| Supercapacitors,as a new energy storage and conversion device,have higher power density and longer cycle life than lithium batteries,and can be used in consumer electronics,new energy vehicles and other fields.However,because the energy density of ultracapacitors is not ideal enough to achieve large-scale commercialization,the development of high energy density,high power performance of ultracapacitors has become a research hotspot.Electrode is the most important component of ultracapacitor and the choice of electrode material is the key factor to determine the performance of ultracapacitor.The transition metal?such as nickel,cobalt,manganese,etc.?oxide/hydroxide has been proved to be a promising electrode material for supercapacitors due to its abundant reserves,low cost and high theoretical capacity.This paper study the three dimensional self-supporting transition metal oxide/sulfur/hydroxyl array base core/shell structure super capacitor electrode material has the advantages of this materials at the same time expanding the specific surface area and active site,enhances the reaction in the process of chemical stability,through core/shell material of synergy between improves the electrochemical properties of this material.At the same time,the self-supporting electrode material can be used directly as the electrode of supercapacitor.The specific research contents of this paper are as follows:?i?NiMn LDH nanosheet clad CoMn2O4 nanowires CoMn2O4@NiMn LDH three-dimensional core/shell array composite electrode material was prepared on porous nickel foam by hydrothermal and calcining method.XRD,XPS,TEM,SEM and other characterization methods were used to analyze the phase and microstructure of the composite electrode materials and the supercapacitor properties of the composite electrode materials were tested.The results show that,when the current density is 1 A g-1 and 20 A g-1,the specific capacitance of the composite electrode material can reach 313 mAh g-1 and 127.8 mAh g-1,and has good cyclic stability.Supercapacitor devices with CoMn2O4@NiMn LDH as the positive electrode and activated carbon as the negative electrode have an energy density up to 118.8 Wh Kg-1,and successfully lit the series LED lamp.?ii?CoMn2O4@Ni3S2 three-dimensional self-supporting core/shell array electrode materials were successfully prepared by hydrothermal,calcining and electrochemical deposition.The material was characterized by XRD,XPS,TEM,SEM and other characterization methods.Electrochemical test results show that the electrode material has excellent multiplier performance and cyclic stability.when the current density is 1 A g-1 and 20 A g-1,the specific capacitance of the composite electrode material can reach 192.2 mAh g-1 and 27.8 mAh g-1 and the retention rate of specific capacity was 90.2%at the current density of 10 A g-1 for 10000 cycles.At the same time,when the power density of the corresponding supercapacitor device is1030 W Kg-1,the energy density can reach 51.2 Wh·Kg-1,and it can provide energy for the motor to turn.?iii?The precursor of ZIF-67 was grown in situ on carbon cloth by self-assembly method,and leaf-like NiCo LDH was obtained by nickel sulfate etching.Then,flake MnO2 was deposited on the surface of leaf-like NiCo LDH by hydrothermal method,and the three-dimensional self-supporting core-shell composite electrode material NiCo LDH@MnO2 was successfully prepared.The phase composition,microstructure and electrochemical properties of composite electrode materials were investigated.The results show that the specific capacitance of NiCo LDH@MnO2 can reach 313.6 mAh g-1 when the current density is 1 A g-1.With NiCo LDH@MnO2 as the positive electrode material and activated carbon as the negative electrode material,the supercapacitor has an energy density up to 125.5 Wh Kg-1.The specific capacitance retention of the supercapacitor is 84.7%after 10000 cycles,which indicates that the supercapacitor has good cyclic stability. |
PDF Full Text Request