A simple and novel Si surface modification on LiFePO4@C electrodeand its suppression of degradation of lithium ion batteries

作者：Yang, Wenyu; Zhuang, Zhenyuan; Chen, Xiang; Zou, Mingzhong; Zhao, Guiying; Feng, Qian; Li, Jiaxin; Lin, Yingbin^*; Huang, Zhigao

来源：Applied Surface Science, 2015, 359: 875-882.

DOI：10.1016/j.apsusc.2015.10.224

• LiFePO4 cathode
• Nano sized Si surface modification
• Lithium ion batteries
• Ultrasonic spray

A simple and novel surface modification device of the electrodes based on the ultrasonic spray technique was set up, which is considered to have the enormous prospect of industrial application due to its simpleness and high efficiency. Then, the nano-sized Si nanoparticles were deposited uniformly on the LiFePO4@C electrodes. In comparison with pristine LiFePaRC electrode, the surface modification of the nano-sized Si with crystalline Si core and amorphous Si shell on the electrode surface exhibits less coarsening degree, higher rate capability, better cyclicity at high charge/discharge rate, especially at elevated temperature. Moreover, Raman spectra of LiFePO4@C, LiFePO4@C/Si electrodes before cycles and after 100 cycles at 1 C and 60 degrees C were measured. It is found that the FePO4 and alpha-Fe2O3 phases exist in LiFePO4@C after 100 cycles. On the contrary, there hardly exists the FePO4 and alpha-Fe2O3 phases, which means that the nano Si surface modification suppresses the degradation of lithium ion batteries. At last, the schematic and phenomenological resistance models of LiFePO4@C electrode modified by the nano-sized silicon particles have been suggested, which is responsible for the enhancement of the electrochemical performances after nano-sized Si surface modification.

• 出版日期2015-12-30
• 单位福建师范大学