ORIGINAL STRUCTURAL BEHAVIOUR INDUCED BY ELECTROCHEMICAL REDOX REACTIONS IN Li9TiP4 ANODE

摘要

A combined experimental and computational study of Li9TiP4 electrochemical reactivity towards lithium is presented. This temary phase belongs to the series of transition metal pnictides LixMPn4 (M transition metal Pn pnictogen), recently proposed as promising negative electrode materials for Li-Ion batteries. Prepared through ball milling synthesis, Li9TiP4 shows a specific capacity of 830 mAh/g which is hold on up to 20 cycles at low scan rates. The reversible structural phase transition evidenced by in situ XRD is shown to originate from a "breathing" of the tetrahedral (TIP4) electronic entities which initial structure is built on. This unusual crystalline solid state phase transition is accompanied with small electrode volume change.