Passivating Ability of Surface Film Derived from Vinylene Carbonate on Tin Negative Electrode

The passivating ability of surface film derived from vinylene carbonate (VC) is addressed on tin (Sn) negative electrode after a comparative study on the thickness, film growth pattern, chemical composition, and mechanical flexibility of the surface films generated from VC-free and VC-added electrolytes. The surface film derived from the former electrolyte is enriched by inorganic fluorinated and carbonate species, and shows a poor passivating ability to cause a continued electrolyte decomposition, film growth and eventual electrode failure. In contrast, organic carbon-oxygen species are dominant in the film derived from the VC-added electrolyte. Even if this film is thinner than the other, it passivates the Sn electrode surface more effectively. As a result, the film growth and electrode polarization are less significant. The superior passivating ability of organic-rich surface film has been ascribed to a uniform coverage and higher mechanical flexibility.