Monolithic integration of nanoscale solid oxide fuel cell membranes onto polymer scaffolds through stress control

Ultrathin fast-ion conducting oxide membranes are of broad interest to a range of energy conversion technologies. We demonstrate a low-temperature (<30 °C) process for controlling internal stress in an archetypal fast-ion conductor, crystalline Y2O3-doped ZrO2 (YDZ), which allows us to form stable suspended nanomembranes akin to those fabricated at high temperature (>550 °C). Such a low-temperature synthesis method then enables us to monolithically integrate the suspended oxide-ion conducting membranes onto polyimide (Kapton by DuPont), a polymer with vastly different physical properties than that of a ceramic. Integrated functional heterostructure solid oxide fuel cells operable below the glass transition temperature of the polymer are demonstrated. Our results describe a mechanistic low-temperature processing route for forming stable multifunctional membrane structures, applicable to the realization of various energy conversion and sensing devices and structural skins for miniature autonomous systems.