On the stability of lithium during ageing of Li/PEO8LiClO4/Li cells

Symmetrical cells consisting of a thin film of PEO8LiClO4 solid-polymer electrolyte sandwiched between two lithium electrodes have been subjected to galvanostatic polarization and concomitant voltage changes measured at several intervals of ageing at ambient temperature. The interfacial resistance is found to increase gradually over about 150 days of ageing. The exponential increase of cell voltage is interpreted in the light of the diffusion-limited lithium-ion transport across the passive surface film on lithium.