Preparation and characterization of ceramic interconnect La_0.8Ca_0.2Cr_0.9M_0.1O_3−δ (M = Al, Co, Cu, Fe) for IT-SOFCs

详细信息    查看全文

• 作者：Yen-Pei Fu ; ^a ; ^{d887503@alumni.nthu.edu.tw} ; Hsin-Chao Wang^a
• 关键词：SOFC ; Interconnects ; Electrical conductivity ; Mechanical properties ; Weibull plot
• 刊名：International Journal of Hydrogen Energy
• 出版年：2011
• 出版时间：January 2011
• 年：2011
• 卷：36
• 期：1
• 页码：747-754
• 全文大小：744 K

文摘

The lattice parameters, electrical conductivity, activation energy, mechanical properties, and microstructure of (La_0.8Ca_0.2)CrO_3−δ-based specimens were investigated systematically in this paper. The tolerance factors for (La_0.8Ca_0.2)CrO_3−δ-based specimens were all greater than 0.9, indicating the perovskite was not distorted with different cations (Al³⁺, Co³⁺, Cu²⁺, Fe³⁺) substitution for B site of (La_0.8Ca_0.2)CrO_3−δ. (La_0.8Ca_0.2)Cr_0.9Co_0.1O_3−δ specimen revealed the maximum electrical conductivity, σ_850 °C = 59.59 S/cm with minimum activation energy, E_a = 11.2 kJ/mol among (La_0.8Ca_0.2)CrO_3−δ-based specimens. The grain size seemed dependent on doping species and the grain sizes were distributed in the range of 2.4–5.6 μm for (La_0.8Ca_0.2)CrO_3−δ-based specimens. The rate of grain growth was proportional to the boundary mobility M_b, which was related to the diffusion coefficient of doping cation. (La_0.8Ca_0.2)CrO_3−δ-based specimens revealed variety in microhardness, in the range of 4.33–9.85 GPa and the fracture toughness were distributed in the range of 3.52–4.33 MPa m^1/2. Based on the results in terms of grain size and mechanical properties, we concluded that the microhardness and fracture toughness were dependent on the dopant ions. The (La_0.8Ca_0.2)Cr_0.9Co_0.1O_3−δ specimen shows high electrical conductivity and mechanical properties Consequently, it is a promising candidate as an interconnect material for intermediate temperature solid oxide fuel cell (IT-SOFC) applications.