Electrodeposition of three dimensional-porous Ni/Ni(OH) 2 hierarchical nano composite via etching the Ni/Zn/Ni(OH) 2 precursor as a high performance pseudocapacitor

We have electrochemically synthesized 3D-porous micro-nano Ni/Ni(OH)2 hierarchical nanocomposites with improved supercapacitive performance. Firstly, the 3D-porous micro-nano Ni/Zn hierarchical nanoplatelets were constructed in a two-step gas bubble dynamic template deposition method as a scaffold with the open porous structure and extra high surface area for the subsequent electrodeposition of Ni(OH)2 nanostructures. Then the zinc were removed from the prepared 3D Ni/Zn/Ni(OH)2 nanocomposite via performing an etching process. The resulted 3D-porous micro-nano Ni/Ni(OH)2 hierarchical nanocomposites showed a high areal capacitance of 2.18 F cm−2 (2400 F g−1) at the current density of 1.12 mA cm−2 (1.25 A g−1) which is so higher than the measured amount for the prepared 3D-Ni/Ni(OH)2 nanocomposites by directly deposition of nickel hydroxide on the synthesized 3D nickel foam. In addition, the prepared nanocomposite films exhibit the great cycling stability. The capacitance retention was about 100.012% after performing 1000 charge–discharge cycles, and decreases only about 1.3% after the 2000th cycle.