New Electrode of La0.75Sr0.25Mn0.5Cr0.5-XCuxO3-δ (x=0, 0.05, 0.10, 0.20) for Symmetric Solid Oxide Fuel Cell

Abstract:

New perovskite oxides La_0.75Sr_0.25Mn_0.5Cr_0.5-xCu_xO_3-δ (LSMCr_0.5-xCu_x, x=0, 0.05, 0.10, 0.20) have been developed as both cathode and anode for symmetric single solid oxide fuel cells (SOFCs). The as-prepared LSMCr_0.5-xCu_x powders are rhombohedral perovskite phase, and their properties are remarkably affected by Cu content (x). For example, the particle sizes and electrical conductivities of LSMCr_0.5-xCu_x increase with x both in air and in 5% H₂-Ar atmosphere. Their p-type conductivity shows lower values under 5% H₂-Ar reducing atmosphere than in air due to the decrease of the ratio of Mn⁴⁺/Mn³⁺ cation pairs through the reduction of Mn⁴⁺. Among of the oxides, LSMCr_0.45Cu_0.05 shows the best anodic and cathodic performance in symmetrical half cells. The maximum power density of a LSMCr_0.45Cu_0.05 / ScSZ / LSMCr_0.45Cu_0.05 symmetric single SOFC reaches as high as 451.2 mW·cm^-2 in wet H₂ as fuel at 900 ^oC.

Keywords: solid oxide fuel cell; symmetric cell; LSCM; Cu substitution

Acknowledgements:

This research was financially supported by the Natural Science Foundation of China (21173147), 973 Program of China (2014CB239700). Thanks were also given to the support of National Key Laboratory of Metallic Matrix Composite Material.

*Corresponding author. Tel.: +86 21 34206255; Fax: +86 21 54741297.

E-mail address: yimei@sjtu.edu.cn (Y.-M. Yin).