Huang Wenlong, Lv Mingze, Li Ying, Ding Yushi, Lu Jiayao, Zhuang Chunsheng, Yue Pengfei, Zhang Wei
School of Metallurgy, Northeastern University China
Liaoning Key Laboratory for Metallurgical Sensor Materials and Technology, Northeastern University China.
RSC Adv. 2024 Nov 18;14(49):36782-36793. doi: 10.1039/d4ra06213b. eCollection 2024 Nov 11.
Perovskite-type solid electrolytes exhibit a diverse range of conductive properties due to the competition and coupling of multiple degrees of freedom. In perovskite structures, B-site and X-site ions form topological octahedral sublattices, which are instrumental in regulating transport properties for various charge carriers. However, research focused on the relationship between octahedral distortion and conductive properties in perovskite-type proton conductors remains limited. In this study, dopants such as Ge, Sn, Pr, and Ce were selected to modify the degree of BO octahedral distortion in CaHfScO . The relationships between conductivity, transport number, mobility, and the distortion degree were systematically investigated. The data indicate that both proton and oxygen ion mobilities initially increase with the octahedral distortion angle and then decrease, and CaHfSnScO with an octahedral distortion angle of 15.6°, exhibited the highest ionic mobilities and conductivities. The BO octahedral distortion appears to limit oxide ion conduction while enhancing the proton transport number. However, excessive doping generates additional oxygen vacancies, which adversely affect proton conduction. Under the combined influence of these factors, CaHfCeScO achieved the highest proton transport number of 0.503 at 800 °C. Overall, this work provides insights into the relationship between octahedral distortion and conductive properties, suggesting that co-doping is a feasible approach for further regulating carrier mobility properties.
由于多种自由度的竞争和耦合，钙钛矿型固体电解质表现出多种多样的导电特性。在钙钛矿结构中，B位和X位离子形成拓扑八面体亚晶格，这有助于调节各种电荷载流子的传输特性。然而，关于钙钛矿型质子导体中八面体畸变与导电特性之间关系的研究仍然有限。在本研究中，选择Ge、Sn、Pr和Ce等掺杂剂来改变CaHfScO中BO八面体的畸变程度。系统地研究了电导率、迁移数、迁移率与畸变程度之间的关系。数据表明，质子和氧离子迁移率最初都随着八面体畸变角的增加而增加，然后降低，八面体畸变角为15.6°的CaHfSnScO表现出最高的离子迁移率和电导率。BO八面体畸变似乎会限制氧离子传导，同时提高质子迁移数。然而，过度掺杂会产生额外的氧空位，这对质子传导产生不利影响。在这些因素的综合影响下，CaHfCeScO在800°C时实现了最高的质子迁移数0.503。总体而言，这项工作为八面体畸变与导电特性之间的关系提供了见解，表明共掺杂是进一步调节载流子迁移特性的一种可行方法。
