Investigation on Lithiation Mechanism of Interphase Ni_3Sn_4 Alloy Used as Anode Material for Lithium-ion Batteries

摘要

Sn-based anode materials have poor cycling performance due to mechanical fatigue caused by volume expansion during lithium insertion and extraction processes. In this work, the mechanism of lithium insertion/extraction in the Ni_3Sn_4 alloy electrode is investigated using the first-principle plane-wave pseudopotential and experimnetal method. The calculated results indicate that the Ni_3Sn_4 has relatively minor expansion ratio and fluctuating electrochemical potential, which is consistent with the experimental result. The Ni_3Sn_4 phase has best cyclic stability during the lithium insertion and extraction processes.