Among the Ruddlesden-Popper series, La(n+1)NinO(3n+1) (n = 1, 2, and 3) has attracted tremendous attention as an intermediate temperature solid oxide fuel cell (IT-SOFC) cathode because of its favorable properties for realizing high performance. Inter alia, La4Ni3O10-delta (n = 3) has in particular gained recognition as a promising cathode material owing to its high electrical conductivity and cell performance in IT-SOFC applications. The fabrication of nano-sized La4Ni3O10-delta composites requires a low sintering temperature process because high sintering temperature gives rise to solid state reactions between the constituents, which leads to the formation of an undesired electrical insulator and the formation of a low surface area thin-film on the surface. The infiltration method is therefore chosen to fabricate nano-sized La4Ni3O10-delta composites because it can provide reduced particle size of La4Ni3O10-d by separating the sintering process of the cathode from the high temperature sintering process of the electrolyte. In this work, we investigated the electrochemical properties of La4Ni3O10-delta composites prepared by an infiltration method in terms of application as an IT-SOFC cathode material as well as the effect of strontium doping at La sites. (C) The Author(s) 2014. Published by ECS. All rights reserved.