Lithiation induced corrosive fracture in defective carbon nanotubes

We perform molecular dynamics simulations to elucidate lithiation induced fracture mechanisms of defective single-walled carbon nanotubes (SWCNTs). Our simulations reveal that variations of defect size and lithium concentration set two distinct fracture modes of the SWCNTs upon uniaxial stretch: abrupt and retarded fracture. Abrupt fracture either involves spontaneous lithium weakening of the propagating crack tip or is absent of lithium participation, while retarded fracture features a wait-and-go crack extension process in which the crack tip periodically arrests and waits to be weakened by diffusing lithium before extension resumes. Our study sheds light on the rational design of high-performance CNT-based electrodes. (C) 2013 AIP Publishing LLC.