Mn-doped Ruddlesden-Popper oxide La1.5Sr0.5NiO4+δ as a novel air electrode material for solid oxide electrolysis cells
Mn-doped Ruddlesden-Popper oxide La1.5Sr0.5NiO4+δ as a novel air electrode material for solid oxide electrolysis cells
复制标题
DOI：
10.1016/j.ceramint.2020.08.239
复制
发表时间：
2021
影响因子：
5.2
通讯作者：
Yifeng Zheng;Huaguo Jiang;Shun Wang;B. Qian;Qing-shan Li;Lin Ge;Han Chen
中科院分区：
文献类型：
--
作者：
Yifeng Zheng;Huaguo Jiang;Shun Wang;B. Qian;Qing-shan Li;Lin Ge;Han Chen
固体氧化物电解槽(SOEC)是一种很有前途的高效能量转换和储存的电化学装置。本工作采用传统的固相法合成了La1.5Sr0.5Ni1-xMnxO4+δ(LSNMx)(x=0.10，0.10，0.25，0.5，0.75)Ruddlesden-Popper氧化物，并将其作为SOEC潜在的空气电极材料进行了研究。研究了用Mn取代Ni对材料的晶体结构、氧含量、热膨胀行为、电导率和电化学性能的影响。X射线衍射结果表明，LSNMx中Mn的固溶体浓度不能超过0.5。O1S的X射线光电子能谱表明，Mn掺杂增加了氧空位的浓度。LSNMx(x=0，0.1，0.25，0.5)的极化电阻(Rp)随Mn含量的增加而显著减小。在800℃时，LSNM0.5的Rp值最低，为0.488Ω/cm2，比LsN电极的RP值降低了81.1%。在燃料电极支撑的单电池中，以70%CO2+30%CO为原料气体的LSNM0.5空气电极在800℃时的电流密度为500mA/cm−-21.4V，与未掺杂的电极相比，电流密度提高了约85.2%。半电池的稳定性测试表明，LSNM0.5空气电极在500mA/cm−和800℃空气中极化145h后相对稳定，因此，掺锰的LSNM0.5Ruddlesden-Popper材料是一种很有前途的空气电极材料。
Solid oxide electrolysis cell (SOEC) is a promising electrochemical device with high efficiency for energy conversion and storage. In this work, La1.5Sr0.5Ni1-xMnxO4+δ(LSNMx) (x = 0, 0.1, 0.25, 0.5, 0.75) Ruddlesden-Popper oxides are synthesized via the conventional solid-state method and evaluated as potential air electrodes for SOEC. The effects of substituting Mn for Ni on the crystal structure, oxygen content, thermal expansion behavior, electrical conductivity, and electrochemical performance are comprehensively investigated. XRD results show that the solid-solution concentration of Mn in LSNMx cannot exceed 0.5. The X-ray photoelectron spectroscopy of O1s suggest that Mn doping increases the concentration of oxygen vacancy. The polarization resistance (Rp) of LSNMx (x = 0, 0.1, 0.25, 0.5) exhibits a significantly decreasing tendency with increasing Mn content. LSNM0.5 shows the lowest Rp value of 0.488 Ω cm2at 800 °C and is reduced by as much as 81.1% in comparison with that of the LSN electrode. A current density of 500 mA cm−2at 1.4 V is obtained for the LSNM0.5 air electrode with 70% CO2+ 30% CO feed gas on the fuel electrode in a fuel electrode-supported single cell at 800 °C. This current density shows an increase of approximately 85.2% compared with that of the un-doped LSN electrode. The stability test of the half-cell shows that the LSNM0.5 air electrode is relatively stable after anodic polarization at 500 mA cm−2and 800 °C in air for 145 h. Thus, the Mn-doped LSNM0.5 Ruddlesden-Popper material is a promising air electrode for SOEC.