The results indicate a minimum threshold porosity of the NiO/YSZ substrate, which is 52.5% and 58.5% porosity for 100 and 25V applied potentials, respectively. Cherng et al. [114] showed that Ni/YSZ cermet presintered at 1200C and reduced at 700C behaves like a metal electrode and does not require the use of the additional electrical conducting backing layer