Fluoride‐Conducting Solid Electrolytes in Galvanic Cells

Concentrated fluoride‐excess solid solutions based on the alkaline earth fluorides and with CeF 3 and UF 4 as dopants are suitable solid electrolytes for application in thin film galvanic cells. Galvanic cells were fabricated using Pb or Ca as the anode, the concentrated solid solutions as electrolytes, and either BiF 3 or BiO 0.1 F 2.8 as the cathode. Discharge characteristics were studied in air from 300° to 540°K. The cells are rechargeable. The electrical properties of BiF 3 were studied and compared with data reported for BiO 0.1 F 2.8 . Partly discharged cells contain anode passivation layers which consist mainly of Pb 2 OF 2 when Pb is the anode, and of nominally pure CaF 2 in which fluoride interstitials carry the current if Ca is the anode