Properties of a Carbon Negative Electrode in Completely Inorganic Thin Film Li-Ion Batteries with a LiCoO2 Positive Electrode

Abstract

AbstractCompletely inorganic thin film lithium ion battery cells have been prepared by vapor deposition processes (vacuum evaporation and sputtering). The negative and positive electrodes were films of disordered carbon and lithium cobalt oxide, respectively. The results of battery charging/discharging and other measurements (e.g., in-situ lithium chemical diffusion constant measurements for the carbon films) indicate that disordered carbon films have a relatively high reversible charge capacity, (> 160 mC/μmand possibly higher than 360 mC/cm2-μm, or > 296 and possibly 667 mAh/g, respectively, assuming the measured film density of 1.5g/cm3), and a lithium chemical diffusion constant at room temperature ≈10-9 cm2/s. These results suggest that disordered carbon films should be good substitutes for metallic lithium in thin film rechargeable batteries.