固体氧化物电解池（SOEC）是一种高效、全固态能量转换装置，能将可持续能源产生的电能转换为化学能储存起来，具有清洁、高效、反应物灵活和无贵金属催化剂等优点，是未来碳中和技术的重要组成部分。研究表明，CO₂还原过程是SOEC电解CO₂还原的最大限速步，因此开发高活性与高稳定性的阴极材料是SOEC的主要研究方向。传统的Ni基陶瓷（如Ni-YSZ）因高催化活性和导电性而常用于阴极，但在高温CO₂电解中易发生金属Ni颗粒粗化、氧化以及积碳等问题，导致电池性能衰减严重。相比之下，混合离子-电子导电钙钛矿氧化物以其氧化还原稳定性被认为是理想的替代材料。然而钙钛矿材料种类繁多，如何开发出高性能钙钛矿阴极材料是SOEC面临的重要挑战。此外，电极与电解质界面的热膨胀不匹配易引发分层和退化，如何进行界面修饰增强电池电化学性能和稳定性也是SOEC所面临的重要挑战。基于此本文研究内容主要包括以下三个方面。

（1）基于高熵工程策略，提出一种新型高熵钙钛矿La_0.6Sr_0.4Fe_0.4Co_0.3Ni_0.2Mo_0.1O_3-δ（HE-LSFCNM）作为SOEC高温电解CO₂的燃料电极材料。实验结果表明与传统低熵钙钛矿材料La_0.6Sr_0.4FeO_3-δ（LSF）相比，高熵钙钛矿HE-LSFCNM材料能产生更为丰富的氧空位、有效抑制了Sr偏析，极大地提升了CO₂电解的催化活性与稳定性。在1.5V和800℃条件下，电解电流密度从0.98A/cm²提升到1.44A/cm²，提升幅度为46.9%，同时在750℃，1.2V下稳定运行100小时，无明显衰减。

（2）基于高熵工程和阴离子掺杂协同策略，提出了一种F掺杂的高熵钙钛矿La_0.6Sr_0.4Fe_0.3Co_0.2Ni_0.2Mn_0.2Mo_0.1O_3-δ（LSFCNMM-F）作为SOEC电解二氧化碳的阴极材料，有效提升电池的电解性能与长期稳定性。F的掺杂会降低金属-氧键的强度、增加了氧空位的浓度、有效抑制了Sr偏析，从而显著促进了二氧化碳的吸附和活化。与采用纯高熵阴极的单电池相比，采用F掺杂高熵阴极的单电池，在800℃下其界面极化阻抗（R_p）降低了49.5%，由0.91Ω·cm²降至0.46Ω·cm²，在1.5V电压下展现出1.78A/cm²超高电流密度，电流密度提高了24.5%，显著高于同期许多文献报道的数值，体现出优越的电解性能，同时在750℃和1.2V条件下保持高达100小时的良好稳定性。

（3）基于界面工程策略，提出了一种酸腐蚀改性LSGM电解质表面的方法，该方法显著增加了电解质的表面粗糙度并减小了电解质厚度。通过简单的酸处理可以有效修复高温退火后的电解质表面，从而促进电极与电解质之间的化学键合，提升电化学性能和稳定性。具体而言，经酸处理后的LSGM电解质支撑型SOEC在800℃条件下表现出显著的电化学性能增强。在800℃和1.5V电压下，与230μm光滑电解质结构单电池相比（1.38A/cm²），酸刻蚀后约155μm粗糙界面电解质结构单电池的电流密度达到了2.25A/cm²，提升幅度为63%。为了排除电解质厚度的影响，研究了150μm光滑电解质结构单电池性能，在800℃和1.5V电压下，电流密度为1.58A/cm²，性能远低于酸刻蚀后155μm粗糙界面电解质结构单电池。150μm光滑电解质结构单电池的欧姆阻抗（R_Ω）为0.18Ω·cm²，而酸刻蚀后155μm粗糙界面电解质结构单电池的欧姆阻抗为0.135Ω·cm²，证明粗糙化电解质界面增强了电极与电解质的接触，降低了界面电阻。因此，粗糙化电解质界面能显著提升SOEC电解性能。

Solid oxide electrolysis cells (SOECs) are high-efficiency, all-solid-state energy conversion devices capable of converting electrical energy generated from sustainable sources into storable chemical energy. SOECs feature advantages such as cleanliness, high efficiency, flexibility in feedstocks, and the absence of noble metal catalysts, making them a critical component of future carbon neutrality technologies. Research has shown that the CO₂ reduction process is the rate-limiting step in SOEC CO₂ electrolysis, necessitating the development of cathode materials with high activity and stability as a primary research focus. Traditional Ni-based ceramics (e.g., Ni-YSZ) are widely used as cathodes due to their excellent catalytic activity and electrical conductivity. However, in high-temperature CO₂ electrolysis, these materials suffer from severe performance degradation due to Ni particle coarsening, oxidation, and carbon deposition. In contrast, mixed ionic-electronic conducting perovskite oxides, with their redox stability, are considered ideal alternative materials. Nevertheless, the vast diversity of perovskite materials poses a challenge in identifying high-performance cathodes for SOECs. Moreover, thermal expansion mismatches between the electrode and electrolyte often lead to degradation and delamination, highlighting the need for interface engineering to enhance the electrochemical performance and stability of SOECs. Based on these challenges, this study focuses on the following.

（1）Using a high-entropy engineering strategy, a novel high-entropy perovskite, La_0.6Sr_0.4Fe_0.4Co_0.4Ni_0.2Mo_0.1O_3-δ (HE-LSFCNM), was proposed as the fuel electrode material for SOEC high-temperature CO₂ electrolysis. Experimental results indicate that compared to the traditional low-entropy perovskite material La_0.6Sr_0.4FeO_3-δ(LSF), the high-entropy perovskite HE-LSFCNM exhibits enhanced catalytic activity and stability for CO₂ electrolysis, generates more abundant oxygen vacancies, and effectively suppresses Sr segregation. At 800°C and 1.5V, the current density increased from 0.98A/cm² to 1.44A/cm², a 46.9% improvement. Additionally, it demonstrated stable operation at 750°C and 1.2V for 100 hours with no significant degradation.

（2）Combining high-entropy engineering with anion doping, a fluorine-doped high-entropy perovskite, La_0.6Sr_0.4Fe_0.3Co_0.2Ni_0.2Mn_0.2Mo_0.1O_3-δ (LSFCNMM-F), was proposed as a cathode material for SOEC CO₂ electrolysis, effectively enhancing electrolysis performance and long-term stability. Fluorine doping reduces the strength of metal-oxygen bonds, increases oxygen vacancy concentration, and suppresses Sr segregation, thereby significantly promoting CO₂ adsorption and activation. Compared to pure high-entropy electrodes, single cells with this high-entropy and F-ion-coupled electrode exhibited a 49.5% reduction in interfacial polarization resistance (Rp) at 800°C, decreasing from 0.91 to 0.46Ω·cm², and sustained an ultra-high current density of 1.78A/cm² at 1.5V, a 24.5% improvement. This performance surpasses many contemporaneous reports, demonstrating superior capabilities and achieving stable operation at 750°C and 1.2V for 100 hours.

（3）Based on the interface engineering strategy, a surface modification method for LSGM electrolytes using acid etching was proposed. This approach significantly increased the surface roughness of the electrolyte and reduced its thickness. The simple acid treatment effectively repaired the electrolyte surface after high-temperature annealing, thereby enhancing the chemical bonding between the electrode and the electrolyte, as well as improving electrochemical performance and structural stability. Specifically, the acid-treated LSGM electrolyte-supported SOEC exhibited remarkable enhancement in electrochemical performance at 800°C. Under an applied voltage of 1.5V at 800°C, the acid-etched electrolyte with a rough interface (~155μm) achieved a current density of 2.25A/cm², representing a 63% increase compared to the smooth electrolyte (~230μm) with a current density of 1.38A/cm².To exclude the influence of electrolyte thickness, the performance of single cells with 150μm smooth electrolytes was investigated. At 800°C and 1.5V, the current density was 1.58 A/cm², which was significantly lower than that of the acid-etched rough interface electrolyte (~155μm). The ohmic resistance (R_Ω) of the smooth 150μm electrolyte cell was 0.18 Ω·cm², whereas that of the acid-etched rough interface electrolyte cell was 0.135 Ω·cm². This demonstrates that the roughened electrolyte interface enhanced electrode-electrolyte contact and reduced interfacial resistance. Therefore, roughening the electrolyte interface significantly improves the electrolysis performance of SOECs.