Template-Free Electrochemical Preparation of Hexagonal CuSn Prism-Structural Electrode for Lithium-Ion Batteries

Abstract

A hexagonal prism CuSn alloy was prepared at room temperature from 1-ethyl-3-methylimidazolium dicyanamide ([Emim][DCA]) by the direct template-free electrodeposition method with different concentrations of Cu(I) and Sn(II) at a low current density of 0.04 A dm −2 . Moreover, the electrodeposition time was also investigated, and the results indicated that the composition of the CuSn alloy became complex and the structure turned unstable with expanding time. The cycling performance of the hexagonal prism-structural CuSn electrode was investigated, with the first discharge capacity of 345 mAh g −1 and a discharge capacity of about 210 mAh g −1 after 10 cycles.

In Operando XANES Imaging of High Capacity Intermetallic Anodes for Lithium Ion Batteries

“…During lithiation and delithiation Cu 6 Sn 5 presents distinct phases, depending upon the voltage. 21 For lithiation two distinct reduction potential plateaus vs Li/Li + define the main points of interest because during these transitions the chemical and morphological changes in the microstructure are more distinguishable. The first reduction in the reaction is shown near the voltage window of 0.4 V vs Li/Li + , and it manifests as a partial lithiation of the material as shown in Eq.…”

“…Delithiation to 1.5 V followed by a constant voltage hold reveals regions of unreacted Cu 6 Sn 5 and the possible reformation of Cu 6 Sn 5 , which has been noted in the literature. 17,21,22 However, there were difficulties in separating the expelled Cu from Cu 6 Sn 5 at 1.5 V, and these two phases could not be clearly distinguished with appropriate tolerance after reaching full delithiation. This error was not observed in the other chemical mapping results and is expected to result from the similarity of the Cu and Cu 6 Sn 5 spectra combined with the 2D nature of the images.…”

“…15,16 Investigations of Cu 6 Sn 5 include first principle calculations and phase transition analysis on the electrode 13 and an array of fabrication methodologies. [17][18][19][20][21] The application of complex 3D microstructures 19,20 and distinct particle geometries 21,22 in these alloy electrodes are common.…”