Wu Lei, Zheng Haoyu, Yang Xin, Qi Huiying, Tu Baofeng, Zang Chunyan, Jia Lichao, Qiu Peng
Shandong University of Science and Technology, Qingdao 266590, China.
Institute of Building Energetics, Thermotechnology and Energy Storage (IGTE), University of Stuttgart, Pfaffenwaldring 31, Stuttgart 70569, Germany.
ACS Appl Mater Interfaces. 2023 Oct 31. doi: 10.1021/acsami.3c13513.
Interfacial delamination between the oxygen-electrode and electrolyte is a significant factor impacting the reliability of solid oxide electrolysis cells (SOECs) when operating at high voltages. The most effective method to mitigate this delamination is to decrease the interfacial oxygen partial pressure, which can be accomplished by amplifying the oxygen exsolution rate and the O transport rate of the oxygen-electrode. In this study, a SrCoTaO (SCT) film with an outstanding oxygen surface exchange coefficient and an outstanding O conductivity was introduced onto the LaSrCoFeO (LSCF) surface by infiltration. This composite oxygen-electrode exhibited a notably high electrochemical catalytic activity primarily due to the significantly improved O transport and oxygen surface exchange rate. Single cells with a 15-LSCF oxygen-electrode achieved a peak power density of 1.33 W cm at 700 °C and a current density of 1.25 A cm at 1.3 V (60% HO-H) at 750 °C. Additionally, an electrolysis cell with a 15 wt % SCT-infiltrated LSCF oxygen-electrode demonstrated stable operation even at high current densities for over 330 h with no noticeable delamination. The remarkable durability of the 15-LSCF oxygen-electrode can be attributed to the boosted oxygen exsolution reaction (OER) activity and the suppression of Sr segregation due to SCT infiltration. The impressive OER activity and resistance to interfacial delamination make the 15-LSCF a promising candidate for a composite oxygen-electrode in SOECs.
在高电压下运行时，氧电极与电解质之间的界面分层是影响固体氧化物电解池（SOEC）可靠性的一个重要因素。减轻这种分层的最有效方法是降低界面氧分压，这可以通过提高氧电极的氧析出速率和氧传输速率来实现。在本研究中，通过浸渍法在LaSrCoFeO（LSCF）表面引入了具有出色氧表面交换系数和出色氧电导率的SrCoTaO（SCT）薄膜。这种复合氧电极表现出显著的高电化学催化活性，主要是由于氧传输和氧表面交换速率得到了显著提高。具有15-LSCF氧电极的单电池在700°C时实现了1.33 W cm的峰值功率密度，在750°C时在1.3 V（60% H₂O-H₂）下实现了1.25 A cm的电流密度。此外，具有15 wt% SCT浸渍的LSCF氧电极的电解池即使在高电流密度下也能稳定运行超过330小时，没有明显的分层现象。15-LSCF氧电极的显著耐久性可归因于增强的氧析出反应（OER）活性以及由于SCT浸渍而对Sr偏析的抑制。令人印象深刻的OER活性和对界面分层的抗性使15-LSCF成为SOEC中复合氧电极的一个有前途的候选材料。
