We pioneered the study of the electrode properties of glasses containing 80 and 85 wt % LiF and 20 and 15 wt % Al(PO₃)₃. LiF-80-based glass electrodes functioned as lithium-selective electrodes in 1-0.0001 M LiCl solutions. Contrary to aliminosilicate glasses, these glasses responded to the Li⁺ ion better than to the Na⁺ ion and were nonselective to the H⁺ ion. This made them promising for the development of sensors for Li⁺ ions in different solutions. Forward and reverse transitions of these glasses from the hydrogen to the lithium function and from the lithium to the sodium function are described by the equation of the simple Nikol'skii theory.