NiCo-layered double hydroxide with cation vacancy defects for high-performance supercapacitors
NiCo-layered double hydroxide with cation vacancy defects for high-performance supercapacitors
复制标题
具有阳离子空位缺陷的NiCo层状双氢氧化物用于高性能超级电容器
DOI：
10.1016/j.electacta.2022.140143
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发表时间：
2022
影响因子：
6.6
通讯作者：
Chao Li
中科院分区：
文献类型：
--
作者：
Guangping Lei;Daokun Chen;Qibin Li;Hantao Liu;Qing Shi;Chao Li
Layered double hydroxides (LDHs) with high specific capacitances have proved to be promising electrode materials for supercapacitors. However, the drawbacks of their insulating nature and limited active sites hinder further capacity enhancement. Herein, the NiCo-LDH/NF with abundant cobalt ion vacancy defects (D-NiCo-LDH/NF) was synthesized based on the memory effect. Revealed by the density functional theory (DFT) calculations, the cobalt ion vacancy induces more active electrons to near the Fermi level, thus enhancing conductivity and accelerating charge transfer. Profiting from the optimized local electronic structure and more exposed active sites, the as-synthesizedd-NiCo-LDH/NF exhibits unexpected specific capacity of 361 mAhg−1and specific capacitance of 3200 Fg−1at the current density of 1 Ag−1, much higher than that of the pristine NiCo-LDH/NF electrode (282 mAhg−1and 2500 Fg−1at 1 Ag−1). Furthermore, assembled asymmetric supercapacitor (ASC) withd-NiCo-LDH/NF and activated carbon (AC) working as the positive electrode and negative electrode material, respectively, displays a superior energy density of 53 Wh kg−1under a power density of 752 W kg−1with outstanding cycle stability of 94.7% retention after 5000 cycles.
