Na Nonstoichiometric Modifications Unraveling the Sodium Ion Mobility and Transport Mechanism in Sodium Solid Electrolyte Na_(x)Zn_(2)TeO_(6)  

作　　者：SUN Huangyijia LI Xiaohui ZENG Xiaoling LIU Jian RAKHMATULLIN Aydar LOU Chenjie TANG Mingxue FERNANDEZ-CARRION Alberto Jose KUANG Xiaojun 

机构地区：[1]Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials,College of Chemistry and Bioengineering,Guilin University of Technology,Guilin 541004,P.R.China [2]Conditions Extremes et Materiaux:Haute Temperature et Irradiation(CNRS),CEMHTl,UPR 3079,Universite Orléans,Orleans F-45071,France [3]Tsinghua Shenzhen International Graduate School,Tsinghua University,Shenzhen 518055,P.R.China [4]School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,P.R.China

出　　处：《Chemical Research in Chinese Universities》2025年第2期296-304,共9页高等学校化学研究(英文版)

基　　金：supported by the National Natural Science Foundation of China(Nos.22205017,22090043);the Guangxi Natural Science Foundation,China(No.2019GXNSFGA245006);the Guilin University of Technology Research Startup Project,China(No.RD2400002912).

摘　　要：Sodium-ion conducting materials in sodium-ion battery have drawn widespread attention in energy storage technologies due to the advantages of low cost,high performance,and efficient environmental adaptability.Herein,bond valence site energy(BVSE)calculations were used to predict the sodium ion electrical performances by the Na nonstoichiometric modifications,and we have carried out fine experiments to modulate the sodium ion conductivity of Na_(x)Zn_(2)TeO_(6) guided by BVSE calculations.The optimized composition Na_(2.1)Zn_(2)TeO_(6) shows the superior sodium ionic conductivity of 5.3×10^(−3) S/cm at 190℃,with a low activation energy of 0.28 eV.The excess Na preferentially occupies the Na1 site with tetrahedral voids,which has a higher capacity for sodium ion migration,as revealed by the combined neutron powder diffraction technique with the 1D and 2D ^(23)Na solid-state NMR technique,which is responsible for the variations in sodium ion conductivity.In addition,it is worth noting that the resulting Na_(2.1)Zn_(2)TeO_(6) material maintains superior thermal and phase stability,as well as approximately the same thermal expansion coefficient values even during the temperature rise and fall cycles in the temperature range of 25–800°C.Furthermore,molecular dynamics simulations revealed that the sodium ions exhibit longrange anisotropic migration within the Na+interlayers of Na_(2.1)Zn_(2)TeO_(6).

关 键 词：Sodium solid electrolyte Bond valence site energy Nonstoichiometric modification 

分 类 号：O469[理学—凝聚态物理] TM912[理学—电子物理学]