Lithium ion battery has become widely used for electronic devices due to its high energy density since it was first commercialized in 1991 by Sony. Due to its great performance, lithium ion batteries are becoming an essential piece to enable the electrification of transportation. For decades, Argonne National Laboratory has been working on this advanced technology in a spectrum from very fundamental to much applied aspect with many achievements.
In this talk, I will discuss the most recent studies on silicon material used as anode for lithium ion batteries. Silicon is very reactive and there is always a native oxide layer on the surface to prevent further reaction. The actual thickness of the oxide layer varies a lot due to the manufacturing processes. As the size of the silicon particle becomes smaller, this oxide layer will play a more important role as it takes up a larger volume and weight percentage. Previous study suggests that the presence of oxide layer harms the initial performance of the silicon anodes in a non-aqueous system. However, the effect of the oxide layer on the long cycling performance of the electrodes has not been well studied. Here we investigated the effect of oxide layer on the electrochemical performance of silicon anodes by growing the oxide layer of Si nanoparticles in a controlled manner. The stability of the silicon nanoparticles with different oxide layer thickness during electrode fabrication process was compared. Electrochemical performance of the silicon electrodes of different thicknesses was also analyzed and compared.
We gratefully acknowledge the support from the U.S. Department of Energy’s (DOE) office of Energy Efficiency & Renewable Energy (EERE) Vehicle Technologies Office. This work is performed at Argonne National Laboratory, a U.S. Department of Energy Office of Science Laboratory operated under Contract No. DE-AC02-06CH11357.