Preparation Of Two-Dimensional Layered Titanium Carbide Based Composites And Their Electrochemical Performance

With the development of social economy,people's demand for energy is rapidly increasing.There are much higher requirements to energy storage equipment because of the application of the green energy system,such as solar and wind energy,and power battery.Due to the shortage of cobalt and lithium elements on earth,the application of traditional lithium-ion batteries in large-scale energy storage is limited.So it is necessary to research on other energy storage systems.Supercapacitors have higher power density and are suitable for high-power energy storage devices;sodium element has higher storage capacity in the earth's crust,so sodium ion batteries similar to lithium ion batteries are expected to be candidates for the next generation of large-scale energy storage devices However,both of them are still in the initial development stage,especially the high-performance electrode materials have yet to be developed.Two-dimensional transition metal carbonitride?MXene?has both metal conductivity and hydrophilicity,and has good prospects for electrochemical energy storage applications.However,research on its electrochemical properties and applications is still in its infancy.In this study,the representative titanium carbide?Ti₃C₂T_x?in MXene material was selected,and the Ti₃C₂T_x-based electrode material was designed and synthesized to discuss its electrochemical performance and try to explore its application potential.The specific research results are as follows:1)Through simple salt-induced polymerization of Ti₃C₂T_x nanosheets combined with vacuum suction filtration process,porous Ti₃C₂T_x film can be quickly obtained by drying,which can be directly used as electrode of water-based supercapacitor.Compared with the conventional suction filter membrane,the mass specific capacity is improved while retaining a relative high density,and it is easy to obtain a high-quality loaded film.By introducing carbon nanotubes as spacers,the capacity and rate capability of the thin-film electrode are significantly improved.2)The tungsten carbide film is deposited on the Ti₃C₂T_x film substrate by magnetron sputtering.The amount of loading can be controlled by controlling the sputtering time.Compared with the base film,the volume specific capacitance of the tungsten carbide composite film is improved.3)Vanadium disulfide?VS₂?nanosheets were synthesized by solvothermal method and heat treatment,and assembled with Ti₃C₂T_x nanosheets by simple liquid-phase mixing to obtain VS₂/Ti₃C₂T_x composite materials,which were used as anode materials for sodium ion batteries.The capacity,cycle performance and rate capability are all good.