基于 MOFs 的碳纳米棒和石墨烯纳米带负载的 Ni-Co 层状双氢氧化物用于超级电容器。

Ni-Co layered double hydroxide on carbon nanorods and graphene nanoribbons derived from MOFs for supercapacitors.

机构信息

College of Materials Science and Engineering, Sichuan University, Chengdu 610064, China.

出版信息

Dalton Trans. 2018 Jul 3;47(26):8706-8715. doi: 10.1039/c8dt01882k.

Abstract

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).

摘要

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%）。