Enhancing Active Surface Area and Gas Diffusion Properties of Low‐Temperature Solid Oxide Fuel Cell Cathodes by Sputtering with Glancing Angle Deposition

ABSTRACT This paper reports an effective approach we have developed to sputter nanoporous single‐phase La 0 . 6 Sr 0 . 4 Co 0 . 2 Fe 0 . 8 O 3 ‐ δ (LSCF) thin‐film cathodes using glancing angle deposition (GLAD), which leverages the self‐shadowing effect to engineer nanocolumnar architectures with high porosity. By systematically tuning the sputtering pressure and film thickness, we achieved precise control over the cathode morphology, resulting in tunable porosity and triple‐phase boundary (TPB) density. The GLAD‐fabricated LSCF cathode deposited at 0.40 Pa exhibited a nanocolumnar porosity of 21.5%, compared to 7.5% for a conventionally sputtered LSCF film. At a thickness of 240 nm, this cathode achieved a polarization resistance of 6.4 Ω cm 2 at 500 °C, in contrast to 32.9 Ω cm 2 for its conventionally sputtered counterpart. Electrochemical analysis attributed this improvement to enha…