Molecular Dynamics Simulation of Amorphous Silicon Anode in Li-Ion Batteries
Journal
Energy Storage and Conversion Materials: Properties, Methods, and Applications
ISBN
9781000868722
Date Issued
2023-01-01
Author(s)
Pan, Li Yi
Abstract
Silicon (Si) anodes have attracted more interest nowadays due to their about 10-fold specific capacity than the commonly used graphite anode. Silicon anode stores lithium by forming lithium-silicon alloys, called the lithiation of the silicon anode. This chapter focuses on the lithiation behavior of amorphous silicon. The effect of the defect concentration in the amorphous silicon is presented by the Li-Si alloy concentration in weakly/highly defected amorphous silicon. Crystalline silicon is found to have a much slower Si-Si bond-breaking reaction rate than amorphous silicon. The lower lithium concentrated Li-Si alloy for amorphous silicon will still accommodate more lithium after the silicon core is fully consumed, which causes the second-stage lithiation in amorphous silicon. Hoop stress on Li-Si alloy layer is a major reason for the cracking of silicon nanowires, while stress concentration makes the status worse. Many theoretical analyses state that the hoop stress does not increase during the 2-phase lithiation process.
SDGs
Type
book part