Intermediate-temperature solid oxide fuel cells (IT-SOFCs) are promising SOFC technologies that can solve many problems of high-temperature SOFCs (HT-SOFCs), such as the stringent restriction on material selection, accelerated degradation of electrode activity, limitation in thermal cycling, and requirement for long start-up times. In this study, a comprehensive three-dimensional micro/macroscale model is developed for simulating planar, anode-supported IT-SOFCs fueled with hydrogen. Many constitutive sub-models for electrode microstructure, detailed charge-transfer processes, and heat/mass transport in three-dimensional interconnect plate/gas channel geometries are combined to investigate the performance and operating characteristics of IT-SOFCs with rather standard materials (such as nickel, YSZ, LSM, and stainless steel). The current-voltage performance curves are presented along with the contribution of activation, concentration, ohmic, and contact overpotentials to total potential loss. In addition, the spatial distributions of temperature, current density, and species concentrations are also investigated for co- and counter-flow configurations. The results clearly demonstrate the capabilities of the present three-dimensional micro/macroscale model as an accurate and efficient design tool for optimizing the operating conditions, electrode microstructures, and cell geometries of planar, anode-supported IT-SOFCs. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.