An in-situ sintered model of molten carbonate fuel cells (MCFCs) with environment-friendly aqueous matrices was proposed in order to optimize the performance of MCFC unit cell. The optimum assembly pressure range was settled based on the sintered model. Moreover, an environment-friendly aqueous alpha-LiAlO2 matrix was fabricated by a tape-casting process using distilled water as solvent and was applied into MCFC successfully. The obtained single drying green sheet had a thickness of 200-300 mu m, no defects, and good workability. The microstructure of the alpha-LiAlO2 required in an MCFC was obtained using this method. In this work, the MCFC using the matrices was assembled and tested. The output power density could reach 149.2 mW cm(-2) at the current density of 200 mA cm(-2) when the assemble pressure was 7.01 MPa. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.