Anion Exchange of Ni-Co Layered Double Hydroxide (LDH) Nanoarrays for a High-Capacitance Supercapacitor Electrode: A Comparison of Alkali Anion Exchange and Sulfuration

作者：Zou, Wenru; Guo, Wenxin; Liu, Xinyi; Luo, Yunli; Ye, Qinglan; Xu, Xuetang^*; Wang, Fan^*

来源：Chemistry - A European Journal, 2018, 24(72): 19309-19316.

DOI：10.1002/chem.201804218

• anions
• coulombic efficiency
• electrochemistry
• ion exchange
• sulfuration
• supercapacitors

A facile and new anion exchange process is presented, which involves the conversion of NiCo-CO3 layered double hydroxide (LDH) nanosheet arrays in an alkaline solution. The anion exchange between CO32- and OH- results in the construction of a reservoir for OH- anions, and the decoration of thin nanoflakes on the surface of nanosheets effectively enlarges the surface area of NiCo LDH nanoarrays. The capacitance of the as-soaked NiCo LDH nanoarrays electrode increases from 1.78 F cm(-2) (684 F g(-1)) to 6.22 F cm(-2) (2391 F g(-1)) at 2 mA cm(-2) after soaking for 12 h. Moreover, the soaked NiCo-OH LDH electrode exhibits an enhanced rate capacity, high coulombic efficiency, and good cycling stability compared with the Ni-Co-S nanosheet electrode synthesized through a hydrothermal sulfuration process. The as-assembled all-solid-state NiCo LDH//active carbon asymmetric supercapacitor shows a maximum energy density of 83.4 W h kg(-1) at a power density of 1066 W kg(-1).

• 出版日期2018-12-20
• 单位广西大学