Studies On Preparation And Properties Of Nickel-cobalt Based MOF As Supercapacitor Electrode

Supercapacitors have many advantages,such as high power density,high specific capacity,long cycle life and environmental protection.They have broad application prospects in many fields.Electrode material is the core part of supercapacitor and plays an important role in its performance.As a new material,metal organic frameworks(MOF)have many advantages,such as large specific surface area,adjustable channels and functional diversity.Nickel and cobalt elements are cheap and easy to obtain,and have high theoretical specific capacity.Nickel and cobalt based MOF materials are expected to become high performance electrode materials.In this paper,low cost and high performance Ni-Co MOF materials were prepared by simple hydrothermal method.The structure,morphology and electrochemical properties of the materials were characterized,and the properties of the assembled all-solid-state devices were studied.The main research contents are as follows:(1)Nickel-cobalt coordination polymer was prepared by hydrothermal method,and the activated structure was transformed into Ni/Co-MOF.The electrochemical tests show that Ni/Co-MOF has excellent electrochemical properties.The Ni/Co-MOF exhibits a high specific capacity of 833C/g at 0.5A/g and a very good cycling stability is achieved after 5000 cycles.(2)All-solid-state devices based on Ni/Co-MOF exhibit excellent electrochemical performance.A high specific capacitance of 172.7F/g in a large potential window of1.8V has been achieved,which corresponds to a high specific energy of 77.7Wh/kg.The devices also exhibit very good flexibility under bending and folding conditions with no obvious capacitance change.Meanwhile,the influence of temperature on the performance of the all-solid-state devices has been evaluated.(3)The ternary mixed metal Ni/Co/Mn-MOF was prepared.The electrochemical test showed that the specific capacity was 736.6C/g at the current density of 0.5A/g.All-solid-state devices based on Ni/Co/Mn-MOF exhibit good electrochemical performance with a specific capacity of 153.5F/g in potential window of 1.6V.