Investigation on Lithiation Mechanism of Interphase Ni3Sn4 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 Ni3Sn4 alloy electrode is investigated using the first-principle plane-wave pseudopotential and experimnetal method. The calculated results indicate that the Ni3Sn4 has relatively minor expansion ratio and fluctuating electrochemical potential, which is consistent with the experimental result. The Ni3Sn4 phase has best cyclic stability during the lithium insertion and extraction processes.