Lithiation and Delithiation Properties of Si-based Electrodes Pre-coated with a Surface Film Derived from an Ionic-liquid Electrolyte

Ionic-liquid electrolytes can enhance battery performance and safety but are expensive. To reduce the use of ionic-liquid electrolytes, we investigated the charge/discharge properties of Si-based electrodes in an organic-liquid electrolyte, where the electrode surface was pre-coated with a film derived from an ionic-liquid electrolyte. No improvement in the electrode performance was observed compared to that of a nonmodified Si electrode. Once the modified film was broken down, a stable surface film could not be reformed in the organic-liquid electrolyte. To reduce the use of ionic-liquid electrolytes (IL) in batteries, we invesitigated the lithiation/delithiation properties of Si-based electrodes in an organic-liquid electrolyte (Org), where the electrode surface was preliminarily coated with an IL-derived film. The electrode cycle life was not improved compared with that of a nonmodified electrode because the stable surface film should be broken down in the Org.