Hydride-ion conductors have attracted great interest as solid electrolytes due to the highly negative redox potential of the hydride ion. This study provides direction for effective design of materials that enhance H⁻ conductivity by exploring the relationship between cation size and hydride-ion conductivity using LnSrLiH₂O₂ (Ln = La, Pr, Nd, Sm, Gd), which are K₂NiF₄-type oxyhydride materials, synthesised under ambient and high pressures. The size of the A-site cation and the activation energy for H⁻ conduction were found to be strongly correlated. GdSrLiH₂O₂ exhibits the lowest activation energy of 67 kJ mol⁻¹. Crystal structure analysis and first principles calculations revealed that H⁻ is more displaced along the conduction pathway for smaller A-site cations in LnSrLiH₂O₂ due to lower repulsion between A-site cations and H⁻. These findings contribute to the further development of K₂NiF₄-type oxyhydrides with high H⁻ conductivities.

中文翻译：

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阳离子尺寸对LnSrLiH2O2（Ln = La，Pr，Nd，Sm，Gd）氢氧根中氢化物离子传导的影响

氢化物离子导体由于氢化物离子的高度负的氧化还原电势而作为固体电解质引起了极大的兴趣。本研究提供了方向的材料有效的设计增强ħ ^-通过探索使用阳离子尺寸和氢化离子传导性之间的关系电导率LnSrLiH ₂ ö ₂（Ln为镧，镨，钕，钐，钆），其为K ₂ NIF在常压和高压下合成的₄型羟基氧化物材料。A位阳离子并进行H活化能的大小^-被发现传导密切相关。GdSrLiH ₂ O ₂的活化能最低，为67 kJ mol ^-1。晶体结构分析和第一原理计算显示使得h ^-更沿着传导路径在LnSrLiH位移较小A位阳离子₂ Ò ₂由于较低的A位阳离子和H之间的排斥^- 。这些发现有助于K的进一步发展₂ NIF ₄型oxyhydrides高ħ ^-电导率。