Construction of the Ternary Phase Diagram for the Li−Cu−Sb System as the Anode Material for a Lithium Ion Battery

Abstract

Cu 2 Sb is known as a promising anode material for a lithium ion battery due to its good cycle performance and large volumetric capacity. In the present study we aimed to construct the ternary phase diagram for the Li-Cu-Sb system to elucidate the reaction mechanism upon charge-discharge reaction. In this procedure, a new intermediate phase of LiCuSb with a half-Heusler-type structure was found by combining experimental results with theoretical study. The obtained ternary phase diagram accounted for the electrochemical lithiation of Cu 2 Sb by the following three-step reaction: (1) Li incorporation into Cu 2 Sb formed LiCuSb accompanying extrusion of Cu metals, (2) the solid solution process of Li 1+x CuSb (0 e x < ∼0.5) with a Heusler-type structure was followed, and then (3) by further lithiation Li 3 Sb was formed with Cu extrusion as a threephase coexistence reaction. The irreversible capacity at the first cycle was assigned to the structural phase transition from Cu 2 Sb to LiCuSb and Cu. Thus, the present study suggested that the intermetallic compounds with a Heusler-type structure have a promising potential as the anode material for a lithium ion battery with a long life and a large capacity.

Thin films of Cu2Sb and Cu9Sb2 as anode materials in Li-ion batteries

“…As was recently shown [4,5] this problem can, however, be circumvented with materials composed of a mixture of Sb and Sb 2 O 3 nanoparticles obtained by electrodeposition from a solution containing antimony tartrate. As has been shown by several groups [27,[30][31][32][33][34], Cu 2 Sb can likewise be used as anode material in Li-ion batteries. According to Fransson et al.…”

“…The Cu 2 Sb synthesized with the ceramic method which resulted in crystallite sizes larger than 200 nm did, on the other hand, not show corresponding structural reversibility. In addition, several reports have been published [30][31][32][33][34] in which Cu 2 Sb capacities significantly lower than the capacity reported by Fransson et al, have been found, most likely due to poor reversibility in reaction (1). The Cu 2 Sb lithiation and delithiation reaction mechanism has recently been discussed by several groups [30,32,35] and a three-step process has been proposed, in which the reaction (1) has been divided into two separate steps.…”

“…In addition, several reports have been published [30][31][32][33][34] in which Cu 2 Sb capacities significantly lower than the capacity reported by Fransson et al, have been found, most likely due to poor reversibility in reaction (1). The Cu 2 Sb lithiation and delithiation reaction mechanism has recently been discussed by several groups [30,32,35] and a three-step process has been proposed, in which the reaction (1) has been divided into two separate steps. The lithiation mechanisms proposed by Morcrette et al [32] (see reactions (3) and (4)) and Matsuno et al [30] (see reactions (5) and (6)) differ with respect to the extent of the extrusion of Cu in the two steps;…”

Recent progress of computational investigation on anode materials in Li ion batteries

“…First-principles computations were successfully applied to study the thermodynamics of alloys in early time, and by using Nernst equation, voltage profile can also be obtained [39]. Recently, the phase diagram for the Li-Cu-Sb ternary alloys has been constructed by combining XRD measurements and firstprinciples computations [40].…”

Crystalline Sb–Cu alloy films as anode materials for Li-ion rechargeable batteries

“…For Li-ion batteries, Cu 2 Sb was investigated as a source of Sb because its high capacity is comparable to that of graphite [5e7]. Cu 2 Sb undergoes a reversible Li-ion insertion/metal displacement reaction, ultimately leading to the formation of Li 3 Sb and Cu [5,6]. The reaction of a displacement electrode material is facilitated by using nanoparticles of an active material, which enhances the electronic and ionic pathways.…”