Solid-state structures with volatile sintering aids, and methods for fabrication and use thereof

A battery comprising:

• an anode;
• a cathode;
• and
• a solid-state electrolyte separating the anode from the cathode, the solid-state electrolyte comprising a solid-state ion-conducting structure,
• wherein the solid-state ion-conducting structure comprises:
• a plurality of grains formed of a first material composition;
• and
• a second material composition different from the first material composition,
• the second material composition (i) wets boundaries of the plurality of grains, (ii) fills voids between adjacent grains, or (iii) both (i) and (ii),
• each of the first and second material compositions has an ionic conductivity greater than or equal to approximately 1×10−4 S/cm,
• a melting point of the first material composition greater than or equal to a first temperature, and
• a melting point of the second material composition being less than the first temperature.

A method comprising:

• providing a first powder comprising a first material composition or one or more first precursors of the first material composition, a melting point of the first material composition being greater than or equal to a first temperature;
• providing a second powder comprising a second material composition or one or more second precursors of the second material composition, the second material composition being different from the first material composition, a melting point of the second material composition being less than the first temperature;
• forming a composite pellet by at least mixing the first and second powders together;
• and
• subjecting the composite pellet to a high-temperature heating pulse so as to convert the composite pellet into a solid-state ion-conducting structure, the high-temperature heating pulse comprising exposure to a first sintering temperature of at least 600 K for a duration less than or equal to 60 seconds,
• wherein, within the solid-state ion-conducting structure, the second material composition (i) wets boundaries of a plurality of grains formed by the first material composition, (ii) fills voids between adjacent grains formed by the first material composition, or (iii) both (i) and (ii), and
• each of the first and second material compositions has an ionic conductivity greater than or equal to approximately 1×10−4 S/cm.