Solid oxide cells are efficient electrochemical systems for electrical power generation in fuel cell mode (SOFC) and hydrogen production in electrolysis mode (SOEC). To design novel optimized oxygen electrodes with improved mixed ionic-electronic properties, it is of high importance to control the electrode microstructure and composition to obtain large surface areas. Indeed, these properties are essential to increase the number of active sites for the oxygen reduction reaction and to enhance the ionic transfer at the electrode/electrolyte interface. Here, we report recent advances in the design of the state-of-the-art La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) [1], La2-xPrxNiO4+δ (LPNO) [2] with 0 ≤ x ≤ 2, and Pr6O11 [3] oxygen electrodes with grain size and porosity at the nanometre length scales. These active functional layers are fabricated using electrostatic spray deposition (ESD), a unique bottom-up method capable of depositing films with original morphologies by a nano-texturing approach. This talk will show our latest electrochemical performance results of these innovative oxygen electrodes investigating the role of the nanostructure and the electrode/electrolyte interface. The correlation between microstructure, composition, grain size, interfaces, and electrochemical properties is discussed in detail for the different investigated oxygen electrodes.