The use of samarium-doped ceria(SDC)electrolytes in SOFCs(solid oxide fuel cells)lowers the open circuit voltage(OCV)below the Nernst voltage(Vth).Typically,the open circuit voltage is calculated using Wagners equation.By accounting for the polarization voltage losses,the open circuit voltage can be calculated.However,electrodes degrade over time,and the open circuit voltage cannot be calculated during electrode degradation because the OCV remains unchanged.Many much more refined conventional models are developed to explain the lower OCV using thinner electrolytes.