In one general aspect, the techniques disclosed here feature a fluoride ion conductor containing rubidium, magnesium, and fluorine. In an average composition of the fluoride ion conductor, the ratio of the number of moles of the magnesium to the total number of moles of the rubidium and the magnesium is less than 0.4.
Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. The benefits and/or advantages may be individually obtained by the various embodiments and features of the specification and drawings, which need not all be provided in order to obtain one or more of such benefits and/or advantages.
Underlying Knowledge Forming Basis of the Present Disclosure