749 W kg-1 and exhibited excellent cycling stability (96% specific capacity retention after 5000 cycles).
在这项研究中，首先通过溶剂热法制备了源自金属有机骨架（MOFs）的碳纳米棒（CNR）和石墨烯纳米带（GNR）。然后，通过简便的共沉淀法合成了用于超级电容器的 Ni-Co 层状双氢氧化物（LDH）/CNR 和 LDH/GNR 复合材料。在 GNR 的帮助下，Ni-Co LDH/GNR 复合材料表现出了巨大的比容量（1765 F g-1）、倍率性能（当电流密度从 1 增加到 20 A g-1 时，保留 68%的容量）和循环稳定性（在 5 A g-1 下经过 2000 次充放电循环后，保留 83%的容量）。此外，还制备了以 Ni-Co LDH/GNR 为正极、活性炭（AC）为负极的不对称超级电容器（ASC）。该 ASC 器件在 749 W kg-1 的功率密度下表现出 25.4 W h kg-1 的高能量密度，并且具有出色的循环稳定性（经过 5000 次循环后，比容量保留 96%）。
