Intermediate temperature solid oxide fuel cells are efficient energy-conversion systems for electrical power generation. In order to design novel optimized cathodes with improved mixed ionic-electronic properties, it is of high importance to control (i) the electrode microstructure and composition to obtain large surface areas, increasing the number of active sites for the oxygen reduction reaction, (ii) the electrode/electrolyte interface to enhance the charge transfer. Recent developments are discussed in the design of Pr doped lanthanum nickelates, La2-xPrxNiO4+δ (LPNO) with 0 ≤ x ≤ 2 using electrostatic spray deposition, a unique method capable of creating special microstructures. This talk will end with our latest results incorporating a composite sub-layer to the double layer LPNO electrode, to investigate the role of the electrode/electrolyte interface. The correlation between microstructure, composition, interfaces and electrochemical properties is discussed in detail.