Braze compositions, and related devices

An electrochemical cell, comprising:

• a tubular separator disposed in a cell case defining a portion of a cathodic chamber and an anodic chamber, wherein the cathodic chamber comprises an alkali metal halide, and forms an ion that is capable of conducting through the separator;
• an electrically insulating ceramic collar disposed on a top end of the separator;
• and
• a metal ring disposed on the electrically insulating ceramic collar,
• wherein the electrically insulating ceramic collar is joined to the metal ring by a braze alloy composition comprising from about 70 weight percent to about 90 weight percent copper, from about 3 weight percent to about 20 weight percent nickel, and from about 0.5 weight percent to about 5 weight percent of the active metal element, based on the total weight of the braze alloy composition, and wherein the active metal element comprises titanium, zirconium, hafnium, vanadium, or combinations thereof, and wherein the braze alloy composition is in direct contact with both the electrically insulating ceramic collar and the metal ring.