In recent years, copper-tin has risen as one of the most promising anode materials. It possesses a higher energy density than the conventional graphitic anode electrodes. And, the binary copper-tin alloy seems to mitigate the drastic volume changes, exhibited by other high capacity alloy electrodes (e.g., silicon, tin), during cycling. In order to take the next step, and implement this material in commercial applications (e.g., transport and portable electronics), it’s necessary to have a comprehensive understanding of its electrochemical performance.

In a conventional lithium-ion cell, the electrode consists of a porous intricate composite of three main components: active material, conductive additive and a polymeric binder. Electrochemical performance of these electrodes depends upon not only on the components but also on the electrode microstructure defined by the particle size, electrode thickness, porosity, and composition. The electrode microstructure also evolves according to the cycling condition; hence, the cell performance is affected by these changes.

In the present work, the microstructural-electrochemical interaction on Cu₆Sn₅ composite electrodes is studied. The electrode microstructure is modified by varying the composition and the drying temperature. The effect of the voltage window and its correlation with the copper expulsion phenomena is also analyzed. The former is accomplished through charge/discharge cycling of Cu₆Sn₅ half cells. Morphological changes are studied by removing the electrode from the cell and analyzing it using micrographic (SEM) techniques. Results will show how the mechanical degradation of the electrode impact the long term cycling performance.