Preparation And Electrochemical Properties Of Cu-Ni Nanorod Arrays At Room Temperature

Energy storage devices are becoming more important in daily life,such as lead-acid batteries,dry batteries,and supercapacitors（SC）.Among them SC has the characteristics of high power density and safety,which has gradually become a research hotspot.In the process of SC research and development,we mainly need to solve the problems of electrode materials such as poor conductivity,low rate performance and short cycle life.Transition metal oxide（TMO）is a potential SC electrode material and its preparation method is relatively simple.The rapid redox reaction between metal cations and electrolyte would occur on the surface or bulk phase of materials,which results in higher theoretical energy density.It is expected to prepare high-performance electrode materials suitable for practical application by in-situ growth of transition metal oxides on copper foam（CuF）substrate.The main research contents are as follows:（1）First,the clean CuF substrate was oxidized in one step by the solution method to grow Cu（OH）₂ nanorod arrays on the surface,then Ni element was added to the electrode material by the simple solution method,and finally the electrode material was activated by the electrochemical oxidation method to obtain 3D CuNi-hybrid nanorod array electrode.The whole preparation process needed to be carried out at room temperature,which can greatly reduce energy consumption and time compared with solvothermal reaction,annealing process and other synthesis methods.The electrode prepared in this way not only has a large specific surface area,but also has good charge storage performance,which is better than that of single copper or nickel.The specific capacity of CuNi-hybrid/CuF nanorod array electrode material reaches 2420 m C·cm^-2 when the current density is 2 m A·cm^-2 in 1M KOH solution.（2）Construction of HSC with CuNi-hybrid as positive electrode and activated carbon（AC）as negative electrode.The two electrode materials needed to meet the principle of charge balance,and the corresponding voltages of positive electrode and negative electrode materials were different,so as to broadened the voltage window,and explored its practical value as a device.Because the positive electrode material was a structure grown in situ and has strong adhesion,the use of binder and conductive agent was avoided.Electrochemical test of the capacitor shows that the specific capacitance can reach 2050 m C·cm^-2 when the current density is 5 m A·cm^-2,the energy density is 420μWh·cm^-2,and the power density is 2297μW·cm^-2.After1000 cycles of stability tests,it can be maintained at 82%of the initial value,showing certain application value.