Strategy to Improve Electrochemical Performance and Durability of Positrodes for Protonic Ceramic Cells by Surface Decoration via Infiltration

Abstract

Due to the large polarization resistance (Rp) of positrodes (namely, air/steam electrodes), it is vital to develop high-performance and cost-effective positrodes to improve the performance of protonic ceramic cells (PCCs). In this work, we report a La1.2Sr0.8NiO4+delta (LS8N) positrode decorated with (La,Sr)CoO3-delta (LSC) nanoparticles by infiltrating Co(NO3)(2) solution. Rp of a bare electrode was 4.22 Ocm2 at 600 degrees C, and reduced by almost ten times to 0.49 Omega cm(2) by infiltrating with a 0.2 molL(-1) Co(NO3)(2) solution. Furthermore, although Rp of the bare electrode increased after a durability test by exposing to Ar-20% O2-3% H2O at 600 degrees C for 100 h, Rp of the infiltrated electrode further decreased after the durability test. For example, Rp of the electrode infiltrated with 0.2 molL(-1) Co(NO3) (2) solution reduced to 0.37 Omega cm(2), which is attributed to the enhancement of the LSC/LS8N interface. The good electrochemical performance and durability of the positrodes with LSC/LS8N heterogeneous interface, which can be optimized by controlling the parameters for the infiltration process, suggest a potential strategy for designing excellent positrodes for PCCs.