High-temperature electrochemical devices operate via an ion gradient that develops across a solid electrolyte. Consequently, hermeticity across this membrane is paramount. Not only must the electrolyte contain no interconnected porosity, but it must be connected to device chassis with a gas-tight seal. Here we report a new method of brazing developed specifically for solid-state electrochemical applications. We demonstrate that the seal is hermetic and resistant to thermal aging, can be thermally cycled under rapid heating rates with no measurable loss in seal strength, and has shown promise in sealing full-size planar solid oxide fuel cell (pSOFC) components. (C) 2005 The Electrochemical Society.