Microstructure Modification In The Electrodes To Enhance Performance Of The Anode-Supported Solid Oxide Fuel Cell

The electrochemical reaction efficiency for an SOFC is determined mainly at the interfaces between electrodes and electrolyte. The cell performance is influenced by a variety of parameters, such as the particle size, porosity, and microstructure. Microstructural tuning in the electrodes hence provides the performance elevation by increase the effective interfacial reaction sites. In this study, we use traditional materials to form the cells constructed with NiO-YSZ (Yttria stabilized zirconia) as anode supported substrate, YSZ as electrolyte, and YSZ-La0.8Sr0.2Mn0.3 (LSM) vertical bar LSM as functional and cathode layers. In the anode, two different cermet structures with powder refinement approach have been adopted to increase the oxygen exchange rate. On the other hand, introducing LSM-YSZ composite as functional layer is essential for the limited ion conductivity of LSM, which will be beneficial for power output. The cell performance elevation and microstructure analysis allows us to verify functions of sub-micron cermet at anode during the cell operation. The composition effect in cathode may also favor the enhancement. Three typical cells were prepared, and the maximum power density is 280 mWcm(-2) for cell with original materials used. The power density increases to 395 mWcm(-2) for the cell with cermet particle refinement. It further improves to 520 mWcm(-2) for cell with cathode functional layer modification. The small grain size of several tens nano-meter structure in the interfaces exists in a local region near interfaces. It is evidenced that the nano-sized electrode materials which may be attributed to the high current loading can increase the triple phase boundary (TPB) density.