Study On The Battery Technology With Silicon Oxide/Graphite As Anode Material

In recent years,a kind of industrialized silicon oxide has been widely used in production.It has a higher specific capacity than graphite materials,a smaller volume expansion(150%)than silicon,a more stable cycle,and a micron particle size.The composite of silicon and graphite will not cause damage to the graphite structure and can alleviate the above-mentioned series of problems.The most important thing is that the material is simple to prepare and can be mass produced.This thesis is based on the SiO@C/G anode material to study the cell process.The purpose is to match a suitable process system for this composite material to give full play to the best performance of the material.The main research contents are as follows:(1)The effects of different electrolyte systems on the performance of soft-pack batteries with SiO@C/G as the negative electrode and NCM523 as the positive electrode were studied.It is found that the full battery made with the electrolyte system model TC-ESC-6 produced by Tianjin Tianci Electrolyte Company has the best performance.The first coulombic efficiency is as high as 82.18%,and it has the highest capacity retention rate of 84.50%after 250 cycles.(2)The influence of various negative electrode material binders on the electrochemical performance of batteries with SiO@C/G as the negative electrode was compared.it was found that the most matching adhesive system was an acrylic modified adhesive,and the most excellent in all aspects was the TS30 adhesive produced by Taiwan Shuohe Company.The first coulombic efficiency was as high as 83.18%.At a current density of 1350 mA/g,the discharge capacity retention rate was as high as 85.01%after 400 cycles.(3)The effects of carbon black conductive agents,graphite conductive agents,and new carbon nanotube conductive agents on the electrochemical performance of batteries with SiO@C/G as the negative electrode were compared,and The study found that single-walled carbon nanotubes+conductive carbon black(SWCNT+SP)as a conductive system have excellent cycle rate performance.The first coulombic efficiency of the battery is 82.07%,and the discharge capacity retention rate is as high as 86.87%after 300 cycles at a current density of 1350 mA/g.This fully shows that if one-dimensional carbon nanotubes and zero-dimensional conductive carbon black are used in combination,there is a good synergistic effect between the long-range conductive network constructed by the former and the short-range conductive network constructed by the latter on the surface of the active material.