Shekhtman Georgiy S, Sherstobitova Elena A, Shchelkanova Mariya S, Ilyina Evgenia A
Institute of High Temperature Electrochemistry, Ural Branch, Russian Academy of Sciences, 20 Akademicheskaya St., 620990 Ekaterinburg, Russia.
Materials (Basel). 2022 May 18;15(10):3612. doi: 10.3390/ma15103612.
With the view of developing new materials for sodium and sodium-ion power sources, NaFeO-SnO (0-50 mol.% SnO) powders were synthesized using a solid state method, and their phase composition and crystal structure were studied. A phase of the NaFeSnO composition with a layered rhombohedral structure of the α-NaFeO type was found when the tin dioxide content was 20 mol.%. The phase produced was of an O3 structural type. O3-type phases have sufficiently good performance when used as cathode materials in sodium-ion batteries and, moreover, often have a rather high sodium-cation conductivity. A two-dimensional migration map was built using Voronoi-Dirichlet partition and TOPOS software package. The sodium-ion conductivity of NaFeSnO at room temperature was rated low (10 S × cm at 20 °C), which may be the result of channels too narrow for Na migration. The results obtained show that the application of the compound studied in this work as a solid electrolyte in sodium power sources is unlikely. It is the potential use of NaFeSnO as the active material of cathodes in Na and Na-ion power sources that presents practical interest.
为了开发用于钠和钠离子电源的新材料，采用固态法合成了NaFeO - SnO（0 - 50摩尔％SnO）粉末，并研究了它们的相组成和晶体结构。当二氧化锡含量为20摩尔％时，发现了具有α - NaFeO型层状菱面体结构的NaFeSnO组成相。所产生的相为O3结构类型。O3型相在用作钠离子电池的阴极材料时具有足够好的性能，而且通常具有相当高的钠阳离子电导率。使用Voronoi - Dirichlet划分和TOPOS软件包构建了二维迁移图。NaFeSnO在室温下的钠离子电导率被评定为较低（20℃时为10⁻⁹ S/cm），这可能是由于Na迁移通道过窄所致。所得结果表明，这项工作中研究的化合物作为钠电源中的固体电解质不太可能应用。NaFeSnO作为钠和钠离子电源中阴极的活性材料的潜在用途具有实际意义。
