Set forth herein are processes for making and using electrolytes (also known as catholytes when the electrolytes are mixed with cathode active materials) for a positive electrode of an electrochemical cell. The catholytes include additives that prevent surface fluorination of lithium-stuffed garnet solid-state separators in contact with the positive electrode. Also set forth herein are electrochemical devices which include the catholytes in addition to a lithium-stuffed garnet solid-state electrolyte separator.