Investigation of the Structural and Catalytic Requirements for High-Performance SOFC Anodes Formed by Infiltration of LSCM
Investigation of the Structural and Catalytic Requirements for High-Performance SOFC Anodes Formed by Infiltration of LSCM
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DOI：
10.1149/1.3065971
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发表时间：
2009-01-01
影响因子：
--
通讯作者：
Gorte, R. J.
中科院分区：
文献类型：
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作者：
Kim, G.;Lee, S.;Gorte, R. J.
研究了通过将 45 wt% La(0.8)Sr(0.2)Cr(0.5)Mn(0.5)O(3) (LSCM) 渗透到 65% 多孔氧化钇稳定氧化锆 (YSZ) 支架中形成的复合材料，以了解该材料能够在固体氧化物燃料电池 (SOFC) 中提供优异阳极性能的原因。扫描电子显微镜显示，LSCM 在 1473 K 煅烧后在 YSZ 上形成薄膜，但在 1073 K 还原后该薄膜发生破裂，暴露出长的三相边界。库仑滴定表明 LSCM 和 La(0.8)Sr(0.2)MnO(3) 的还原发生在类似的 P(O(2)) 范围内，并且还原可能是薄膜破裂的原因。为了在 973 K 的加湿 H(2) 中实现低阳极阻抗，有必要添加催化剂。添加 0.5-1 wt% Pd、Rh 或 Ni 足以将具有 60 μm 厚 YSZ 电解质的 SOFC 在 973 K 的加湿 H(2) 中的最大功率密度提高到 >500 mW/cm(2)。添加 1 wt% Fe 或 5 wt% 二氧化铈也提高了功率密度，但程度较小。最后，使用 Pt 浆料作为集流体提高了性能，其程度与有意添加催化剂相似，这表明在电极测试中使用惰性材料的重要性。 (C) 2009 年电化学协会。 [DOI：10.1149/1.3065971] 保留所有权利。
Composites formed by infiltration of 45 wt % La(0.8)Sr(0.2)Cr(0.5)Mn(0.5)O(3) (LSCM) into a 65% porous yttria-stabilized zirconia (YSZ) scaffold were investigated in order to understand the reasons this material is able to provide excellent anode performance in solid oxide fuel cells (SOFCs). Scanning electron microscopy showed that the LSCM forms a film over the YSZ after calcination at 1473 K but that this film undergoes cracking to expose a long three-phase boundary after reduction at 1073 K. Coulometric titration demonstrated that the reduction of LSCM and La(0.8)Sr(0.2)MnO(3) occurred over a similar range of P(O(2)) and that reduction is the likely cause for film cracking. To achieve low anode impedances in humidified H(2) at 973 K, it was necessary to add a catalyst. The addition of 0.5-1 wt % Pd, Rh, or Ni was sufficient to increase the maximum power density of SOFCs with 60 mu m thick YSZ electrolytes to >500 mW/cm(2) in humidified H(2) at 973 K. The addition of either 1 wt % Fe or 5 wt % ceria also improved power densities but to a lesser extent. Finally, the use of Pt paste as the current collector increased performance to a similar extent as intentionally adding catalyst, showing the importance of using inert materials in electrode testing. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3065971] All rights reserved.