Improving the Electrochemical Performance of Sio Anode Material by Dual-Doping with Lithium and Titanium

Abstract

Silicon monoxide (SiO) has been considered as a potential candidate of high capacity anode material for lithium-ion batteries; however, its low initial Coulombic efficiency (ICE) is a critical problem to overcome. Although a solid-state prelithiation method for SiO using LiH was reported to enhance ICE up to 90.5 %, there are still cycle performance issues that need to be resolved before commercial application. In this presentation, we propose SiO anode material dual-doped with lithium and titanium using metal hydrides to enhance both ICE and cycle performance. This Li-Ti dual-doped SiO material shows improved cycle performance than prelithiated SiO with LiH for up to 500 cycles without sacrificing ICE, because the TiSi2 mechanical buffer phases formed by the reaction with TiH2 accommodate the volume expansion during cycling. Li-Ti dual-doped SiO material also exhibits improved thermal stability at elevated temperatures and rate capability compared to prelithiated SiO with LiH. More detailed material and electrochemical properties of Li-Ti dual-doped SiO will be discussed further in the presentation.