Electrochemical Characterization of Cellular Si and Si/C Anodes for Lithium Ion Battery

The structural optimization of Si-based anodes for lithium ion battery is always a promising way to put them into commercial application. In this article, cellular silicon-based anodes were prepared by casting milled Si and Si-C powders into the "valley-ridge" copper architecture. Their electrochemical properties and failure mechanism were studied by means of charge-discharge (C-D) test, differential capacity plots and electrochemical impedance spectroscopy (EIS). In comparison with common anode fabricated with "slurry-coating" technology on flat copper foil, the cellular copper framework has shown a great structural advantage in restricting severe volume changes of silicon particles. This "stress-restriction" environment can effectively suppress stain-induced loosening happened inside electrodes, and consequently improve cycle-life and coulombic efficiency of Si-based anodes.