The Effect of Plasma Spraying Power on La_0.58Sr_0.4Co_0.2Fe_0.8O_3–δ–La_0.8Sr_0.2Ga_0.8Mg_0.2O_3–δ Composite Cathode Interlayer Microstructure and Cell Performance

Abstract

The metal‐supported intermediate temperature solid oxide fuel cells with a porous nickel substrate, a nano‐structured LDC (Ce0.55La0.45O2–δ)–Ni composite anode, an LDC diffusion barrier layer, an LSGM (La0.8Sr0.2Ga0.8Mg0.2O3–δ) electrolyte, an LSCF (La0.58Sr0.4Co0.2Fe0.8O3–δ)–LSGM composite cathode interlayer and an LSCF cathode current collector are fabricated by atmospheric plasma spraying. Four different plasma spraying powers of 26, 28, 30, and 34 kW are used to fabricate the LSCF–LSGM composite cathode interlayers. Each cell with a prepared LSCF–LSGM composite cathode interlayer has been post‐heat treated at 960 °C for 2 h in air with an applied pressure of 450 g cm–2. The current‐voltage‐power and AC impedance measurements indicate that the LSCF–LSGM composite cathode interlayer formed at 28 kW plasma spraying power has the best power performance and the smallest polarization resistance at temperatures from 600 to 800 °C. The microstructure of the LSCF–LSGM composite cathode interlayer shows to be less dense and composed of smaller dense regions as the plasma spraying power decreases to 28 kW. The durability test of the cell with an optimized LSCF–LSGM composite cathode interlayer gives a degradation rate of 1.1% kh–1 at the 0.3 A cm–2 constant current density and 750 °C test temperature.

Fabrication and performance of atmospheric plasma sprayed solid oxide fuel cells with liquid antimony anodes

“…Carbon black is a popular pore former in this context because of its high melting point and decent oxidizability. Tsai et al (2014) ) cathodes using the APS method with 25 wt% carbon black as a pore former; the polarization resistance was 0.37 X cm 2 at 750°C. However, for cathode-down plasma-sprayed SOFCs, the ratio of pore former in cathode powder still needs to be optimized.…”