Three-Dimensional Hierarchical NixCo1–<i>xO/NiyCo2–<i>yP@C Hybrids on Nickel Foam for Excellent Supercapacitors
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- 作者：Yubo Shao ; Yongqing Zhao ; Hua Li ; Cailing Xu
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2016
- 出版时间：December 28, 2016
- 年：2016
- 卷：8
- 期：51
- 页码：35368-35376
- 全文大小：654K
- ISSN：1944-8252
文摘
Active materials and special structures of the electrode have decisive influence on the electrochemical properties of supercapacitors. Herein, three-dimensional (3D) hierarchical Ni<i>xi>Co1–<i>xi>O/Ni<i>yi>Co2–<i>yi>P@C (denoted as NiCoOP@C) hybrids have been successfully prepared by a phosphorization treatment of hierarchical Ni<i>xi>Co1–<i>xi>O@C grown on nickel foam. The resulting NiCoOP@C hybrids exhibit an outstanding specific capacitance and cycle performance because they couple the merits of the superior cycling stability of Ni<i>xi>Co1–<i>xi>O, the high specific capacitance of Ni<i>yi>Co2–<i>yi>P, the mechanical stability of carbon layer, and the 3D hierarchical structure. The specific capacitance of 2638 F g–1 can be obtained at the current density of 1 A g–1, and even at the current density of 20 A g–1, the NiCoOP@C electrode still possesses a specific capacitance of 1144 F g–1. After 3000 cycles at 10 A g–1, 84% of the initial specific capacitance is still remained. In addition, an asymmetric ultracapacitor (ASC) is assembled through using NiCoOP@C hybrids as anode and activated carbon as cathode. The as-prepared ASC obtains a maximum energy density of 39.4 Wh kg–1 at a power density of 394 W kg–1 and still holds 21 Wh kg–1 at 7500 W kg–1.