Scalable Synthesis of High Performance Silicon Anode by Impregnation of Pitch in Nanoporous Silicon

Wednesday, 12 October 2022: 10:30
Room 219 (The Hilton Atlanta)
R. Yi, S. Chae, Y. Xu, H. S. Lim (Pacific Northwest National Laboratory), D. Velickovic (PNNL), X. Li, Q. Li, C. Wang, and J. G. Zhang (Pacific Northwest National Laboratory)
Silicon (Si) has been regarded as one of the most promising anode materials for the next generation LIBs with high energy density because it has 10 times higher theoretical specific capacity (4200 mAh/g) than that of graphite. However, severe volume change (~300%) of Si during lithiation and delithiation hinders the practical application of Si anode by 1) particle fracture and pulverization, 2) disintegration of electrode, and 3) continuous electrolyte-decomposition at the newly exposed Si surface. A novel process has been developed for the preparation of porous Si/C composite-based anode which demonstrate highly stable cycling stability. The enabling factor is a wet chemical, low temperature pitch coating process that uses readily available, low-cost, and abundant precursors. The porous Si nanostructure can be preserved by impregnating petroleum pitch before high-temperature treatment. A full cell with 80 wt% pitch-derived carbon/nanoporous Si in the anode has been demonstrated with 80% capacity retention after 450 cycles. Low swelling in both particle and electrode levels has also been observed. It is expected that the unique process developed in this work is also applicable for the development of other alloying-type anodes that require preservation of the desired nanostructures during high temperature treatment.