High power density performance at intermediate (600 degrees C-450 degrees C) temperatures (IT) must be considered in the development of solid oxide fuel cell (SOFC). A niobium and tantalum co-doped perovskite material SCNT (SrCo0.8Nb0.1Ta0.1O3-delta) can be used as a cathode for IT-SOFC due to its (H+/O2-/e(-)) triple conduction and promising catalysis activity. In this work, the SCNT was composited with ionic conductor SCDC(Ce0.8Sm0.05Ca0.15O2-delta) and processed as electrolyte membrane into semiconductor-ionic membrane fuel cell (SIMFC), which delivered an appreciable performance at IT, i.e., a peak power output of 1016 mW/cm(2) at 550 degrees C and 401 mW/cm(2) at 450 degrees C, respectively. The high performance mainly originated from the (H+/O2-) dual-ion conduction of SCNT as well as the high oxygen ion conductivity of SCDC, the SCNT-SCDC electrolyte layer adjacent to cathode have promoted the oxygen reduction reaction (ORR) with some extent because of the excellent catalysis activity of SCNT. Moreover, the on-line generated carbonate suppressed the electronic conductivity and resulted in the attractive density of SCNT-SCDC electrolyte to further contribute to the desired cell performance. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.