Abstract : Sol-gel strategies are carefully evaluated and compared to synthesizeă electrolyte materials for Intermediate Temperature SOFCs (Solid Oxideă Fuel Cells). Robust 10-20 mu m thick cubic Yttria-Stabilized Zirconiaă (YSZ), (Y2O3)(0.08)(ZrO2)(0.92), films have been prepared by usingă nanocomposite stable sols composed with ``sol-gel made'' YSZ bindersă and YSZ powder. Two different strategies have been investigated for theă synthesis of 8YSZ binders: a mixed alkoxide-nitrate route in alcoholică media, and an environment-friendly hydrothermal route, in water media.ă Ionic conductivities of similar to 2.5 x 10(-2) S cm(-1) are obtained ată 800 degrees C for powders made by the hydrothermal and the alkoxideă routes. Films synthesized from composite sols that contain commercială YSZ powder and the organic binder or the water-based binder, have beenă deposited on YSZ-NiO cermets and integrated in an entire single fuelă cell. The two optimized routes yield to gastight YSZ electrolytes. Ină particular with the organic-based binder, a maximum power density of 250ă mW cm(-2) at 850 degrees C has been achieved. The proposed route can beă extended to other materials for different applications such asă ferroelectric and dielectric materials.