A comparative study of polyacrylic acid and poly(vinylidene difluoride) binders for spherical natural graphite/LiFePO4 electrodes and cells

作者:Chong Jin; Xun Shidi*; Zheng Honghe; Song Xiangyun; Liu Gao; Ridgway Paul; Wang Ji Qiang; Battaglia Vincent S
来源:Journal of Power Sources, 2011, 196(18): 7707-7714.
DOI:10.1016/j.jpowsour.2011.04.043

摘要

Anodes containing spherical natural graphite (SNG12) and cathodes containing LiFePO4, both from HydroQuebec, were prepared with aqueous-based polyacrylic acid (PAAH), its neutralized derivatives polyacrylic acid (PAAX) (X = Li, Na, and K), and with conventional poly(vinylidene difluoride) (PVDF) binders. A comparison of electrode performance was made between these three binder systems. The electrodes were optimized by adding elastic styrene butadiene rubber (SBR) and conductive vapor grown carbon fiber (VGCF) in the place of some of the PAAX. Initially. SNG12 and LiFePO4 electrodes were characterized in half cells with Li as the counter electrode. The electrochemistry results show that the use of PAAX binders can significantly improve the initial coulombic efficiency, reversible capacity, and cyclability of SNG12 anodes and LiFePO4 cathodes as compared to that of electrodes based on a PVDF binder. By using an optimized composition for the anode and cathode, SNG12/LiFePO4 full cells with PAALi binder cycled 847 times with 70% capacity retention, which was a significant improvement over the electrodes with PVDF (223 cycles). This study demonstrates the possibility of manufacturing Li-ion batteries that cycle longer and use water in the processing, instead of hazardous organic solvents like NMP, thereby improving performance, reducing cost, and protecting the environment.

  • 出版日期2011-9-15
  • 单位中国电子科技集团公司第十八研究所