(Invited) Design of Porous Si/C-Graphite Electrodes with Long Cycle Stability and Controlled Swelling

Tuesday, 3 October 2017: 15:40
National Harbor 7 (Gaylord National Resort and Convention Center)
X. Li, P. Yan (Pacific Northwest National Laboratory), X. Xiao (General Motors, R&D Center), J. H. Woo Sr. (Genera Motors), C. Wang, J. Liu, and J. G. Zhang (Pacific Northwest National Laboratory)
Silicon (Si) is one of the most promising candidates to replace graphite anode in the next generation of Li ion batteries. Although various approaches have been adopted to improve the performance of Si-based anodes during the last decade, a main challenge on the practical application of Si-based anodes, i.e., the thickness swelling of Si based anode has been much less investigated. Here, we use the porous Si/C-graphite electrode as an example to elucidate the design principle for stable Si anodes of controlled thickness swelling. Excellent agreement between the theoretical design and experimental data was demonstrated. The practical electrode (~3 mAh/cm2 loading) with ~650 mAh/g specific capacity has ~82% capacity retention over 450 cycles. The initial electrode swelling upon full lithiation is <20%. The calendered electrodes demonstrated ~56% end-of-life swelling and ~90% capacity retention after 200 cycles. The full-cell of Li(Ni1/3Mn1/3Co1/3)O2 and the pre-lithiated anode demonstrates >84% capacity retention over 300 cycles.