First-principles calculations and experimental studies of Sn-Zn alloys as negative electrode materials for lithium-ion batteries

Abstract

The physical characters and electrochemical properties of various phases in a Sn-Zn electrode, such as formation energy, plateau potential, specific capacity, as well as volume expansion, were calculated by the first-principles plane-wave pseudo-potential method based on the density functional theory. Sn-Zn films were also deposited on copper foils by an electroless plating technique. The actual composition and chemical characters were explored by scanning electron microscopy (SEM), X-ray diffraction (XRD), plasma atomic emission spectrometry (ICP), and constant current charge/discharge measurements (CC). The results show that separation phases with tin and zinc including a small quantity of Cu 6 Sn 5 phase were obtained, the initial lithium insertion capacity of the Sn-Zn film was 661 mAh/g, and obvious potential plateaus of about 0.4 V and 0.7 V were displayed, which is in accordance with the results of theoretical calculations. The capacity of the Sn-Zn film decreased seriously with the increase of cycle number.

Alloy Negative Electrodes for Li-Ion Batteries

“…Sn and Zn are immiscible and do not form ternary compounds with lithium. Accordingly, the electrochemistry of Sn–Zn alloys appears to be that of a simple mixture of Sn and Zn. − However, some improvement in cycling has been shown in these studies over that of pure Sn, which is thought to be due to an improved electrode microstructure.…”

Sn‐based Intermetallic Compounds for Li‐ion Batteries: Structures, Lithiation Mechanism, and Electrochemical Performances

“…Except the lithium‐inactive inert matrix, the lithium‐active matrix can also tune the electrochemical performance of Sn anode. As cases, the Sb, Ge, Zn,, and Mg etc. have been explored as matrixes into Sn alloy anode system for lithium storage.…”