Visualization of Solid‐State Synthesis for Chalcogenide Na Superionic Conductors by in‐situ Neutron Diffraction
Visualization of Solid‐State Synthesis for Chalcogenide Na Superionic Conductors by in‐situ Neutron Diffraction
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原位中子衍射可视化硫属化物 Na 超离子导体的固态合成
DOI：
10.1002/cssc.202101839
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发表时间：
2021
期刊：
影响因子：
8.4
通讯作者：
Wang, Hui
中科院分区：
文献类型：
--
作者：
Halacoglu, Selim;Chertmanova, Sabina;Chen, Yan;Li, Yang;Rajapakse, Manthila;Sumanasekera, Gamini;Narayanan, Badri;Wang, Hui
硫族化物超离子钠（Na）导体作为全固态钠电池中的固体电解质（SE）具有巨大的潜力，具有高能量密度、安全性和成本效益的优点。固体钠离子导体的晶体结构和离子导电性能受到合成方法和加工参数的强烈影响。因此，了解合成过程对于控制结构和相以及获得具有所需性能的钠离子导体至关重要。得益于高通量和深穿透的飞行时间中子衍射（ND），原位实验能够跟踪两种硫族化物SE（Na3SbS4和Na3SbS3.5Se0.5）在固态合成过程中的实时结构变化。对于这两种导体，ND 结果揭示了加热时合成和熔融过程的快速一步反应，以及冷却时的再结晶和立方相到四方相变。此外，根据中子实验观察和理论模拟，发现 Se 掺杂会影响反应温度、晶格参数和结构稳定性。这项工作提出了利用原位ND技术对硫系钠离子导体的固体合成过程进行详细的结构研究，有利于新型固态导体的设计和合成。
Chalcogenide superionic sodium (Na) conductors have great potential as solid electrolytes (SEs) in all‐solid‐state Na batteries with advantages of high energy density, safety, and cost effectiveness. The crystal structures and ionically conductive properties of solid Na‐ion conductors are strongly influenced by synthetic approaches and processing parameters. Thus, understanding the synthesis process is essential to control the structures and phases and to obtain Na‐ion conductors with desirable properties. Thanks to the high‐flux and deep‐penetrating time‐of‐flight neutron diffraction (ND), in‐situ experiments were able to track real‐time structural changes of two chalcogenide SEs (Na3SbS4and Na3SbS3.5Se0.5) during the solid‐state synthesis. For these two conductors, the ND results revealed a fast one‐step reaction for the synthesis and the molten process when heating up, and the recrystallization as well as the cubic‐to‐tetragonal phase transition up on cooling. Moreover, Se‐doping was found to influence the reaction temperatures, lattice parameter, and structure stability based on neutron experimental observations and theoretical simulation. This work presents a detailed structural study using in‐situ ND technology for the solid synthesis process of chalcogenide Na‐ion conductors, beneficial for the design and synthesis of new solid‐state conductors.