Ionic Conduction of Li 2 O‐2SiO 2 Glass Under DC Potential

A charging current flows under a dc potential applied to electrodes on Li 2 O 2SiO 2 glass, producing effects that cannot be ignored. These effects aid in understanding the behavior of the charging current when charges are transported across the boundaries between the electrodes and the glass and are more important, even at room temperature, for glasses with relatively good conductivities, e.g. Li 2 O‐2SiO 2 glass. The current for lithium ion penetration into the cathode was estimated from the amount of the lithium in the cathode material. The phenomenological comparison of the current determined by subtracting the penetration current from the charging current indicates that this resultant current is not only attributed to accumulation of the lithium ions transported from the bulk of Li 2 O 2SiO 2 glass into the surface layer adjacent the cathode, but also to displacement (toward the anode) of the oxygen ions in the lithium‐depleted region developed near the anode. This conclusion is qualitatively confirmed by the observed depth concentration profiles of oxygen distributed in the surface layers adjacent the electrodes.