Preparation Of Cobalt (Nickel) Molybdate Cathode Material And Polyaniline Activated Carbon Assembled Asymmetric Device

Supercapacitors,also called electrochemical capacitors,are widely used in transportation,industrial production and other fields because of their high power density and long service life.In the capacitor,the electrode material is the key to determine the main performance indicators of the capacitor.The in-situ growth of the active material on the nickel foam current collector is a common method for constructing a capacitor electrode material,and has the advantages of being free of binders.However,there is a 5-10 nm natural oxide layer on the surface of the foamed nickel.The natural oxide layer has low conductivity.High interface contact resistance are formed when it used as a current collector to construct the active materials such as metal molybdate.The oxides/oxides affecting electrochemical performance of metal molybdate.Based on this,this paper introduces graphene to reduce the interfacial contact resistance,and prepares a transition metal molybdate electrode with high theoretical capacity based on the foamed nickel deposited with highly conductive graphene as the substrate,and systematically evaluates the electrochemical performance.Then,a highly nitrogen-rich polyaniline derivative carbon was prepared as a negative electrode material,and a high-performance asymmetric supercapacitor was constructed,and some significant research results were obtained.The specific research contents are as follows:1.The CoMoO₄/GE/NF and CoMoO₄/NF were constructed by hydrothermal method based on graphene-coated nickel foam/graphene?NF/GE?and nickel foam?NF?.The results of electrochemical performance show that the introduction of graphene can effectively improve the interface between CoMoO₄ and the current collector,thus improving the electrochemical performance of the active material.When the current density is 1 A g^-1,the specific capacity of CoMoO₄/GE/NF is 775 F g^-1,which is higher than that of CoMoO₄/NF(579 F g^-1).After 3000 cycles of 3 A g^-1current density,the CoMoO₄/GE/NF still has a capacity retention rate of 89.3%,much higher than the CoMoO₄/NF capacity retention rate of46.5%.2.The polyaniline derivative carbon?for active polyamine derived carbon,APDC?was prepared by self-polymerization,high-temperature carbonization and KOH activation method using aniline monomer as raw material and ammonium persulfate as polymerization initiator.The CoMoO₄/GE/NF is positive,APDC/NF is negative,and the asymmetrical capacitor device is assembled with a power density of 369.9 W kg^-11 and an energy density of 27.1 Wh kg^-1.The cyclic performance test results show that the asymmetric capacitor device is After3000 cycles of current density of 1 A g^-1,the specific capacity retention rate can still reach over 111%,showing good cycle stability.The same method can also be used to prepare NiMoO₄ electrode material to improve its electrochemical performance.