Preparation of Si/TiO2 Composite by the Sol-Gel Method Using As the Lithium-Ion Battery Anode

3rd Annual International Workshop on Materials Science and Engineering

Wang, Quanwei^1 ; Ban, Yueqin^3 ; Zhou, Hengwei^1 ; Zhang, Lili^1,2 ; Huang, Yineng^1,2 ; Shao, Weiquan^3 ; Chen, Shaou^1,3

Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matters, College of Physical Science and Technology, Yili Normal University, Yining

835000, China^1

National Lab of Solid State Microstructures, School of Physics, Nanjing University, Nanjing

210093, China^2

College of Physics, Qingdao University, Qingdao

266071, China^3

关键词: Capacity fading;    Charge capacities;    Composite electrode;    Initial Coulombic efficiency;    Lithium insertion;    Lithium-ion battery anodes;    Structural failure;    Volume expansion;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/250/1/012054/pdf
DOI  :  10.1088/1757-899X/250/1/012054

来源: IOP

【 摘 要 】

Si was a promising anode material for next-generation LIBs due to its extremely large capacity of 4200mAh/g (Li4.4Si phase). However, during repeated lithium insertion/extraction processes, the accompanied huge volume change (400%) induced the structural failure of the active material and resulted in rapid capacity fading. To overcome this problem, Si/TiO2composite with different mole ratio were prepared by the sol-gel method. The inclusion of TiO2not only worked as a stable electric conductive pathway but also buffered the volume expansion of the Si during the process of charging and discharging. The Si/TiO2composite with different mole ratio of 1:2, 1:3, 1:4 electrode reaches 480mAh/g, 2590mAh/g and 980mAh/g, and it delivered a charge capacity of 461mAh/g, 2510mAh/g and 891mAh/g at the first cycle, corresponding to an initial coulombic efficiency of 96%, 96% and 91%. In contrast, the cell with the pure Si nanoparticle exhibited an initial discharge/charge capacity of 48 and 33mAh/g, respectively, which was much lower than the Si/TiO2composite electrode.