Study On The Construction And Supercapacitor Properties Of Copper-Manganese-Tin Transition Metal Sulfides And Their Composites

With the development of economy and technology,there is an increasing demand for energy storage devices with high electrical capacity,high safety performance and high environmental protection performance.Compared with traditional batteries,supercapacitors have the advantages of fast charging rate and high capacitance,making them an excellent energy storage device that meets people’s needs.Generally speaking,electrode materials are the core component of supercapacitors,and excellent electrochemical performance often comes from the highly active substances in electrode materials.Therefore,developing electrode materials with excellent electrochemical performance is of great significance for improving the performance of supercapacitors.In this paper,copper-manganese-tin transition metal sulfides and their composites were prepared by hydrothermal and solvothermal methods.The main research contents are summarized as follows:（1）Cu₂Mn Sn S₄（CMTS）transition metal sulfides with irregular rice-like two-dimensional nanocondensed structure were synthesized by an efficient and facile one-step solvothermal method.Thanks to the rice-like nanostructure on the surface of material and the synergistic interaction between Cu,Mn,Sn and S elements,CMTS has a high specific capacitance of 1117.7 F g^-1 at a current density of 0.8 A g^-1.At a current density of 10A g^-1,the capacitance still maintains 82.3%cyclic stability after 10000charge-discharges.The excellent electrochemical properties indicate that CMTS has excellent Faraday reaction and charge storage properties,and is expected to become a promising electrode material for supercapacitors.This work not only provides an effective strategy for the preparation of electrode materials,but also provides a new approach for the design of high stability energy storage devices.（2）Ni Cl₂·6H₂O and Co Cl₂·6H₂O as raw materials,needle-like nano NiCo precursor material was prepared by a one-step hydrothermal method,and then added to Cu-Mn-Sn transition metal sulfides solution.The condensed NiCo/Cu-Mn-Sn transition metal sulfides（NiCo/CMTS）nanoparticles were synthesized using secondary solvent thermal control heating time.The structural characterization of the materials showed that the Cu-Mn-Sn transition metal sulfides are distributed on the surface of NiCo precursor nanosheets,accelerating the rate of charge transfer during their charging and discharging processes.When the current density is 1 m A cm^-2,the specific capacity of the NiCo/CMTS composite material can reach 1419.1 m F cm^-2.In addition,the composite electrode has good cycling stability,still exhibiting 97.0%coulombic efficiency and 69.3%capacitance retention after 2000 cycles.The results of this study indicate that NiCo/CMTS composite effectively improves the capacitance of NiCo precursor,and is an ideal electrode material that is expected to be widely used in the field of energy storage devices.（3）Based on the structural stability,flexibility and high conductivity,graphene nanosheets（GN）have shown broad application prospects in the field of supercapacitors.The Co-MOF/GN/Cu-Mn-Sn transition metal sulfide（Co-MOF/CMTS@GN）granular structure derived from GN interpenetrating Co-MOF was synthesized by hydrothermal method.This stable structure not only improves the charge transfer ability but also significantly increases the specific capacitance.Test results show Co-MOF/CMTS@GN electrode exhibits a high specific capacitance of2677.8 m F cm^-2 at a current density of 1 m A cm^-2,and due to the activation of the reaction site,it can maintain a coulombic efficiency of 108.0%after2000 consecutive charges and discharges at a current density of 20 m A cm^-2,indicating its excellent electrochemical performance,providing a new opportunity for the development of energy storage devices.