Preparation And Mechanism Of Structural C/Ga Based Composite Anode Materials

In order to improve the volume expansion and cycle performance of the anode electrode material in the charge and discharge process,this paper uses gallium-based liquid metal with fluidity and self-healing properties and high-capacity,chemically stable metal tin and indium for high-temperature melting and ultrasound.Disperse preparation of gallium-based multi-element liquid alloy nanoparticles,composite with flexible porous carbon nanofiber membranes to prepare structural C/Ga-based composite materials as self-supporting anode materials,analyze the distribution of Ga-based liquid alloys in flexible carbon nanofiber membranes,and test the electrochemical performance of Ga-based liquid alloy in the anode material of lithium ion battery.The main research work is as follows:1.The flexible porous carbon nanofiber membrane is prepared by electrospinning technology,CO₂activation and high temperature carbonization.The carbonized nanofiber membrane has a pore size distribution of 0.6 um-0.8 um,which can be directly used as a self-supporting material to assemble CR2032-Type button battery.2.The flexible porous carbon nanofiber membrane prepared in the previous chapter was used to adsorb in situ GaSnliquid alloy nanoparticles made by high-temperature melting and ultrasonic dispersion to prepare C/GaSncomposites.After 3D microscope,SEM-mapping,TG,XRD characterization and electrochemical performance test,the results show that the GaSnliquid alloy is distributed between the nanofiber layers and fixed at the fiber intersection.At a current of 50 m A/g,the first turn efficiency is 54.29%,which is higher than the first turn efficiency（49.0%）of pure carbon nanofiber membranes.The capacity retention rate for 200 cycles is97.1%,indicating that the C/GaSncomposite anode material stable cycle performance.3.Adopt the same experimental method as the previous chapter to adsorb GaIn liquid alloy to prepare structural C/GaIn composite material.After 3D microscopy,SEM-mapping,TG,XRD and other characterization methods and electrochemical performance tests,the GaIn liquid alloy has obvious spherical particles,and the particles with a particle size of less than 500 nm are mainly distributed in the nanofiber layer,which is.The spherical particles greater than 500 nm are piled up on the surface of nanofibers.At a current of 50 m A/g,the first cycle efficiency is 73.7%,and the capacity retention rate for 200 cycles is 68.1%.4.Using the same experimental method as the previous two chapters,the GaSnIn liquid alloy was adsorbed to prepare C/GaSnIn composite material,which was characterized by 3D microscope,SEM-mapping,TG,XRD and electrochemical performance test.It was found that the surface of the nanofibers had flakes and spherical particles.The flakes were mainly distributed on the surface of the nanofiber bundles.The spherical particles were distributed in the fiber layer and were entangled by the fibers and fixed between the fiber layers.At a current of 50m A/g,the efficiency of the first lap is 74.6%,and the capacity retention rate of the200 cycles is 72.4%.