Preparation Of Manganese-Cobalt Oxide/MXene Nanocomposites And Study Of Their Electrochemical Properties

With the increasing demand and consumption of energy year by year,the storage of traditional fossil energy on the earth is limited,and the burning of fossil energy will bring many problems such as greenhouse effect,air pollution,acid rain,etc.Therefore,it is urgent to develop renewable energy sources to replace traditional fossil energy and solve the energy crisis.MXene has a unique accordion-like structure,large specific surface area,remarkable electrical conductivity,and good chemical stability,making it an ideal candidate material for supercapacitor electrodes.Due to the large surface energy between the MXene layers,it is easy to stack between layers,and the interlayer energy storage field cannot be fully utilized.Therefore,increasing the interlayer spacing of MXene is a research focus for improving electrochemical performance.In this thesis,MXene is taken as the research object,and the intercalation of manganese cobalt oxide is used to investigate the effect on its electrochemical performance.The specific research contents are as follows:1.Preparation of MXene by HF etching.After the Al atomic layer in Ti₃Al C₂was peeled off with hydrofluoric acid（HF）,the Ti₃C₂（MXene）was synthesized.Electrodes were prepared by mixing the MXene with conductive agent and binder in a certain proportion to test its electrochemical performance.The specific capacitance of MXene was found to be 67.15 F g^-1at a current density of 1 A g^-1.2.MnO₂/MXene was prepared by the hydrothermal method.Using MnO₂as intercalation agent,the interlayer spacing of MXene was increased,and the effects of composition and microstructure on the electrochemical properties of MXene electrode materials were explored.The best prepared electrode material can provide a specific capacitance of 175 F g^-1at a current density of 1 A g^-1.3.MnCo₂O₄/MXene was prepared of by the hydrothermal method.The content of intercalation agent was optimized for Mn Co₂O₄/MXene material to obtain the best doping amount.The best prepared electrode material can provide a specific capacity of 806.7 F g^-1at a current density of 1 A g^-1.Mn Co₂O₄/MXene was assembled into a supercapacitor,and the device could deliver an energy density of26.8 Wh kg^-1at a power density of 2.88 k W kg^-1,and excellent cycling stability.