Preparation And Characterization Of Ni, Co Based On Ni-foam Electrode Materials

The development of clean and environment-friendly energy resources is considered to be one the most important issues in the 21 st century. It is urgent to fabricate some reliable electrochemical energy storage devices such as rechargeable batteries, supercapacitors and fuel cells. In this thesis, we fabricated two nanowires-ZIF-67 electrode materials.（1） Using a simple hydrothermal method, we synthesized Co₃O₄ nanowires on Ni-foam substrate. Based on the large porous structure, the growth of Co₃O₄ nanowires increases specific surface area, which improves the specific capacitance of electrode material. Through the electrochemical tests, the specific capacitance reaches at 1074 F·cm-2 at a current density of 2mA·cm-2.（2） Further, based on Co₃O₄/Ni-foam composite, the ZIF-67 polyhedral is synthesized in situ on its surface. Especially, the specific capacitance arrives at 3702F·cm-2 at current density of 2mA·cm-2. After 10000 cycles, the specific capacity remains of more than 91% of the original capacity.（3） MnO₂ nanowires/Co₃O₄ composites are successfully synthesized and it shows a high specific capacity, good cycling stability and high rate capability.