Department of Applied Chemistry, School of Science, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University , Xi'an 710049, People's Republic of China.
ACS Appl Mater Interfaces. 2017 May 31;9(21):17890-17896. doi: 10.1021/acsami.7b02693. Epub 2017 May 17.
Nickel hydroxide (Ni(OH)) has been regarded as a potential next-generation electrode material for supercapacitor owing to its attractive high theoretical capacitance. However, practical application of Ni(OH) is hindered by its lower cycling life. To overcome the inherent defects, herein we demonstrate a unique interconnected honeycomb structure of g-CN and Ni(OH) synthesized by an environmentally friendly one-step method. In this work, g-CN has excellent chemical stability and supports a perpendicular charge-transporting direction in charge-discharge process, facilitating electron transportation along that direction. The as-prepared composite exhibits higher specific capacities (1768.7 F g at 7 A g and 2667 F g at 3 mV s, respectively) compared to Ni(OH) aggregations (968.9 F g at 7 A g) and g-CN (416.5 F g at 7 A g), as well as better cycling performance (∼84% retentions after 4000 cycles). As asymmetric supercapacitor, g-CN@Ni(OH)//graphene exhibits high capacitance (51 F g) and long cycle life (72% retentions after 8000 cycles). Moreover, high energy density of 43.1 Wh kg and power density of 9126 W kg has been achieved. This attractive performance reveals that g-CN@Ni(OH) with honeycomb architecture could find potential application as an electrode material for high-performance supercapacitors.
氢氧化镍（Ni(OH)）因其高理论电容而被认为是超级电容器的一种有前途的下一代电极材料。然而，由于其较低的循环寿命，Ni(OH)的实际应用受到了阻碍。为了克服固有缺陷，本文通过一种环保的一步法，展示了一种独特的相互连接的 g-CN 和 Ni(OH)的蜂窝状结构。在这项工作中，g-CN 具有优异的化学稳定性，并在充放电过程中支持垂直的电荷输运方向，有利于沿该方向的电子输运。与 Ni(OH)聚集体（7 A g 下为 968.9 F g）和 g-CN（7 A g 下为 416.5 F g）相比，所制备的复合材料具有更高的比容量（7 A g 下分别为 1768.7 F g 和 3 mV s 下为 2667 F g），以及更好的循环性能（4000 次循环后保留率约为 84%）。作为非对称超级电容器，g-CN@Ni(OH)//graphene 表现出高电容（51 F g）和长循环寿命（8000 次循环后保留率为 72%）。此外，还实现了 43.1 Wh kg 的高能量密度和 9126 W kg 的高功率密度。这种吸引人的性能表明，具有蜂窝结构的 g-CN@Ni(OH)可以作为高性能超级电容器的电极材料得到广泛应用。
