Cathode materials for intermediate temperature solid oxide fuel cells

Abstract

The superfine crystallites of Nd1.8Ce0.2CuO 4+δ are obtained when prepared by mechanochemical reaction using different process control agents. The crystallite size, Cs = 34 nm is the smallest for Nd1.8Ce0.2CuO4+δ prepared using salicylic acid process control agent (NCCO(Sa)) as compared to others. The dc conductivity (1.64 S cm-1) is the highest for NCCO(Sa) amongst all, which is attributed to the smallest crystallite size and high sintered density. The agglomeration of superfine grains leads to optimal distribution of nano-pores results in low area specific resistance (1.1 ohm cm2) for the NCCO(Sa). The electrochemical performance suggests adsorption of oxygen by cathode as rate-limiting step. The proposed mechanochemical reaction is useful as a technique for the synthesis of materials with submicron-sized crystallites.